/* Fold a constant sub-tree into a single node for C-compiler
Copyright (C) 1987, 1988, 1992, 1993 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/*@@ Fix lossage on folding division of big integers. */
/*@@ This file should be rewritten to use an arbitrary precision
@@ representation for "struct tree_int_cst" and "struct tree_real_cst".
@@ Perhaps the routines could also be used for bc/dc, and made a lib.
@@ The routines that translate from the ap rep should
@@ warn if precision et. al. is lost.
@@ This would also make life easier when this technology is used
@@ for cross-compilers. */
/* The entry points in this file are fold, size_int and size_binop.
fold takes a tree as argument and returns a simplified tree.
size_binop takes a tree code for an arithmetic operation
and two operands that are trees, and produces a tree for the
result, assuming the type comes from `sizetype'.
size_int takes an integer value, and creates a tree constant
with type from `sizetype'. */
/* Handle floating overflow for `const_binop'. */
static jmp_buf float_error
;
static tree
const_binop ();
/* Yield nonzero if a signed left shift of A by B bits overflows. */
#define left_shift_overflows(a, b) ((a) != ((a) << (b)) >> (b))
/* Suppose A1 + B1 = SUM1, using 2's complement arithmetic ignoring overflow.
Suppose A, B and SUM have the same respective signs as A1, B1, and SUM1.
Then this yields nonzero if overflow occurred during the addition.
Overflow occurs if A and B have the same sign, but A and SUM differ in sign.
Use `^' to test whether signs differ, and `< 0' to isolate the sign. */
#define overflow_sum_sign(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
/* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
We do that by representing the two-word integer as MAX_SHORTS shorts,
with only 8 bits stored in each short, as a positive number. */
/* Unpack a two-word integer into MAX_SHORTS shorts.
LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
SHORTS points to the array of shorts. */
for (i
= 0; i
< MAX_SHORTS
/ 2; i
++)
shorts
[i
] = (low
>> (i
* 8)) & 0xff; shorts
[i
+ MAX_SHORTS
/ 2] = (hi
>> (i
* 8) & 0xff);/* Pack an array of MAX_SHORTS shorts into a two-word integer.
SHORTS points to the array of shorts.
The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
HOST_WIDE_INT lv
= 0, hv
= 0; for (i
= 0; i
< MAX_SHORTS
/ 2; i
++)
lv
|= (HOST_WIDE_INT
) shorts
[i
] << (i
* 8); hv
|= (HOST_WIDE_INT
) shorts
[i
+ MAX_SHORTS
/ 2] << (i
* 8);/* Make the integer constant T valid for its type
by setting to 0 or 1 all the bits in the constant
that don't belong in the type.
Yield 1 if a signed overflow occurs, 0 otherwise.
If OVERFLOW is nonzero, a signed overflow has already occurred
in calculating T, so propagate it. */
force_fit_type (t
, overflow
)
if (TREE_CODE (t
) != INTEGER_CST
)
low
= TREE_INT_CST_LOW (t
); high
= TREE_INT_CST_HIGH (t
); if (TREE_CODE (TREE_TYPE (t
)) == POINTER_TYPE
)
prec
= TYPE_PRECISION (TREE_TYPE (t
)); /* First clear all bits that are beyond the type's precision. */
if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
else if (prec
> HOST_BITS_PER_WIDE_INT
)
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
TREE_INT_CST_HIGH (t
) = 0;
if (prec
< HOST_BITS_PER_WIDE_INT
)
TREE_INT_CST_LOW (t
) &= ~((HOST_WIDE_INT
) (-1) << prec
);
/* Unsigned types do not suffer sign extension or overflow. */
if (TREE_UNSIGNED (TREE_TYPE (t
)))
/* If the value's sign bit is set, extend the sign. */
if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
&& (prec
> HOST_BITS_PER_WIDE_INT
& ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
: TREE_INT_CST_LOW (t
) & ((HOST_WIDE_INT
) 1 << (prec
- 1))))
set to 1 all the bits that are outside this type's precision. */
if (prec
> HOST_BITS_PER_WIDE_INT
)
|= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
TREE_INT_CST_HIGH (t
) = -1;
if (prec
< HOST_BITS_PER_WIDE_INT
)
TREE_INT_CST_LOW (t
) |= ((HOST_WIDE_INT
) (-1) << prec
);
/* Yield nonzero if signed overflow occurred. */
((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
/* Add two doubleword integers with doubleword result.
Each argument is given as two `HOST_WIDE_INT' pieces.
One argument is L1 and H1; the other, L2 and H2.
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV.
We use the 8-shorts representation internally. */
add_double (l1
, h1
, l2
, h2
, lv
, hv
)
HOST_WIDE_INT l1
, h1
, l2
, h2
; for (i
= 0; i
< MAX_SHORTS
; i
++)
carry
+= arg1
[i
] + arg2
[i
]; return overflow_sum_sign (h1
, h2
, *hv
);
/* Negate a doubleword integer with doubleword result.
Return nonzero if the operation overflows, assuming it's signed.
The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV.
We use the 8-shorts representation internally. */
neg_double (l1
, h1
, lv
, hv
)
/* Multiply two doubleword integers with doubleword result.
Return nonzero if the operation overflows, assuming it's signed.
Each argument is given as two `HOST_WIDE_INT' pieces.
One argument is L1 and H1; the other, L2 and H2.
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV.
We use the 8-shorts representation internally. */
mul_double (l1
, h1
, l2
, h2
, lv
, hv
)
HOST_WIDE_INT l1
, h1
, l2
, h2
; short prod
[MAX_SHORTS
* 2];
HOST_WIDE_INT toplow
, tophigh
, neglow
, neghigh
; /* These cases are used extensively, arising from pointer combinations. */
int overflow
= left_shift_overflows (h1
, 1);
unsigned HOST_WIDE_INT temp
= l1
+ l1
;
*hv
= (h1
<< 1) + (temp
< l1
);
int overflow
= left_shift_overflows (h1
, 2);
unsigned HOST_WIDE_INT temp
= l1
+ l1
;
h1
= (h1
<< 2) + ((temp
< l1
) << 1); int overflow
= left_shift_overflows (h1
, 3);
unsigned HOST_WIDE_INT temp
= l1
+ l1
;
h1
= (h1
<< 3) + ((temp
< l1
) << 2); bzero (prod
, sizeof prod
);
for (i
= 0; i
< MAX_SHORTS
; i
++)
for (j
= 0; j
< MAX_SHORTS
; j
++)
carry
= arg1
[i
] * arg2
[j
]; decode (prod
, lv
, hv
); /* This ignores
prod[MAX_SHORTS] -> prod[MAX_SHORTS*2-1] */
/* Check for overflow by calculating the top half of the answer in full;
it should agree with the low half's sign bit. */
decode (prod
+MAX_SHORTS
, &toplow
, &tophigh
);
neg_double (l2
, h2
, &neglow
, &neghigh
);
add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
neg_double (l1
, h1
, &neglow
, &neghigh
);
add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
/* Shift the doubleword integer in L1, H1 left by COUNT places
keeping only PREC bits of result.
Shift right if COUNT is negative.
ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
lshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
rshift_double (l1
, h1
, - count
, prec
, lv
, hv
, arith
);
for (i
= 0; i
< MAX_SHORTS
; i
++)
/* Shift the doubleword integer in L1, H1 right by COUNT places
keeping only PREC bits of result. COUNT must be positive.
ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
rshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
HOST_WIDE_INT l1
, h1
, count
, prec
; carry
= arith
&& arg1
[7] >> 7; for (i
= MAX_SHORTS
- 1; i
>= 0; i
--)
arg1
[i
] = (carry
>> 1) & 0xff;/* Rotate the doubldword integer in L1, H1 left by COUNT places
keeping only PREC bits of result.
Rotate right if COUNT is negative.
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
lrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
HOST_WIDE_INT l1
, h1
, count
, prec
; rrotate_double (l1
, h1
, - count
, prec
, lv
, hv
);
carry
= arg1
[MAX_SHORTS
- 1] >> 7; for (i
= 0; i
< MAX_SHORTS
; i
++)
/* Rotate the doubleword integer in L1, H1 left by COUNT places
keeping only PREC bits of result. COUNT must be positive.
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
rrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
HOST_WIDE_INT l1
, h1
, count
, prec
; for (i
= MAX_SHORTS
- 1; i
>= 0; i
--)
arg1
[i
] = (carry
>> 1) & 0xff;/* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
CODE is a tree code for a kind of division, one of
TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
It controls how the quotient is rounded to a integer.
Return nonzero if the operation overflows.
UNS nonzero says do unsigned division. */
div_and_round_double (code
, uns
,
lnum_orig
, hnum_orig
, lden_orig
, hden_orig
, HOST_WIDE_INT lnum_orig
, hnum_orig
; /* num == numerator == dividend */ HOST_WIDE_INT lden_orig
, hden_orig
; /* den == denominator == divisor */ HOST_WIDE_INT
*lquo
, *hquo
, *lrem
, *hrem
; short num
[MAX_SHORTS
+ 1]; /* extra element for scaling. */
short den
[MAX_SHORTS
], quo
[MAX_SHORTS
];
HOST_WIDE_INT lnum
= lnum_orig
; HOST_WIDE_INT hnum
= hnum_orig
; HOST_WIDE_INT lden
= lden_orig
; HOST_WIDE_INT hden
= hden_orig
; if ((hden
== 0) && (lden
== 0))
/* calculate quotient sign and convert operands to unsigned. */
/* (minimum integer) / (-1) is the only overflow case. */
if (neg_double (lnum
, hnum
, &lnum
, &hnum
) && (lden
& hden
) == -1)
neg_double (lden
, hden
, &lden
, &hden
);
if (hnum
== 0 && hden
== 0)
/* This unsigned division rounds toward zero. */
*lquo
= lnum
/ (unsigned HOST_WIDE_INT
) lden
;
{ /* trivial case: dividend < divisor */
/* hden != 0 already checked. */
bzero (num
, sizeof num
); /* to zero 9th element */
encode (num
, lnum
, hnum
);
encode (den
, lden
, hden
);
/* This code requires more than just hden == 0.
We also have to require that we don't need more than three bytes
to hold CARRY. If we ever did need four bytes to hold it, we
would lose part of it when computing WORK on the next round. */
if (hden
== 0 && (((unsigned HOST_WIDE_INT
) lden
<< 8) >> 8) == lden
)
{ /* simpler algorithm */
/* hnum != 0 already checked. */
for (i
= MAX_SHORTS
- 1; i
>= 0; i
--)
work
= num
[i
] + (carry
<< 8); quo
[i
] = work
/ (unsigned HOST_WIDE_INT
) lden
; carry
= work
% (unsigned HOST_WIDE_INT
) lden
; else { /* full double precision,
with thanks to Don Knuth's
"Seminumerical Algorithms". */
int quo_est
, scale
, num_hi_sig
, den_hi_sig
, quo_hi_sig
;
/* Find the highest non-zero divisor digit. */
for (i
= MAX_SHORTS
- 1; ; i
--)
for (i
= MAX_SHORTS
- 1; ; i
--)
quo_hi_sig
= num_hi_sig
- den_hi_sig
+ 1; /* Insure that the first digit of the divisor is at least BASE/2.
This is required by the quotient digit estimation algorithm. */
scale
= BASE
/ (den
[den_hi_sig
] + 1); if (scale
> 1) { /* scale divisor and dividend */
for (i
= 0; i
<= MAX_SHORTS
- 1; i
++) {
work
= (num
[i
] * scale
) + carry
; if (num
[i
] != 0) num_hi_sig
= i
;
for (i
= 0; i
<= MAX_SHORTS
- 1; i
++) {
work
= (den
[i
] * scale
) + carry
; if (den
[i
] != 0) den_hi_sig
= i
;
for (i
= quo_hi_sig
; i
> 0; i
--) {
/* guess the next quotient digit, quo_est, by dividing the first
two remaining dividend digits by the high order quotient digit.
quo_est is never low and is at most 2 high. */
int num_hi
; /* index of highest remaining dividend digit */
work
= (num
[num_hi
] * BASE
) + (num_hi
> 0 ? num
[num_hi
- 1] : 0); if (num
[num_hi
] != den
[den_hi_sig
]) {
quo_est
= work
/ den
[den_hi_sig
]; /* refine quo_est so it's usually correct, and at most one high. */
while ((den
[den_hi_sig
- 1] * quo_est
)
> (((work
- (quo_est
* den
[den_hi_sig
])) * BASE
)
+ ((num_hi
- 1) > 0 ? num
[num_hi
- 2] : 0)))
/* Try QUO_EST as the quotient digit, by multiplying the
divisor by QUO_EST and subtracting from the remaining dividend.
Keep in mind that QUO_EST is the I - 1st digit. */
for (j
= 0; j
<= den_hi_sig
; j
++)
work
= num
[i
+ j
- 1] - (quo_est
* den
[j
]) + carry
; /* if quo_est was high by one, then num[i] went negative and
we need to correct things. */
carry
= 0; /* add divisor back in */ for (j
= 0; j
<= den_hi_sig
; j
++)
work
= num
[i
+ j
- 1] + den
[j
] + carry
; /* store the quotient digit. */
decode (quo
, lquo
, hquo
);
/* if result is negative, make it so. */
neg_double (*lquo
, *hquo
, lquo
, hquo
);
/* compute trial remainder: rem = num - (quo * den) */
mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
neg_double (*lrem
, *hrem
, lrem
, hrem
);
add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
case TRUNC_MOD_EXPR
: /* round toward zero */
case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
case FLOOR_MOD_EXPR
: /* round toward negative infinity */
if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
case CEIL_MOD_EXPR
: /* round toward positive infinity */
if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
case ROUND_MOD_EXPR
: /* round to closest integer */
HOST_WIDE_INT labs_rem
= *lrem
, habs_rem
= *hrem
; HOST_WIDE_INT labs_den
= lden
, habs_den
= hden
, ltwice
, htwice
; /* get absolute values */
if (*hrem
< 0) neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
if (hden
< 0) neg_double (lden
, hden
, &labs_den
, &habs_den
);
/* if (2 * abs (lrem) >= abs (lden)) */
mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
labs_rem
, habs_rem
, <wice
, &htwice
); if (((unsigned HOST_WIDE_INT
) habs_den
< (unsigned HOST_WIDE_INT
) htwice
)
|| (((unsigned HOST_WIDE_INT
) habs_den
== (unsigned HOST_WIDE_INT
) htwice
)
&& ((HOST_WIDE_INT
unsigned) labs_den
< (unsigned HOST_WIDE_INT
) ltwice
)))
add_double (*lquo
, *hquo
,
(HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
/* compute true remainder: rem = num - (quo * den) */
mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
neg_double (*lrem
, *hrem
, lrem
, hrem
);
add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
/* Effectively truncate a real value to represent
the nearest possible value in a narrower mode.
The result is actually represented in the same data type as the argument,
but its value is usually different. */
real_value_truncate (mode
, arg
)
/* Make sure the value is actually stored in memory before we turn off
jmp_buf handler
, old_handler
;
error ("floating overflow");
handled
= push_float_handler (handler
, old_handler
); value
= REAL_VALUE_TRUNCATE (mode
, arg
); pop_float_handler (handled
, old_handler
);
#if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
/* Check for infinity in an IEEE double precision number. */
/* The IEEE 64-bit double format. */
if (u
.big_endian
.sign
== 1)
return (u
.big_endian
.exponent
== 2047
&& u
.big_endian
.mantissa1
== 0
&& u
.big_endian
.mantissa2
== 0);
return (u
.little_endian
.exponent
== 2047
&& u
.little_endian
.mantissa1
== 0
&& u
.little_endian
.mantissa2
== 0);
/* Check whether an IEEE double precision number is a NaN. */
/* The IEEE 64-bit double format. */
if (u
.big_endian
.sign
== 1)
return (u
.big_endian
.exponent
== 2047
&& (u
.big_endian
.mantissa1
!= 0
|| u
.big_endian
.mantissa2
!= 0));
return (u
.little_endian
.exponent
== 2047
&& (u
.little_endian
.mantissa1
!= 0
|| u
.little_endian
.mantissa2
!= 0));
/* Check for a negative IEEE double precision number. */
/* The IEEE 64-bit double format. */
if (u
.big_endian
.sign
== 1)
return u
.big_endian
.sign
;
return u
.little_endian
.sign
;
#else /* Target not IEEE */
/* Let's assume other float formats don't have infinity.
(This can be overridden by redefining REAL_VALUE_ISINF.) */
/* Let's assume other float formats don't have NaNs.
(This can be overridden by redefining REAL_VALUE_ISNAN.) */
/* Let's assume other float formats don't have minus zero.
(This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
#endif /* Target not IEEE */
#endif /* no REAL_ARITHMETIC */
/* Split a tree IN into a constant and a variable part
that could be combined with CODE to make IN.
CODE must be a commutative arithmetic operation.
Store the constant part into *CONP and the variable in &VARP.
Return 1 if this was done; zero means the tree IN did not decompose
If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR.
Therefore, we must tell the caller whether the variable part
was subtracted. We do this by storing 1 or -1 into *VARSIGNP.
The value stored is the coefficient for the variable term.
The constant term we return should always be added;
we negate it if necessary. */
split_tree (in
, code
, varp
, conp
, varsignp
)
register tree outtype
= TREE_TYPE (in
);
/* Strip any conversions that don't change the machine mode. */
while ((TREE_CODE (in
) == NOP_EXPR
|| TREE_CODE (in
) == CONVERT_EXPR
)
&& (TYPE_MODE (TREE_TYPE (in
))
== TYPE_MODE (TREE_TYPE (TREE_OPERAND (in
, 0)))))
in
= TREE_OPERAND (in
, 0); if (TREE_CODE (in
) == code
|| (! FLOAT_TYPE_P (TREE_TYPE (in
))
/* We can associate addition and subtraction together
(even though the C standard doesn't say so)
for integers because the value is not affected.
For reals, the value might be affected, so we can't. */
&& ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
|| (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
enum tree_code code
= TREE_CODE (TREE_OPERAND (in
, 0));
*conp
= TREE_OPERAND (in
, 0);
*varp
= TREE_OPERAND (in
, 1);
if (TYPE_MODE (TREE_TYPE (*varp
)) != TYPE_MODE (outtype
)
&& TREE_TYPE (*varp
) != outtype
)
*varp
= convert (outtype
, *varp
);
*varsignp
= (TREE_CODE (in
) == MINUS_EXPR
) ? -1 : 1;
if (TREE_CONSTANT (TREE_OPERAND (in
, 1)))
*conp
= TREE_OPERAND (in
, 1);
*varp
= TREE_OPERAND (in
, 0);
if (TYPE_MODE (TREE_TYPE (*varp
)) != TYPE_MODE (outtype
)
&& TREE_TYPE (*varp
) != outtype
)
*varp
= convert (outtype
, *varp
);
if (TREE_CODE (in
) == MINUS_EXPR
)
/* If operation is subtraction and constant is second,
must negate it to get an additive constant.
And this cannot be done unless it is a manifest constant.
It could also be the address of a static variable.
We cannot negate that, so give up. */
if (TREE_CODE (*conp
) == INTEGER_CST
)
/* Subtracting from integer_zero_node loses for long long. */
*conp
= fold (build1 (NEGATE_EXPR
, TREE_TYPE (*conp
), *conp
));
if (TREE_CONSTANT (TREE_OPERAND (in
, 0)))
*conp
= TREE_OPERAND (in
, 0);
*varp
= TREE_OPERAND (in
, 1);
if (TYPE_MODE (TREE_TYPE (*varp
)) != TYPE_MODE (outtype
)
&& TREE_TYPE (*varp
) != outtype
)
*varp
= convert (outtype
, *varp
);
*varsignp
= (TREE_CODE (in
) == MINUS_EXPR
) ? -1 : 1;
/* Combine two constants NUM and ARG2 under operation CODE
to produce a new constant.
We assume ARG1 and ARG2 have the same data type,
or at least are the same kind of constant and the same machine mode.
If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
const_binop (code
, arg1
, arg2
, notrunc
)
register tree arg1
, arg2
;
if (TREE_CODE (arg1
) == INTEGER_CST
)
register HOST_WIDE_INT int1l
= TREE_INT_CST_LOW (arg1
);
register HOST_WIDE_INT int1h
= TREE_INT_CST_HIGH (arg1
);
HOST_WIDE_INT int2l
= TREE_INT_CST_LOW (arg2
); HOST_WIDE_INT int2h
= TREE_INT_CST_HIGH (arg2
); HOST_WIDE_INT garbagel
, garbageh
; int uns
= TREE_UNSIGNED (TREE_TYPE (arg1
));
t
= build_int_2 (int1l
| int2l
, int1h
| int2h
); t
= build_int_2 (int1l
^ int2l
, int1h
^ int2h
); t
= build_int_2 (int1l
& int2l
, int1h
& int2h
); t
= build_int_2 (int1l
& ~int2l
, int1h
& ~int2h
); /* It's unclear from the C standard whether shifts can overflow.
The following code ignores overflow; perhaps a C standard
interpretation ruling is needed. */
lshift_double (int1l
, int1h
, int2l
,
TYPE_PRECISION (TREE_TYPE (arg1
)),
t
= build_int_2 (low
, hi
); TREE_TYPE (t
) = TREE_TYPE (arg1
);
TREE_CONSTANT_OVERFLOW (t
)
= TREE_CONSTANT_OVERFLOW (arg1
) | TREE_CONSTANT_OVERFLOW (arg2
);
lrotate_double (int1l
, int1h
, int2l
,
TYPE_PRECISION (TREE_TYPE (arg1
)),
t
= build_int_2 (low
, hi
); if ((unsigned HOST_WIDE_INT
) int2l
< int1l
)
t
= build_int_2 (int2l
, int2h
); if ((unsigned HOST_WIDE_INT
) int1l
< int2l
)
t
= build_int_2 (int1l
, int1h
); overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
); t
= build_int_2 (low
, hi
); if (int2h
== 0 && int2l
== 0)
t
= build_int_2 (int1l
, int1h
); neg_double (int2l
, int2h
, &low
, &hi
);
add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
overflow
= overflow_sum_sign (hi
, int2h
, int1h
); t
= build_int_2 (low
, hi
); /* Optimize simple cases. */
unsigned HOST_WIDE_INT temp
;
t
= build_int_2 (int2l
, int2h
); overflow
= left_shift_overflows (int2h
, 1); int2h
= (int2h
<< 1) + (temp
< int2l
); t
= build_int_2 (temp
, int2h
);#if 0 /* This code can lose carries. */
temp
= int2l
+ int2l
+ int2l
; int2h
= int2h
* 3 + (temp
< int2l
); t
= build_int_2 (temp
, int2h
); overflow
= left_shift_overflows (int2h
, 2); int2h
= (int2h
<< 2) + ((temp
< int2l
) << 1); t
= build_int_2 (temp
, int2h
); overflow
= left_shift_overflows (int2h
, 3); int2h
= (int2h
<< 3) + ((temp
< int2l
) << 2); int2h
+= (temp
< int2l
) << 1; t
= build_int_2 (temp
, int2h
); t
= build_int_2 (int1l
, int1h
); overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
); t
= build_int_2 (low
, hi
); case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
/* This is a shortcut for a common special case.
It reduces the number of tree nodes generated
if (int2h
== 0 && int2l
> 0
&& TREE_TYPE (arg1
) == sizetype
&& int1h
== 0 && int1l
>= 0)
if (code
== CEIL_DIV_EXPR
)
return size_int (int1l
/ int2l
);
if (int2h
== 0 && int2l
== 1)
t
= build_int_2 (int1l
, int1h
); if (int1l
== int2l
&& int1h
== int2h
)
if ((int1l
| int1h
) == 0)
overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
, &low
, &hi
, &garbagel
, &garbageh
);
t
= build_int_2 (low
, hi
); case TRUNC_MOD_EXPR
: case ROUND_MOD_EXPR
:
case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
, &garbagel
, &garbageh
, &low
, &hi
);
t
= build_int_2 (low
, hi
); low
= (((unsigned HOST_WIDE_INT
) int1h
< (unsigned HOST_WIDE_INT
) int2h
)
|| (((unsigned HOST_WIDE_INT
) int1h
== (unsigned HOST_WIDE_INT
) int2h
)
&& ((unsigned HOST_WIDE_INT
) int1l
< (unsigned HOST_WIDE_INT
) int2l
)));
&& ((unsigned HOST_WIDE_INT
) int1l
< (unsigned HOST_WIDE_INT
) int2l
)));
if (low
== (code
== MIN_EXPR
))
t
= build_int_2 (int1l
, int1h
); t
= build_int_2 (int2l
, int2h
); TREE_TYPE (t
) = TREE_TYPE (arg1
);
TREE_CONSTANT_OVERFLOW (t
)
= ((notrunc
? !uns
&& overflow
: force_fit_type (t
, overflow
))
| TREE_CONSTANT_OVERFLOW (arg1
)
| TREE_CONSTANT_OVERFLOW (arg2
));
#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1
) == REAL_CST
)
d1
= TREE_REAL_CST (arg1
); d2
= TREE_REAL_CST (arg2
); if (setjmp (float_error
))
pedwarn ("floating overflow in constant expression");
return build (code
, TREE_TYPE (arg1
), arg1
, arg2
);
set_float_handler (float_error
);
REAL_ARITHMETIC (value
, code
, d1
, d2
);
#endif /* no REAL_ARITHMETIC */
t
= build_real (TREE_TYPE (arg1
), real_value_truncate (TYPE_MODE (TREE_TYPE (arg1
)), value
));
set_float_handler (NULL_PTR
);
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
if (TREE_CODE (arg1
) == COMPLEX_CST
)
register tree r1
= TREE_REALPART (arg1
);
register tree i1
= TREE_IMAGPART (arg1
);
register tree r2
= TREE_REALPART (arg2
);
register tree i2
= TREE_IMAGPART (arg2
);
t
= build_complex (const_binop (PLUS_EXPR
, r1
, r2
, notrunc
), const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
t
= build_complex (const_binop (MINUS_EXPR
, r1
, r2
, notrunc
), const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
t
= build_complex (const_binop (MINUS_EXPR
, = const_binop (PLUS_EXPR
,
const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
t
= build_complex (const_binop (RDIV_EXPR
, const_binop (MULT_EXPR
, r1
, r2
, notrunc
),
const_binop (MULT_EXPR
, i1
, i2
, notrunc
),
const_binop (MULT_EXPR
, i1
, r2
, notrunc
),
const_binop (MULT_EXPR
, r1
, i2
, notrunc
),
TREE_TYPE (t
) = TREE_TYPE (arg1
);
/* Return an INTEGER_CST with value V and type from `sizetype'. */
/* Type-size nodes already made for small sizes. */
static tree size_table
[2*HOST_BITS_PER_WIDE_INT
+ 1];
if (number
< 2*HOST_BITS_PER_WIDE_INT
+ 1
&& size_table
[number
] != 0)
return size_table
[number
];
if (number
< 2*HOST_BITS_PER_WIDE_INT
+ 1)
push_obstacks_nochange ();
/* Make this a permanent node. */
end_temporary_allocation ();
t
= build_int_2 (number
, 0); TREE_TYPE (t
) = sizetype
;
t
= build_int_2 (number
, 0); TREE_TYPE (t
) = sizetype
;
/* Combine operands OP1 and OP2 with arithmetic operation CODE.
CODE is a tree code. Data type is taken from `sizetype',
If the operands are constant, so is the result. */
size_binop (code
, arg0
, arg1
)
/* Handle the special case of two integer constants faster. */
if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
/* And some specific cases even faster than that. */
&& TREE_INT_CST_LOW (arg0
) == 0
&& TREE_INT_CST_HIGH (arg0
) == 0)
&& TREE_INT_CST_LOW (arg1
) == 0
&& TREE_INT_CST_HIGH (arg1
) == 0)
&& TREE_INT_CST_LOW (arg0
) == 1
&& TREE_INT_CST_HIGH (arg0
) == 0)
/* Handle general case of two integer constants. */
return const_binop (code
, arg0
, arg1
, 1);
if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
return fold (build (code
, sizetype
, arg0
, arg1
));
/* Given T, a tree representing type conversion of ARG1, a constant,
return a constant tree representing the result of conversion. */
register tree type
= TREE_TYPE (t
);
if (TREE_CODE (type
) == POINTER_TYPE
|| INTEGRAL_TYPE_P (type
))
if (TREE_CODE (arg1
) == INTEGER_CST
)
/* Given an integer constant, make new constant with new type,
appropriately sign-extended or truncated. */
t
= build_int_2 (TREE_INT_CST_LOW (arg1
), TREE_INT_CST_HIGH (arg1
));
/* Indicate an overflow if (1) ARG1 already overflowed,
or (2) ARG1 is a too-large unsigned value and T is signed,
or (3) force_fit_type indicates an overflow.
force_fit_type can't detect (2), since it sees only T's type. */
TREE_CONSTANT_OVERFLOW (t
) =
(TREE_CONSTANT_OVERFLOW (arg1
)
| (TREE_INT_CST_HIGH (arg1
) < 0
& TREE_UNSIGNED (type
) < TREE_UNSIGNED (TREE_TYPE (arg1
)))
| force_fit_type (t
, 0));
#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
else if (TREE_CODE (arg1
) == REAL_CST
)
l
= real_value_from_int_cst (TYPE_MIN_VALUE (type
)); x
= TREE_REAL_CST (arg1
); u
= real_value_from_int_cst (TYPE_MAX_VALUE (type
)); /* See if X will be in range after truncation towards 0.
To compensate for truncation, move the bounds away from 0,
but reject if X exactly equals the adjusted bounds. */
REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
if (! (REAL_VALUES_LESS (l
, x
) && REAL_VALUES_LESS (x
, u
)))
pedwarn ("real constant out of range for integer conversion");
= (HOST_WIDE_INT
) 1 << (HOST_BITS_PER_WIDE_INT
/ 2);
d
= TREE_REAL_CST (arg1
); high
= (HOST_WIDE_INT
) (d
/ half_word
/ half_word
); d
-= (REAL_VALUE_TYPE
) high
* half_word
* half_word
; if (d
>= (REAL_VALUE_TYPE
) half_word
* half_word
/ 2)
low
= d
- (REAL_VALUE_TYPE
) half_word
* half_word
/ 2; low
|= (HOST_WIDE_INT
) -1 << (HOST_BITS_PER_WIDE_INT
- 1); if (TREE_REAL_CST (arg1
) < 0)
neg_double (low
, high
, &low
, &high
);
t
= build_int_2 (low
, high
); REAL_VALUE_TO_INT (&low
, &high
, (TREE_REAL_CST (arg1
)));
t
= build_int_2 (low
, high
);#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
else if (TREE_CODE (type
) == REAL_TYPE
)
#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1
) == INTEGER_CST
)
return build_real_from_int_cst (type
, arg1
);
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
if (TREE_CODE (arg1
) == REAL_CST
)
if (setjmp (float_error
))
pedwarn ("floating overflow in constant expression");
set_float_handler (float_error
);
t
= build_real (type
, real_value_truncate (TYPE_MODE (type
), set_float_handler (NULL_PTR
);
/* Return an expr equal to X but certainly not valid as an lvalue.
Also make sure it is not valid as an null pointer constant. */
/* These things are certainly not lvalues. */
if (TREE_CODE (x
) == NON_LVALUE_EXPR
|| TREE_CODE (x
) == INTEGER_CST
|| TREE_CODE (x
) == REAL_CST
|| TREE_CODE (x
) == STRING_CST
|| TREE_CODE (x
) == ADDR_EXPR
)
if (TREE_CODE (x
) == INTEGER_CST
&& integer_zerop (x
))
/* Use NOP_EXPR instead of NON_LVALUE_EXPR
so convert_for_assignment won't strip it.
This is so this 0 won't be treated as a null pointer constant. */
result
= build1 (NOP_EXPR
, TREE_TYPE (x
), x
); TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
); TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
/* Given a tree comparison code, return the code that is the logical inverse
of the given code. It is not safe to do this for floating-point
comparisons, except for NE_EXPR and EQ_EXPR. */
invert_tree_comparison (code
)
/* Similar, but return the comparison that results if the operands are
swapped. This is safe for floating-point. */
swap_tree_comparison (code
)
/* Return nonzero if two operands are necessarily equal.
If ONLY_CONST is non-zero, only return non-zero for constants.
This function tests whether the operands are indistinguishable;
it does not test whether they are equal using C's == operation.
The distinction is important for IEEE floating point, because
(1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
(2) two NaNs may be indistinguishable, but NaN!=NaN. */
operand_equal_p (arg0
, arg1
, only_const
)
/* If both types don't have the same signedness, then we can't consider
them equal. We must check this before the STRIP_NOPS calls
because they may change the signedness of the arguments. */
if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
/* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
We don't care about side effects in that case because the SAVE_EXPR
takes care of that for us. */
if (TREE_CODE (arg0
) == SAVE_EXPR
&& arg0
== arg1
)
if (TREE_SIDE_EFFECTS (arg0
) || TREE_SIDE_EFFECTS (arg1
))
if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
&& TREE_CODE (arg0
) == ADDR_EXPR
&& TREE_OPERAND (arg0
, 0) == TREE_OPERAND (arg1
, 0))
if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
&& TREE_CODE (arg0
) == INTEGER_CST
&& TREE_INT_CST_LOW (arg0
) == TREE_INT_CST_LOW (arg1
)
&& TREE_INT_CST_HIGH (arg0
) == TREE_INT_CST_HIGH (arg1
))
/* Detect when real constants are equal. */
if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
&& TREE_CODE (arg0
) == REAL_CST
)
return !bcmp (&TREE_REAL_CST (arg0
), &TREE_REAL_CST (arg1
),
sizeof (REAL_VALUE_TYPE
));
if (TREE_CODE (arg0
) != TREE_CODE (arg1
))
/* This is needed for conversions and for COMPONENT_REF.
Might as well play it safe and always test this. */
if (TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
/* Two conversions are equal only if signedness and modes match. */
if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
&& (TREE_UNSIGNED (TREE_TYPE (arg0
))
!= TREE_UNSIGNED (TREE_TYPE (arg1
))))
return operand_equal_p (TREE_OPERAND (arg0
, 0),
TREE_OPERAND (arg1
, 0), 0);
return (operand_equal_p (TREE_OPERAND (arg0
, 0),
TREE_OPERAND (arg1
, 0), 0)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
TREE_OPERAND (arg1
, 1), 0));
switch (TREE_CODE (arg0
))
return operand_equal_p (TREE_OPERAND (arg0
, 0),
TREE_OPERAND (arg1
, 0), 0);
return (operand_equal_p (TREE_OPERAND (arg0
, 0),
TREE_OPERAND (arg1
, 0), 0)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
TREE_OPERAND (arg1
, 1), 0));
return (operand_equal_p (TREE_OPERAND (arg0
, 0),
TREE_OPERAND (arg1
, 0), 0)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
TREE_OPERAND (arg1
, 1), 0)
&& operand_equal_p (TREE_OPERAND (arg0
, 2),
TREE_OPERAND (arg1
, 2), 0));
/* Similar to operand_equal_p, but see if ARG0 might have been made by
shorten_compare from ARG1 when ARG1 was being compared with OTHER.
When in doubt, return 0. */
operand_equal_for_comparison_p (arg0
, arg1
, other
)
int unsignedp1
, unsignedpo
;
tree primarg1
, primother
; if (operand_equal_p (arg0
, arg1
, 0))
if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
/* Duplicate what shorten_compare does to ARG1 and see if that gives the
actual comparison operand, ARG0.
First throw away any conversions to wider types
already present in the operands. */
primarg1
= get_narrower (arg1
, &unsignedp1
); primother
= get_narrower (other
, &unsignedpo
); correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
)); if (unsignedp1
== unsignedpo
&& TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
&& TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
tree type
= TREE_TYPE (arg0
); /* Make sure shorter operand is extended the right way
to match the longer operand. */
primarg1
= convert (signed_or_unsigned_type (unsignedp1
, if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
/* See if ARG is an expression that is either a comparison or is performing
arithmetic on comparisons. The comparisons must only be comparing
two different values, which will be stored in *CVAL1 and *CVAL2; if
they are non-zero it means that some operands have already been found.
No variables may be used anywhere else in the expression except in the
If this is true, return 1. Otherwise, return zero. */
twoval_comparison_p (arg
, cval1
, cval2
)
enum tree_code code
= TREE_CODE (arg
);
char class = TREE_CODE_CLASS (code
);
/* We can handle some of the 'e' cases here. */
&& (code
== TRUTH_NOT_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0)))
&& (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
|| code
== COMPOUND_EXPR
))
return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
);
return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
)
&& twoval_comparison_p (TREE_OPERAND (arg
, 1), cval1
, cval2
));
return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
)
&& twoval_comparison_p (TREE_OPERAND (arg
, 1), cval1
, cval2
)
&& twoval_comparison_p (TREE_OPERAND (arg
, 2),
/* First see if we can handle the first operand, then the second. For
the second operand, we know *CVAL1 can't be zero. It must be that
one side of the comparison is each of the values; test for the
case where this isn't true by failing if the two operands
if (operand_equal_p (TREE_OPERAND (arg
, 0),
TREE_OPERAND (arg
, 1), 0))
*cval1
= TREE_OPERAND (arg
, 0);
else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
*cval2
= TREE_OPERAND (arg
, 0);
else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
*cval2
= TREE_OPERAND (arg
, 1);
else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
/* ARG is a tree that is known to contain just arithmetic operations and
comparisons. Evaluate the operations in the tree substituting NEW0 for
any occurrence of OLD0 as an operand of a comparison and likewise for
eval_subst (arg
, old0
, new0
, old1
, new1
)
tree old0
, new0
, old1
, new1
; tree type
= TREE_TYPE (arg
); enum tree_code code
= TREE_CODE (arg
);
char class = TREE_CODE_CLASS (code
);
/* We can handle some of the 'e' cases here. */
if (class == 'e' && code
== TRUTH_NOT_EXPR
)
&& (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
return fold (build1 (code
, type
,
eval_subst (TREE_OPERAND (arg
, 0),
old0
, new0
, old1
, new1
))); return fold (build (code
, type
,
eval_subst (TREE_OPERAND (arg
, 0),
eval_subst (TREE_OPERAND (arg
, 1),
old0
, new0
, old1
, new1
))); return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
return fold (build (code
, type
,
eval_subst (TREE_OPERAND (arg
, 0),
eval_subst (TREE_OPERAND (arg
, 1),
eval_subst (TREE_OPERAND (arg
, 2),
old0
, new0
, old1
, new1
))); tree arg0
= TREE_OPERAND (arg
, 0); tree arg1
= TREE_OPERAND (arg
, 1); /* We need to check both for exact equality and tree equality. The
former will be true if the operand has a side-effect. In that
case, we know the operand occurred exactly once. */
if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
return fold (build (code
, type
, arg0
, arg1
));
/* Return a tree for the case when the result of an expression is RESULT
converted to TYPE and OMITTED was previously an operand of the expression
but is now not needed (e.g., we folded OMITTED * 0).
If OMITTED has side effects, we must evaluate it. Otherwise, just do
the conversion of RESULT to TYPE. */
omit_one_operand (type
, result
, omitted
)
tree type
, result
, omitted
; tree t
= convert (type
, result
); if (TREE_SIDE_EFFECTS (omitted
))
return build (COMPOUND_EXPR
, type
, omitted
, t
);
/* Return a simplified tree node for the truth-negation of ARG. This
never alters ARG itself. We assume that ARG is an operation that
returns a truth value (0 or 1). */
tree type
= TREE_TYPE (arg
); enum tree_code code
= TREE_CODE (arg
);
/* If this is a comparison, we can simply invert it, except for
floating-point non-equality comparisons, in which case we just
enclose a TRUTH_NOT_EXPR around what we have. */
if (TREE_CODE_CLASS (code
) == '<')
if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
&& code
!= NE_EXPR
&& code
!= EQ_EXPR
)
return build1 (TRUTH_NOT_EXPR
, type
, arg
);
return build (invert_tree_comparison (code
), type
,
TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
return convert (type
, build_int_2 (TREE_INT_CST_LOW (arg
) == 0
&& TREE_INT_CST_HIGH (arg
) == 0, 0));
return build (TRUTH_OR_EXPR
, type
,
invert_truthvalue (TREE_OPERAND (arg
, 0)),
invert_truthvalue (TREE_OPERAND (arg
, 1)));
return build (TRUTH_AND_EXPR
, type
,
invert_truthvalue (TREE_OPERAND (arg
, 0)),
invert_truthvalue (TREE_OPERAND (arg
, 1)));
/* Here we can invert either operand. We invert the first operand
unless the second operand is a TRUTH_NOT_EXPR in which case our
result is the XOR of the first operand with the inside of the
negation of the second operand. */
if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
return build (TRUTH_XOR_EXPR
, type
,
invert_truthvalue (TREE_OPERAND (arg
, 0)),
return build (TRUTH_ORIF_EXPR
, type
,
invert_truthvalue (TREE_OPERAND (arg
, 0)),
invert_truthvalue (TREE_OPERAND (arg
, 1)));
return build (TRUTH_ANDIF_EXPR
, type
,
invert_truthvalue (TREE_OPERAND (arg
, 0)),
invert_truthvalue (TREE_OPERAND (arg
, 1)));
return TREE_OPERAND (arg
, 0);
return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
invert_truthvalue (TREE_OPERAND (arg
, 1)),
invert_truthvalue (TREE_OPERAND (arg
, 2)));
return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
invert_truthvalue (TREE_OPERAND (arg
, 1)));
return invert_truthvalue (TREE_OPERAND (arg
, 0));
return build1 (TREE_CODE (arg
), type
,
invert_truthvalue (TREE_OPERAND (arg
, 0)));
if (! integer_onep (TREE_OPERAND (arg
, 1)))
return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
operands are another bit-wise operation with a common input. If so,
distribute the bit operations to save an operation and possibly two if
constants are involved. For example, convert
(A | B) & (A | C) into A | (B & C)
Further simplification will occur if B and C are constants.
If this optimization cannot be done, 0 will be returned. */
distribute_bit_expr (code
, type
, arg0
, arg1
)
if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
|| TREE_CODE (arg0
) == code
|| (TREE_CODE (arg0
) != BIT_AND_EXPR
&& TREE_CODE (arg0
) != BIT_IOR_EXPR
))
if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
common
= TREE_OPERAND (arg0
, 0); left
= TREE_OPERAND (arg0
, 1); right
= TREE_OPERAND (arg1
, 1); else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
common
= TREE_OPERAND (arg0
, 0); left
= TREE_OPERAND (arg0
, 1); right
= TREE_OPERAND (arg1
, 0); else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
common
= TREE_OPERAND (arg0
, 1); left
= TREE_OPERAND (arg0
, 0); right
= TREE_OPERAND (arg1
, 1); else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
common
= TREE_OPERAND (arg0
, 1); left
= TREE_OPERAND (arg0
, 0); right
= TREE_OPERAND (arg1
, 0); return fold (build (TREE_CODE (arg0
), type
, common
,
fold (build (code
, type
, left
, right
))));
/* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
tree result
= build (BIT_FIELD_REF
, type
, inner
, size_int (bitsize
), size_int (bitpos
));
TREE_UNSIGNED (result
) = unsignedp
;
/* Optimize a bit-field compare.
There are two cases: First is a compare against a constant and the
second is a comparison of two items where the fields are at the same
bit position relative to the start of a chunk (byte, halfword, word)
large enough to contain it. In these cases we can avoid the shift
implicit in bitfield extractions.
For constants, we emit a compare of the shifted constant with the
BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
compared. For two fields at the same position, we do the ANDs with the
similar mask and compare the result of the ANDs.
CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
COMPARE_TYPE is the type of the comparison, and LHS and RHS
are the left and right operands of the comparison, respectively.
If the optimization described above can be done, we return the resulting
tree. Otherwise we return zero. */
optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
int lbitpos
, lbitsize
, rbitpos
, rbitsize
;
int lnbitpos
, lnbitsize
, rnbitpos
, rnbitsize
;
tree type
= TREE_TYPE (lhs
); tree signed_type
, unsigned_type
; int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
enum machine_mode lmode
, rmode
, lnmode
, rnmode
;
int lunsignedp
, runsignedp
;
int lvolatilep
= 0, rvolatilep
= 0;
/* Get all the information about the extractions being done. If the bit size
if the same as the size of the underlying object, we aren't doing an
extraction at all and so can do nothing. */
linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
, &lunsignedp
, &lvolatilep
);
if (lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
/* If this is not a constant, we can only do something if bit positions,
sizes, and signedness are the same. */
rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
, &runsignedp
, &rvolatilep
);
if (lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
|| lunsignedp
!= runsignedp
|| offset
!= 0)
/* See if we can find a mode to refer to this field. We should be able to,
lnmode
= get_best_mode (lbitsize
, lbitpos
, TYPE_ALIGN (TREE_TYPE (linner
)), word_mode
,
/* Set signed and unsigned types of the precision of this mode for the
signed_type
= type_for_mode (lnmode
, 0); unsigned_type
= type_for_mode (lnmode
, 1); rnmode
= get_best_mode (rbitsize
, rbitpos
, TYPE_ALIGN (TREE_TYPE (rinner
)), word_mode
,
/* Compute the bit position and size for the new reference and our offset
within it. If the new reference is the same size as the original, we
won't optimize anything, so return zero. */
lnbitsize
= GET_MODE_BITSIZE (lnmode
); lnbitpos
= lbitpos
& ~ (lnbitsize
- 1); if (lnbitsize
== lbitsize
)
rnbitsize
= GET_MODE_BITSIZE (rnmode
); rnbitpos
= rbitpos
& ~ (rnbitsize
- 1); if (rnbitsize
== rbitsize
)
lbitpos
= lnbitsize
- lbitsize
- lbitpos
; /* Make the mask to be used against the extracted field. */
mask
= build_int_2 (~0, ~0); TREE_TYPE (mask
) = unsigned_type
;
force_fit_type (mask
, 0);
mask
= convert (unsigned_type
, mask
); mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (lnbitsize
- lbitsize
), 0); mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (lnbitsize
- lbitsize
- lbitpos
), 0);
/* If not comparing with constant, just rework the comparison
return build (code
, compare_type
,
build (BIT_AND_EXPR
, unsigned_type
,
make_bit_field_ref (linner
, unsigned_type
,
build (BIT_AND_EXPR
, unsigned_type
,
make_bit_field_ref (rinner
, unsigned_type
,
/* Otherwise, we are handling the constant case. See if the constant is too
big for the field. Warn and return a tree of for 0 (false) if so. We do
this not only for its own sake, but to avoid having to test for this
error case below. If we didn't, we might generate wrong code.
For unsigned fields, the constant shifted right by the field length should
be all zero. For signed fields, the high-order bits should agree with
if (! integer_zerop (const_binop (RSHIFT_EXPR
,
convert (unsigned_type
, rhs
),
size_int (lbitsize
), 0)))
warning ("comparison is always %s due to width of bitfield",
code
== NE_EXPR
? "one" : "zero"); return convert (compare_type
,
? integer_one_node
: integer_zero_node
));
tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
), size_int (lbitsize
- 1), 0);
if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
warning ("comparison is always %s due to width of bitfield",
code
== NE_EXPR
? "one" : "zero"); return convert (compare_type
,
? integer_one_node
: integer_zero_node
));
/* Single-bit compares should always be against zero. */
if (lbitsize
== 1 && ! integer_zerop (rhs
))
code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
; rhs
= convert (type
, integer_zero_node
); /* Make a new bitfield reference, shift the constant over the
appropriate number of bits and mask it with the computed mask
(in case this was a signed field). If we changed it, make a new one. */
lhs
= make_bit_field_ref (linner
, unsigned_type
, lnbitsize
, lnbitpos
, 1); rhs
= fold (const_binop (BIT_AND_EXPR
, const_binop (LSHIFT_EXPR
,
convert (unsigned_type
, rhs
),
return build (code
, compare_type
,
build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
/* Subroutine for fold_truthop: decode a field reference.
If EXP is a comparison reference, we return the innermost reference.
*PBITSIZE is set to the number of bits in the reference, *PBITPOS is
set to the starting bit number.
If the innermost field can be completely contained in a mode-sized
unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
*PVOLATILEP is set to 1 if the any expression encountered is volatile;
otherwise it is not changed.
*PUNSIGNEDP is set to the signedness of the field.
*PMASK is set to the mask used. This is either contained in a
BIT_AND_EXPR or derived from the width of the field.
Return 0 if this is not a component reference or is one that we can't
decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
enum machine_mode
*pmode
;
int *punsignedp
, *pvolatilep
;
/* All the optimizations using this function assume integer fields.
There are problems with FP fields since the type_for_size call
below can fail for, e.g., XFmode. */
if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
if (TREE_CODE (exp
) == BIT_AND_EXPR
)
mask
= TREE_OPERAND (exp
, 1); exp
= TREE_OPERAND (exp
, 0); STRIP_NOPS (exp
); STRIP_NOPS (mask
);
if (TREE_CODE (mask
) != INTEGER_CST
)
if (TREE_CODE (exp
) != COMPONENT_REF
&& TREE_CODE (exp
) != ARRAY_REF
&& TREE_CODE (exp
) != BIT_FIELD_REF
)
inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
, if (*pbitsize
< 0 || offset
!= 0)
tree unsigned_type
= type_for_size (*pbitsize
, 1); int precision
= TYPE_PRECISION (unsigned_type
);
mask
= build_int_2 (~0, ~0); TREE_TYPE (mask
) = unsigned_type
;
force_fit_type (mask
, 0);
mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0); mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);/* Return non-zero if MASK represents a mask of SIZE ones in the low-order
all_ones_mask_p (mask
, size
)
tree type
= TREE_TYPE (mask
); int precision
= TYPE_PRECISION (type
);
tmask
= build_int_2 (~0, ~0); TREE_TYPE (tmask
) = signed_type (type
);
force_fit_type (tmask
, 0);
const_binop (RSHIFT_EXPR
,
const_binop (LSHIFT_EXPR
, tmask
,
size_int (precision
- size
), 0),
size_int (precision
- size
), 0),
/* Subroutine for fold_truthop: determine if an operand is simple enough
to be evaluated unconditionally. */
/* Strip any conversions that don't change the machine mode. */
while ((TREE_CODE (exp
) == NOP_EXPR
|| TREE_CODE (exp
) == CONVERT_EXPR
)
&& (TYPE_MODE (TREE_TYPE (exp
))
== TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
exp
= TREE_OPERAND (exp
, 0); return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
|| (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'd'
&& ! TREE_ADDRESSABLE (exp
)
&& ! TREE_THIS_VOLATILE (exp
)
/* Don't regard global variables as simple. They may be
allocated in ways unknown to the compiler (shared memory,
/* Loading a static variable is unduly expensive, but global
registers aren't expensive. */
&& (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
/* Subroutine for fold_truthop: try to optimize a range test.
For example, "i >= 2 && i =< 9" can be done as "(unsigned) (i - 2) <= 7".
JCODE is the logical combination of the two terms. It is TRUTH_AND_EXPR
(representing TRUTH_ANDIF_EXPR and TRUTH_AND_EXPR) or TRUTH_OR_EXPR
(representing TRUTH_ORIF_EXPR and TRUTH_OR_EXPR). TYPE is the type of
VAR is the value being tested. LO_CODE and HI_CODE are the comparison
operators comparing VAR to LO_CST and HI_CST. LO_CST is known to be no
larger than HI_CST (they may be equal).
We return the simplified tree or 0 if no optimization is possible. */
range_test (jcode
, type
, lo_code
, hi_code
, var
, lo_cst
, hi_cst
)
enum tree_code jcode
, lo_code
, hi_code
;
tree type
, var
, lo_cst
, hi_cst
; /* See if this is a range test and normalize the constant terms. */
if (jcode
== TRUTH_AND_EXPR
)
/* See if we have VAR != CST && VAR != CST+1. */
if (! (hi_code
== NE_EXPR
&& TREE_INT_CST_LOW (hi_cst
) - TREE_INT_CST_LOW (lo_cst
) == 1
&& tree_int_cst_equal (integer_one_node
,
hi_cst
= const_binop (MINUS_EXPR
, hi_cst
, integer_one_node
, 0); else if (hi_code
!= LE_EXPR
)
lo_cst
= const_binop (PLUS_EXPR
, lo_cst
, integer_one_node
, 0); /* We now have VAR >= LO_CST && VAR <= HI_CST. */
/* See if we have VAR == CST || VAR == CST+1. */
if (! (hi_code
== EQ_EXPR
&& TREE_INT_CST_LOW (hi_cst
) - TREE_INT_CST_LOW (lo_cst
) == 1
&& tree_int_cst_equal (integer_one_node
,
hi_cst
= const_binop (MINUS_EXPR
, hi_cst
, integer_one_node
, 0); else if (hi_code
!= GT_EXPR
)
lo_cst
= const_binop (PLUS_EXPR
, lo_cst
, integer_one_node
, 0); /* We now have VAR < LO_CST || VAR > HI_CST. */
/* When normalizing, it is possible to both increment the smaller constant
and decrement the larger constant. See if they are still ordered. */
if (tree_int_cst_lt (hi_cst
, lo_cst
))
/* Fail if VAR isn't an integer. */
if (! INTEGRAL_TYPE_P (utype
))
/* The range test is invalid if subtracting the two constants results
in overflow. This can happen in traditional mode. */
if (! int_fits_type_p (hi_cst
, TREE_TYPE (var
))
|| ! int_fits_type_p (lo_cst
, TREE_TYPE (var
)))
if (! TREE_UNSIGNED (utype
))
utype
= unsigned_type (utype
); var
= convert (utype
, var
); lo_cst
= convert (utype
, lo_cst
); hi_cst
= convert (utype
, hi_cst
); return fold (convert (type
,
build (MINUS_EXPR
, utype
, var
, lo_cst
),
const_binop (MINUS_EXPR
, hi_cst
, lo_cst
, 0))));
/* Find ways of folding logical expressions of LHS and RHS:
Try to merge two comparisons to the same innermost item.
Look for range tests like "ch >= '0' && ch <= '9'".
Look for combinations of simple terms on machines with expensive branches
and evaluate the RHS unconditionally.
For example, if we have p->a == 2 && p->b == 4 and we can make an
object large enough to span both A and B, we can do this with a comparison
against the object ANDed with the a mask.
If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
operations to do this with one comparison.
We check for both normal comparisons and the BIT_AND_EXPRs made this by
function and the one above.
CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
We return the simplified tree or 0 if no optimization is possible. */
fold_truthop (code
, truth_type
, lhs
, rhs
)
tree truth_type
, lhs
, rhs
; /* If this is the "or" of two comparisons, we can do something if we
the comparisons are NE_EXPR. If this is the "and", we can do something
if the comparisons are EQ_EXPR. I.e.,
(a->b == 2 && a->c == 4) can become (a->new == NEW).
WANTED_CODE is this operation code. For single bit fields, we can
convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
comparison for one-bit fields. */
enum tree_code wanted_code
;
enum tree_code lcode
, rcode
;
tree ll_arg
, lr_arg
, rl_arg
, rr_arg
; tree ll_inner
, lr_inner
, rl_inner
, rr_inner
; int ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
int rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
int xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
int lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
enum machine_mode lnmode
, rnmode
;
tree ll_mask
, lr_mask
, rl_mask
, rr_mask
; /* Start by getting the comparison codes and seeing if this looks like
a range test. Fail if anything is volatile. */
if (TREE_SIDE_EFFECTS (lhs
)
|| TREE_SIDE_EFFECTS (rhs
))
if (TREE_CODE_CLASS (lcode
) != '<'
|| TREE_CODE_CLASS (rcode
) != '<')
code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
) ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
ll_arg
= TREE_OPERAND (lhs
, 0); lr_arg
= TREE_OPERAND (lhs
, 1); rl_arg
= TREE_OPERAND (rhs
, 0); rr_arg
= TREE_OPERAND (rhs
, 1); if (TREE_CODE (lr_arg
) == INTEGER_CST
&& TREE_CODE (rr_arg
) == INTEGER_CST
&& operand_equal_p (ll_arg
, rl_arg
, 0))
if (tree_int_cst_lt (lr_arg
, rr_arg
))
result
= range_test (code
, truth_type
, lcode
, rcode
, result
= range_test (code
, truth_type
, rcode
, lcode
, /* If this isn't a range test, it also isn't a comparison that
can be merged. However, it wins to evaluate the RHS unconditionally
on machines with expensive branches. */
if (result
== 0 && BRANCH_COST
>= 2)
if (TREE_CODE (ll_arg
) != VAR_DECL
&& TREE_CODE (ll_arg
) != PARM_DECL
)
/* Avoid evaluating the variable part twice. */
ll_arg
= save_expr (ll_arg
); lhs
= build (lcode
, TREE_TYPE (lhs
), ll_arg
, lr_arg
); rhs
= build (rcode
, TREE_TYPE (rhs
), ll_arg
, rr_arg
); return build (code
, truth_type
, lhs
, rhs
);
/* If the RHS can be evaluated unconditionally and its operands are
simple, it wins to evaluate the RHS unconditionally on machines
with expensive branches. In this case, this isn't a comparison
/* @@ I'm not sure it wins on the m88110 to do this if the comparisons
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs
))
&& simple_operand_p (rl_arg
)
&& simple_operand_p (rr_arg
))
return build (code
, truth_type
, lhs
, rhs
);
/* See if the comparisons can be merged. Then get all the parameters for
if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
|| (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
ll_inner
= decode_field_reference (ll_arg
, &ll_bitsize
, &ll_bitpos
, &ll_mode
,
&ll_unsignedp
, &volatilep
, &ll_mask
);
lr_inner
= decode_field_reference (lr_arg
, &lr_bitsize
, &lr_bitpos
, &lr_mode
,
&lr_unsignedp
, &volatilep
, &lr_mask
);
rl_inner
= decode_field_reference (rl_arg
, &rl_bitsize
, &rl_bitpos
, &rl_mode
,
&rl_unsignedp
, &volatilep
, &rl_mask
);
rr_inner
= decode_field_reference (rr_arg
, &rr_bitsize
, &rr_bitpos
, &rr_mode
,
&rr_unsignedp
, &volatilep
, &rr_mask
);
/* It must be true that the inner operation on the lhs of each
comparison must be the same if we are to be able to do anything.
Then see if we have constants. If not, the same must be true for
if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
|| ! operand_equal_p (ll_inner
, rl_inner
, 0))
if (TREE_CODE (lr_arg
) == INTEGER_CST
&& TREE_CODE (rr_arg
) == INTEGER_CST
)
l_const
= lr_arg
, r_const
= rr_arg
; else if (lr_inner
== 0 || rr_inner
== 0
|| ! operand_equal_p (lr_inner
, rr_inner
, 0))
/* If either comparison code is not correct for our logical operation,
fail. However, we can convert a one-bit comparison against zero into
the opposite comparison against that bit being set in the field. */
wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
); if (lcode
!= wanted_code
)
if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
if (rcode
!= wanted_code
)
if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
/* See if we can find a mode that contains both fields being compared on
the left. If we can't, fail. Otherwise, update all constants and masks
to be relative to a field of that size. */
first_bit
= MIN (ll_bitpos
, rl_bitpos
); end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
); lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
, TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
lnbitsize
= GET_MODE_BITSIZE (lnmode
); lnbitpos
= first_bit
& ~ (lnbitsize
- 1); type
= type_for_size (lnbitsize
, 1); xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
; xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
; xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
; ll_mask
= const_binop (LSHIFT_EXPR
, convert (type
, ll_mask
), size_int (xll_bitpos
), 0);
rl_mask
= const_binop (LSHIFT_EXPR
, convert (type
, rl_mask
), size_int (xrl_bitpos
), 0);
/* Make sure the constants are interpreted as unsigned, so we
don't have sign bits outside the range of their type. */
l_const
= convert (unsigned_type (TREE_TYPE (l_const
)), l_const
); l_const
= const_binop (LSHIFT_EXPR
, convert (type
, l_const
), size_int (xll_bitpos
), 0);
r_const
= convert (unsigned_type (TREE_TYPE (r_const
)), r_const
); r_const
= const_binop (LSHIFT_EXPR
, convert (type
, r_const
), size_int (xrl_bitpos
), 0);
/* If the right sides are not constant, do the same for it. Also,
disallow this optimization if a size or signedness mismatch occurs
between the left and right sides. */
if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
|| ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
/* Make sure the two fields on the right
correspond to the left without being swapped. */
|| ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
first_bit
= MIN (lr_bitpos
, rr_bitpos
); end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
); rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
, TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
rnbitsize
= GET_MODE_BITSIZE (rnmode
); rnbitpos
= first_bit
& ~ (rnbitsize
- 1); xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
; xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
; xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
; lr_mask
= const_binop (LSHIFT_EXPR
, convert (type
, lr_mask
), size_int (xlr_bitpos
), 0);
rr_mask
= const_binop (LSHIFT_EXPR
, convert (type
, rr_mask
), size_int (xrr_bitpos
), 0);
/* Make a mask that corresponds to both fields being compared.
Do this for both items being compared. If the masks agree,
we can do this by masking both and comparing the masked
ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0); lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0); if (operand_equal_p (ll_mask
, lr_mask
, 0) && lnbitsize
== rnbitsize
)
lhs
= make_bit_field_ref (ll_inner
, type
, lnbitsize
, lnbitpos
, ll_unsignedp
|| rl_unsignedp
); rhs
= make_bit_field_ref (lr_inner
, type
, rnbitsize
, rnbitpos
, lr_unsignedp
|| rr_unsignedp
); if (! all_ones_mask_p (ll_mask
, lnbitsize
))
lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
); rhs
= build (BIT_AND_EXPR
, type
, rhs
, ll_mask
); return build (wanted_code
, truth_type
, lhs
, rhs
);
/* There is still another way we can do something: If both pairs of
fields being compared are adjacent, we may be able to make a wider
field containing them both. */
if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
&& lr_bitsize
+ lr_bitpos
== rr_bitpos
)
|| (ll_bitpos
== rl_bitpos
+ rl_bitsize
&& lr_bitpos
== rr_bitpos
+ rr_bitsize
))
return build (wanted_code
, truth_type
,
make_bit_field_ref (ll_inner
, type
,
MIN (ll_bitpos
, rl_bitpos
),
make_bit_field_ref (lr_inner
, type
,
MIN (lr_bitpos
, rr_bitpos
),
/* Handle the case of comparisons with constants. If there is something in
common between the masks, those bits of the constants must be the same.
If not, the condition is always false. Test for this to avoid generating
result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0); if (! integer_zerop (result
)
&& simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
if (wanted_code
== NE_EXPR
)
warning ("`or' of unmatched not-equal tests is always 1");
return convert (truth_type
, integer_one_node
);
warning ("`and' of mutually exclusive equal-tests is always zero");
return convert (truth_type
, integer_zero_node
);
/* Construct the expression we will return. First get the component
reference we will make. Unless the mask is all ones the width of
that field, perform the mask operation. Then compare with the
result
= make_bit_field_ref (ll_inner
, type
, lnbitsize
, lnbitpos
, ll_unsignedp
|| rl_unsignedp
); ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0); if (! all_ones_mask_p (ll_mask
, lnbitsize
))
result
= build (BIT_AND_EXPR
, type
, result
, ll_mask
); return build (wanted_code
, truth_type
, result
,
const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
/* Perform constant folding and related simplification of EXPR.
The related simplifications include x*1 => x, x*0 => 0, etc.,
and application of the associative law.
NOP_EXPR conversions may be removed freely (as long as we
are careful not to change the C type of the overall expression)
We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
but we can constant-fold them if they have constant operands. */
tree type
= TREE_TYPE (expr
); register tree arg0
, arg1
;
register enum tree_code code
= TREE_CODE (t
);
/* WINS will be nonzero when the switch is done
if all operands are constant. */
/* Return right away if already constant. */
kind
= TREE_CODE_CLASS (code
); if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
/* Special case for conversion ops that can have fixed point args. */
arg0
= TREE_OPERAND (t
, 0); /* Don't use STRIP_NOPS, because signedness of argument type matters. */
if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
subop
= TREE_REALPART (arg0
); if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
&& TREE_CODE (subop
) != REAL_CST
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
/* Note that TREE_CONSTANT isn't enough:
static var addresses are constant but we can't
do arithmetic on them. */
else if (kind
== 'e' || kind
== '<'
|| kind
== '1' || kind
== '2' || kind
== 'r')
register int len
= tree_code_length
[(int) code
];
for (i
= 0; i
< len
; i
++)
tree op
= TREE_OPERAND (t
, i
); continue; /* Valid for CALL_EXPR, at least. */
if (kind
== '<' || code
== RSHIFT_EXPR
)
/* Signedness matters here. Perhaps we can refine this
/* Strip any conversions that don't change the mode. */
if (TREE_CODE (op
) == COMPLEX_CST
)
subop
= TREE_REALPART (op
); if (TREE_CODE (subop
) != INTEGER_CST
#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
&& TREE_CODE (subop
) != REAL_CST
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
/* Note that TREE_CONSTANT isn't enough:
static var addresses are constant but we can't
do arithmetic on them. */
/* If this is a commutative operation, and ARG0 is a constant, move it
to ARG1 to reduce the number of tests below. */
if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
|| code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
&& (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
tem
= arg0
; arg0
= arg1
; arg1
= tem
; tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1); TREE_OPERAND (t
, 1) = tem
;
/* Now WINS is set as described above,
ARG0 is the first operand of EXPR,
and ARG1 is the second operand (if it has more than one operand).
First check for cases where an arithmetic operation is applied to a
compound, conditional, or comparison operation. Push the arithmetic
operation inside the compound or conditional to see if any folding
can then be done. Convert comparison to conditional for this purpose.
The also optimizes non-constant cases that used to be done in
if (TREE_CODE_CLASS (code
) == '1')
if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
else if (TREE_CODE (arg0
) == COND_EXPR
)
t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0), fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))),
fold (build1 (code
, type
, TREE_OPERAND (arg0
, 2)))));
/* If this was a conversion, and all we did was to move into
inside the COND_EXPR, bring it back out. Then return so we
don't get into an infinite recursion loop taking the conversion
if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
|| code
== NON_LVALUE_EXPR
)
&& TREE_CODE (t
) == COND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 1)) == code
&& TREE_CODE (TREE_OPERAND (t
, 2)) == code
&& (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
== TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0))))
TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0)),
TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
return fold (build (COND_EXPR
, type
, arg0
,
fold (build1 (code
, type
, integer_one_node
)),
fold (build1 (code
, type
, integer_zero_node
))));
else if (TREE_CODE_CLASS (code
) == '2')
if (TREE_CODE (arg1
) == COMPOUND_EXPR
)
return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
else if (TREE_CODE (arg1
) == COND_EXPR
|| TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<')
tree test
, true_value
, false_value
; if (TREE_CODE (arg1
) == COND_EXPR
)
test
= TREE_OPERAND (arg1
, 0); true_value
= TREE_OPERAND (arg1
, 1); false_value
= TREE_OPERAND (arg1
, 2); true_value
= integer_one_node
; false_value
= integer_zero_node
; if (TREE_CODE (arg0
) != VAR_DECL
&& TREE_CODE (arg0
) != PARM_DECL
)
test
= fold (build (COND_EXPR
, type
, test
, fold (build (code
, type
, arg0
, true_value
)),
fold (build (code
, type
, arg0
, false_value
))));
if (TREE_CODE (arg0
) == SAVE_EXPR
)
return build (COMPOUND_EXPR
, type
,
convert (void_type_node
, arg0
), test
);
return convert (type
, test
);
else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
else if (TREE_CODE (arg0
) == COND_EXPR
|| TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
tree test
, true_value
, false_value
; if (TREE_CODE (arg0
) == COND_EXPR
)
test
= TREE_OPERAND (arg0
, 0); true_value
= TREE_OPERAND (arg0
, 1); false_value
= TREE_OPERAND (arg0
, 2); true_value
= integer_one_node
; false_value
= integer_zero_node
; if (TREE_CODE (arg1
) != VAR_DECL
&& TREE_CODE (arg1
) != PARM_DECL
)
test
= fold (build (COND_EXPR
, type
, test
, fold (build (code
, type
, true_value
, arg1
)),
fold (build (code
, type
, false_value
, arg1
))));
if (TREE_CODE (arg1
) == SAVE_EXPR
)
return build (COMPOUND_EXPR
, type
,
convert (void_type_node
, arg1
), test
);
return convert (type
, test
);
else if (TREE_CODE_CLASS (code
) == '<'
&& TREE_CODE (arg0
) == COMPOUND_EXPR
)
return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
else if (TREE_CODE_CLASS (code
) == '<'
&& TREE_CODE (arg1
) == COMPOUND_EXPR
)
return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
return fold (DECL_INITIAL (t
));
/* Other kinds of FIX are not handled properly by fold_convert. */
/* Two conversions in a row are not needed unless:
- the intermediate type is narrower than both initial and final, or
- the intermediate type and innermost type differ in signedness,
and the outermost type is wider than the intermediate, or
- the initial type is a pointer type and the precisions of the
intermediate and final types differ, or
- the final type is a pointer type and the precisions of the
initial and intermediate types differ. */
if ((TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
|| TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
&& (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0)))
> TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))
TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0)))
> TYPE_PRECISION (TREE_TYPE (t
)))
&& ! ((TREE_CODE (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))
&& (TREE_CODE (TREE_TYPE (TREE_OPERAND (t
, 0)))
&& (TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (t
, 0)))
!= TREE_UNSIGNED (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))
&& (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0)))
< TYPE_PRECISION (TREE_TYPE (t
))))
&& ((TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (t
, 0)))
&& (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0)))
> TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))))
(TREE_UNSIGNED (TREE_TYPE (t
))
&& (TYPE_PRECISION (TREE_TYPE (t
))
> TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0))))))
&& ! ((TREE_CODE (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))
&& (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0)))
!= TYPE_PRECISION (TREE_TYPE (t
))))
&& ! (TREE_CODE (TREE_TYPE (t
)) == POINTER_TYPE
&& (TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)))
!= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (t
, 0))))))
return convert (TREE_TYPE (t
), TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
&& TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
/* Detect assigning a bitfield. */
&& !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
&& DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
/* Don't leave an assignment inside a conversion
unless assigning a bitfield. */
tree prev
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
/* First do the assignment, then return converted constant. */
t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
)); TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
return fold_convert (t
, arg0
);
#if 0 /* This loses on &"foo"[0]. */
/* Fold an expression like: "foo"[2] */
if (TREE_CODE (arg0
) == STRING_CST
&& TREE_CODE (arg1
) == INTEGER_CST
&& !TREE_INT_CST_HIGH (arg1
)
&& (i
= TREE_INT_CST_LOW (arg1
)) < TREE_STRING_LENGTH (arg0
))
t
= build_int_2 (TREE_STRING_POINTER (arg0
)[i
], 0); TREE_TYPE (t
) = TREE_TYPE (TREE_TYPE (arg0
));
TREE_CONSTANT (t
) = wins
;
if (TREE_CODE (arg0
) == INTEGER_CST
)
int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
TREE_INT_CST_HIGH (arg0
),
t
= build_int_2 (low
, high
); TREE_CONSTANT_OVERFLOW (t
)
= (TREE_CONSTANT_OVERFLOW (arg0
)
| force_fit_type (t
, overflow
));
else if (TREE_CODE (arg0
) == REAL_CST
)
t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
))); else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
return TREE_OPERAND (arg0
, 0);
/* Convert - (a - b) to (b - a) for non-floating-point. */
else if (TREE_CODE (arg0
) == MINUS_EXPR
&& ! FLOAT_TYPE_P (type
))
return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
if (TREE_CODE (arg0
) == INTEGER_CST
)
if (! TREE_UNSIGNED (type
)
&& TREE_INT_CST_HIGH (arg0
) < 0)
int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
TREE_INT_CST_HIGH (arg0
),
t
= build_int_2 (low
, high
); TREE_CONSTANT_OVERFLOW (t
)
= (TREE_CONSTANT_OVERFLOW (arg0
)
| force_fit_type (t
, overflow
));
else if (TREE_CODE (arg0
) == REAL_CST
)
if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
else if (TREE_CODE (arg0
) == ABS_EXPR
|| TREE_CODE (arg0
) == NEGATE_EXPR
)
return build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
if (TREE_CODE (arg0
) == INTEGER_CST
)
t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
), ~ TREE_INT_CST_HIGH (arg0
));
TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
return TREE_OPERAND (arg0
, 0);
if (TREE_CODE (arg1
) == NEGATE_EXPR
)
return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
else if (! FLOAT_TYPE_P (type
))
if (integer_zerop (arg1
))
return non_lvalue (convert (type
, arg0
));
/* If we are adding two BIT_AND_EXPR's, both of which are and'ing
with a constant, and the two constants have no bits in common,
we should treat this as a BIT_IOR_EXPR since this may produce more
if (TREE_CODE (arg0
) == BIT_AND_EXPR
&& TREE_CODE (arg1
) == BIT_AND_EXPR
&& TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
&& integer_zerop (const_binop (BIT_AND_EXPR
,
TREE_OPERAND (arg1
, 1), 0)))
/* In IEEE floating point, x+0 may not equal x. */
else if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
return non_lvalue (convert (type
, arg0
));
/* In most languages, can't associate operations on floats
through parentheses. Rather than remember where the parentheses
were, we don't associate floats at all. It shouldn't matter much. */
/* The varsign == -1 cases happen only for addition and subtraction.
It says that the arg that was split was really CON minus VAR.
The rest of the code applies to all associative operations. */
if (split_tree (arg0
, code
, &var
, &con
, &varsign
))
/* EXPR is (CON-VAR) +- ARG1. */
/* If it is + and VAR==ARG1, return just CONST. */
if (code
== PLUS_EXPR
&& operand_equal_p (var
, arg1
, 0))
return convert (TREE_TYPE (t
), con
);
/* If ARG0 is a constant, don't change things around;
instead keep all the constant computations together. */
if (TREE_CONSTANT (arg0
))
/* Otherwise return (CON +- ARG1) - VAR. */
TREE_SET_CODE (t
, MINUS_EXPR
);
TREE_OPERAND (t
, 1) = var
;
= fold (build (code
, TREE_TYPE (t
), con
, arg1
));
/* EXPR is (VAR+CON) +- ARG1. */
/* If it is - and VAR==ARG1, return just CONST. */
if (code
== MINUS_EXPR
&& operand_equal_p (var
, arg1
, 0))
return convert (TREE_TYPE (t
), con
);
/* If ARG0 is a constant, don't change things around;
instead keep all the constant computations together. */
if (TREE_CONSTANT (arg0
))
/* Otherwise return VAR +- (ARG1 +- CON). */
TREE_OPERAND (t
, 1) = tem
= fold (build (code
, TREE_TYPE (t
), arg1
, con
));
TREE_OPERAND (t
, 0) = var
;
&& (code
== PLUS_EXPR
|| code
== MINUS_EXPR
))
return convert (type
, var
);
/* If we have x +/- (c - d) [c an explicit integer]
change it to x -/+ (d - c) since if d is relocatable
then the latter can be a single immediate insn
and the former cannot. */
if (TREE_CODE (tem
) == MINUS_EXPR
&& TREE_CODE (TREE_OPERAND (tem
, 0)) == INTEGER_CST
)
tree tem1
= TREE_OPERAND (tem
, 1); TREE_OPERAND (tem
, 1) = TREE_OPERAND (tem
, 0);
TREE_OPERAND (tem
, 0) = tem1
;
(code
== PLUS_EXPR
? MINUS_EXPR
: PLUS_EXPR
));
if (split_tree (arg1
, code
, &var
, &con
, &varsign
))
/* EXPR is ARG0 +- (CON +- VAR). */
if (TREE_CODE (t
) == MINUS_EXPR
&& operand_equal_p (var
, arg0
, 0))
/* If VAR and ARG0 cancel, return just CON or -CON. */
return convert (TREE_TYPE (t
), con
);
return fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
),
convert (TREE_TYPE (t
), con
)));
if (TREE_CONSTANT (arg1
))
(code
== PLUS_EXPR
? MINUS_EXPR
: PLUS_EXPR
));
= fold (build (code
, TREE_TYPE (t
), arg0
, con
));
TREE_OPERAND (t
, 1) = var
;
if (integer_zerop (TREE_OPERAND (t
, 0))
&& TREE_CODE (t
) == PLUS_EXPR
)
return convert (TREE_TYPE (t
), var
);
#if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1
) == REAL_CST
)
#endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
t1
= const_binop (code
, arg0
, arg1
, 0); /* The return value should always have
the same type as the original expression. */
TREE_TYPE (t1
) = TREE_TYPE (t
);
if (! FLOAT_TYPE_P (type
))
if (! wins
&& integer_zerop (arg0
))
return build1 (NEGATE_EXPR
, type
, arg1
);
if (integer_zerop (arg1
))
return non_lvalue (convert (type
, arg0
));
/* Convert A - (-B) to A + B. */
else if (TREE_CODE (arg1
) == NEGATE_EXPR
)
return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
else if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
)
/* Except with IEEE floating point, 0-x equals -x. */
if (! wins
&& real_zerop (arg0
))
return build1 (NEGATE_EXPR
, type
, arg1
);
/* Except with IEEE floating point, x-0 equals x. */
return non_lvalue (convert (type
, arg0
));
/* Fold &x - &x. This can happen from &x.foo - &x.
This is unsafe for certain floats even in non-IEEE formats.
In IEEE, it is unsafe because it does wrong for NaNs.
Also note that operand_equal_p is always false if an operand
if (operand_equal_p (arg0
, arg1
, FLOAT_TYPE_P (type
)))
return convert (type
, integer_zero_node
);
if (! FLOAT_TYPE_P (type
))
if (integer_zerop (arg1
))
return omit_one_operand (type
, arg1
, arg0
);
return non_lvalue (convert (type
, arg0
));
/* (a * (1 << b)) is (a << b) */
if (TREE_CODE (arg1
) == LSHIFT_EXPR
&& integer_onep (TREE_OPERAND (arg1
, 0)))
return fold (build (LSHIFT_EXPR
, type
, arg0
,
TREE_OPERAND (arg1
, 1)));
if (TREE_CODE (arg0
) == LSHIFT_EXPR
&& integer_onep (TREE_OPERAND (arg0
, 0)))
return fold (build (LSHIFT_EXPR
, type
, arg1
,
TREE_OPERAND (arg0
, 1)));
/* x*0 is 0, except for IEEE floating point. */
if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
return omit_one_operand (type
, arg1
, arg0
);
/* In IEEE floating point, x*1 is not equivalent to x for snans.
However, ANSI says we can drop signals,
so we can do this anyway. */
return non_lvalue (convert (type
, arg0
));
if (! wins
&& real_twop (arg1
))
tree arg
= save_expr (arg0
); return build (PLUS_EXPR
, type
, arg
, arg
);
if (integer_all_onesp (arg1
))
return omit_one_operand (type
, arg1
, arg0
);
if (integer_zerop (arg1
))
return non_lvalue (convert (type
, arg0
));
t1
= distribute_bit_expr (code
, type
, arg0
, arg1
); /* (a << C1) | (a >> C2) if A is unsigned and C1+C2 is the size of A
is a rotate of A by C1 bits. */
if ((TREE_CODE (arg0
) == RSHIFT_EXPR
|| TREE_CODE (arg0
) == LSHIFT_EXPR
)
&& (TREE_CODE (arg1
) == RSHIFT_EXPR
|| TREE_CODE (arg1
) == LSHIFT_EXPR
)
&& TREE_CODE (arg0
) != TREE_CODE (arg1
)
&& operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
,0), 0)
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0)))
&& TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
&& TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
&& TREE_INT_CST_HIGH (TREE_OPERAND (arg1
, 1)) == 0
&& ((TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1))
+ TREE_INT_CST_LOW (TREE_OPERAND (arg1
, 1)))
== TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
TREE_CODE (arg0
) == LSHIFT_EXPR
? TREE_OPERAND (arg0
, 1) : TREE_OPERAND (arg1
, 1));
if (integer_zerop (arg1
))
return non_lvalue (convert (type
, arg0
));
if (integer_all_onesp (arg1
))
return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
if (integer_all_onesp (arg1
))
return non_lvalue (convert (type
, arg0
));
if (integer_zerop (arg1
))
return omit_one_operand (type
, arg1
, arg0
);
t1
= distribute_bit_expr (code
, type
, arg0
, arg1
); /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == NOP_EXPR
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1
, 0))))
int prec
= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1
, 0)));
if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
&& (~TREE_INT_CST_LOW (arg0
)
& (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg1
, 0));
if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
int prec
= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
&& (~TREE_INT_CST_LOW (arg1
)
& (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
if (integer_all_onesp (arg0
))
return non_lvalue (convert (type
, arg1
));
if (integer_zerop (arg0
))
return omit_one_operand (type
, arg0
, arg1
);
if (TREE_CODE (arg1
) == INTEGER_CST
)
arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
)); return non_lvalue (convert (type
, arg0
));
if (integer_zerop (arg1
))
/* If we have ((a * C1) / C2) and C1 % C2 == 0, we can replace this with
(a * (C1/C2). Also look for when we have a SAVE_EXPR in
if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_INT_CST_LOW (arg1
) > 0 && TREE_INT_CST_HIGH (arg1
) == 0
&& TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
&& TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)) > 0
&& TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
&& 0 == (TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1))
% TREE_INT_CST_LOW (arg1
)))
= build_int_2 (TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1))
/ TREE_INT_CST_LOW (arg1
), 0);
TREE_TYPE (new_op
) = type
;
return build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0), new_op
);
else if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_INT_CST_LOW (arg1
) > 0 && TREE_INT_CST_HIGH (arg1
) == 0
&& TREE_CODE (arg0
) == SAVE_EXPR
&& TREE_CODE (TREE_OPERAND (arg0
, 0)) == MULT_EXPR
&& (TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1))
&& (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1))
&& (TREE_INT_CST_HIGH (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1))
&& (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1))
% TREE_INT_CST_LOW (arg1
)) == 0)
= build_int_2 (TREE_INT_CST_LOW (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1))
/ TREE_INT_CST_LOW (arg1
), 0);
TREE_TYPE (new_op
) = type
;
return build (MULT_EXPR
, type
,
TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0), new_op
);
#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1
) == REAL_CST
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
return omit_one_operand (type
, integer_zero_node
, arg0
);
if (integer_zerop (arg1
))
if (integer_zerop (arg1
))
return non_lvalue (convert (type
, arg0
));
/* Since negative shift count is not well-defined,
don't try to compute it in the compiler. */
if (tree_int_cst_lt (arg1
, integer_zero_node
))
if (operand_equal_p (arg0
, arg1
, 0))
if (INTEGRAL_TYPE_P (type
)
&& operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
return omit_one_operand (type
, arg1
, arg0
);
if (operand_equal_p (arg0
, arg1
, 0))
if (INTEGRAL_TYPE_P (type
)
&& operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
return omit_one_operand (type
, arg1
, arg0
);
/* Note that the operand of this must be an int
and its values must be 0 or 1.
("true" is a fixed value perhaps depending on the language,
but we don't handle values other than 1 correctly yet.) */
return invert_truthvalue (arg0
);
/* Note that the operands of this must be ints
and their values must be 0 or 1.
("true" is a fixed value perhaps depending on the language.) */
/* If first arg is constant zero, return it. */
if (integer_zerop (arg0
))
/* If either arg is constant true, drop it. */
if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
return non_lvalue (arg1
);
if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
return non_lvalue (arg0
);
/* If second arg is constant zero, result is zero, but first arg
if (integer_zerop (arg1
))
return omit_one_operand (type
, arg1
, arg0
);
/* Check for the possibility of merging component references. If our
lhs is another similar operation, try to merge its rhs with our
rhs. Then try to merge our lhs and rhs. */
if (TREE_CODE (arg0
) == code
)
tem
= fold_truthop (code
, type
, TREE_OPERAND (arg0
, 1), arg1
);
return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
tem
= fold_truthop (code
, type
, arg0
, arg1
); /* Note that the operands of this must be ints
and their values must be 0 or true.
("true" is a fixed value perhaps depending on the language.) */
/* If first arg is constant true, return it. */
if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
/* If either arg is constant zero, drop it. */
if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
return non_lvalue (arg1
);
if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
))
return non_lvalue (arg0
);
/* If second arg is constant true, result is true, but we must
if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
return omit_one_operand (type
, arg1
, arg0
);
/* If either arg is constant zero, drop it. */
if (integer_zerop (arg0
))
return non_lvalue (arg1
);
if (integer_zerop (arg1
))
return non_lvalue (arg0
);
/* If either arg is constant true, this is a logical inversion. */
return non_lvalue (invert_truthvalue (arg1
));
return non_lvalue (invert_truthvalue (arg0
));
/* If one arg is a constant integer, put it last. */
if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) != INTEGER_CST
)
TREE_OPERAND (t
, 0) = arg1
;
TREE_OPERAND (t
, 1) = arg0
;
arg0
= TREE_OPERAND (t
, 0); arg1
= TREE_OPERAND (t
, 1); code
= swap_tree_comparison (code
); /* Convert foo++ == CONST into ++foo == CONST + INCR.
First, see if one arg is constant; find the constant arg
if (TREE_CONSTANT (arg1
))
constoploc
= &TREE_OPERAND (t
, 1), constop
= arg1
, varop
= arg0
; if (TREE_CONSTANT (arg0
))
constoploc
= &TREE_OPERAND (t
, 0), constop
= arg0
, varop
= arg1
; if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
/* This optimization is invalid for ordered comparisons
if CONST+INCR overflows or if foo+incr might overflow.
This optimization is invalid for floating point due to rounding.
For pointer types we assume overflow doesn't happen. */
if (TREE_CODE (TREE_TYPE (varop
)) == POINTER_TYPE
|| (! FLOAT_TYPE_P (TREE_TYPE (varop
))
&& (code
== EQ_EXPR
|| code
== NE_EXPR
)))
= fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
constop
, TREE_OPERAND (varop
, 1))); TREE_SET_CODE (varop
, PREINCREMENT_EXPR
);
else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
if (TREE_CODE (TREE_TYPE (varop
)) == POINTER_TYPE
|| (! FLOAT_TYPE_P (TREE_TYPE (varop
))
&& (code
== EQ_EXPR
|| code
== NE_EXPR
)))
= fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
constop
, TREE_OPERAND (varop
, 1))); TREE_SET_CODE (varop
, PREDECREMENT_EXPR
);
/* Change X >= CST to X > (CST - 1) if CST is positive. */
if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
&& ! tree_int_cst_lt (arg1
, integer_one_node
))
arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0); TREE_OPERAND (t
, 1) = arg1
;
arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0); TREE_OPERAND (t
, 1) = arg1
;
/* If this is an EQ or NE comparison with zero and ARG0 is
(1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
two operations, but the latter can be done in one less insn
one machine that have only two-operand insns or on which a
constant cannot be the first operand. */
if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
&& TREE_CODE (arg0
) == BIT_AND_EXPR
)
if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
&& integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
TREE_TYPE (TREE_OPERAND (arg0
, 0)),
TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
convert (TREE_TYPE (arg0
),
else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
&& integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
TREE_TYPE (TREE_OPERAND (arg0
, 1)),
TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
convert (TREE_TYPE (arg0
),
/* If this is an NE comparison of zero with an AND of one, remove the
comparison since the AND will give the correct value. */
if (code
== NE_EXPR
&& integer_zerop (arg1
)
&& TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (arg0
, 1)))
return convert (type
, arg0
);
/* If we have (A & C) == C where C is a power of 2, convert this into
(A & C) != 0. Similarly for NE_EXPR. */
if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
&& TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_pow2p (TREE_OPERAND (arg0
, 1))
&& operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
return build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
arg0
, integer_zero_node
); /* Simplify comparison of something with itself. (For IEEE
floating-point, we can only do some of these simplifications.) */
if (operand_equal_p (arg0
, arg1
, 0))
if (INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
/* For NE, we can only do this simplification if integer. */
if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
/* ... fall through ... */
/* An unsigned comparison against 0 can be simplified. */
&& (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
|| TREE_CODE (TREE_TYPE (arg1
)) == POINTER_TYPE
)
&& TREE_UNSIGNED (TREE_TYPE (arg1
)))
TREE_SET_CODE (t
, NE_EXPR
);
TREE_SET_CODE (t
, EQ_EXPR
);
return omit_one_operand (integer_type_node
,
return omit_one_operand (integer_type_node
,
integer_zero_node
, arg0
); /* If we are comparing an expression that just has comparisons
of two integer values, arithmetic expressions of those comparisons,
and constants, we can simplify it. There are only three cases
to check: the two values can either be equal, the first can be
greater, or the second can be greater. Fold the expression for
those three values. Since each value must be 0 or 1, we have
eight possibilities, each of which corresponds to the constant 0
or 1 or one of the six possible comparisons.
This handles common cases like (a > b) == 0 but also handles
expressions like ((x > y) - (y > x)) > 0, which supposedly
occur in macroized code. */
if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
tree cval1
= 0, cval2
= 0; if (twoval_comparison_p (arg0
, &cval1
, &cval2
)
/* Don't handle degenerate cases here; they should already
have been handled anyway. */
&& cval1
!= 0 && cval2
!= 0
&& ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
&& TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
&& INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
&& ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
)); tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
)); /* We can't just pass T to eval_subst in case cval1 or cval2
= fold (build (code
, type
,
eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
= fold (build (code
, type
,
eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
= fold (build (code
, type
,
eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
/* All three of these results should be 0 or 1. Confirm they
are. Then use those values to select the proper code
if ((integer_zerop (high_result
)
|| integer_onep (high_result
))
&& (integer_zerop (equal_result
)
|| integer_onep (equal_result
))
&& (integer_zerop (low_result
)
|| integer_onep (low_result
)))
/* Make a 3-bit mask with the high-order bit being the
value for `>', the next for '=', and the low for '<'. */
switch ((integer_onep (high_result
) * 4)
+ (integer_onep (equal_result
) * 2)
+ integer_onep (low_result
))
return omit_one_operand (type
, integer_zero_node
, arg0
);
return omit_one_operand (type
, integer_one_node
, arg0
);
return fold (build (code
, type
, cval1
, cval2
));
/* If this is a comparison of a field, we may be able to simplify it. */
if ((TREE_CODE (arg0
) == COMPONENT_REF
|| TREE_CODE (arg0
) == BIT_FIELD_REF
)
&& (code
== EQ_EXPR
|| code
== NE_EXPR
)
/* Handle the constant case even without -O
to make sure the warnings are given. */
&& (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
); /* From here on, the only cases we handle are when the result is
To compute GT, swap the arguments and do LT.
To compute GE, do LT and invert the result.
To compute LE, swap the arguments, do LT and invert the result.
To compute NE, do EQ and invert the result.
Therefore, the code below must handle only EQ and LT. */
if (code
== LE_EXPR
|| code
== GT_EXPR
)
tem
= arg0
, arg0
= arg1
, arg1
= tem
; code
= swap_tree_comparison (code
); /* Note that it is safe to invert for real values here because we
will check below in the one case that it matters. */
if (code
== NE_EXPR
|| code
== GE_EXPR
)
code
= invert_tree_comparison (code
); /* Compute a result for LT or EQ if args permit;
if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
t1
= build_int_2 ((TREE_INT_CST_LOW (arg0
) == TREE_INT_CST_LOW (arg1
))
&& (TREE_INT_CST_HIGH (arg0
)
== TREE_INT_CST_HIGH (arg1
)),
t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
)) ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
: INT_CST_LT (arg0
, arg1
)),
/* Assume a nonexplicit constant cannot equal an explicit one,
since such code would be undefined anyway.
Exception: on sysvr4, using #pragma weak,
a label can come out as 0. */
else if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == ADDR_EXPR
/* Two real constants can be compared explicitly. */
else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
/* If either operand is a NaN, the result is false with two
exceptions: First, an NE_EXPR is true on NaNs, but that case
is already handled correctly since we will be inverting the
result for NE_EXPR. Second, if we had inverted a LE_EXPR
or a GE_EXPR into a LT_EXPR, we must return true so that it
will be inverted into false. */
if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
|| REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0); else if (code
== EQ_EXPR
)
t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
), t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
), TREE_INT_CST_LOW (t1
) ^= 1;
if (TREE_CODE (arg0
) == INTEGER_CST
)
return TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1));
else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
return omit_one_operand (type
, arg1
, arg0
);
/* If the second operand is zero, invert the comparison and swap
the second and third operands. Likewise if the second operand
is constant and the third is not or if the third operand is
equivalent to the first operand of the comparison. */
|| (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
|| (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
&& operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
TREE_OPERAND (arg0
, 1))))
/* See if this can be inverted. If it can't, possibly because
it was a floating-point inequality comparison, don't do
tem
= invert_truthvalue (arg0
); if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
arg0
= TREE_OPERAND (t
, 0) = tem
; TREE_OPERAND (t
, 1) = TREE_OPERAND (t
, 2);
TREE_OPERAND (t
, 2) = arg1
;
arg1
= TREE_OPERAND (t
, 1); /* If we have A op B ? A : C, we may be able to convert this to a
simpler expression, depending on the operation and the values
of B and C. IEEE floating point prevents this though,
because A or B might be -0.0 or a NaN. */
if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
&& (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
|| ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
&& operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
arg1
, TREE_OPERAND (arg0
, 1))) tree arg2
= TREE_OPERAND (t
, 2); enum tree_code comp_code
= TREE_CODE (arg0
);
/* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
depending on the comparison operation. */
if (integer_zerop (TREE_OPERAND (arg0
, 1))
&& TREE_CODE (arg2
) == NEGATE_EXPR
&& operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
return fold (build1 (NEGATE_EXPR
, type
, arg1
));
return convert (type
, arg1
);
return fold (build1 (ABS_EXPR
, type
, arg1
));
return fold (build1 (NEGATE_EXPR
, type
,
fold (build1 (ABS_EXPR
, type
, arg1
))));
/* If this is A != 0 ? A : 0, this is simply A. For ==, it is
if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
if (comp_code
== NE_EXPR
)
return convert (type
, arg1
);
else if (comp_code
== EQ_EXPR
)
return convert (type
, integer_zero_node
);
/* If this is A op B ? A : B, this is either A, B, min (A, B),
or max (A, B), depending on the operation. */
if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
arg2
, TREE_OPERAND (arg0
, 0))) return convert (type
, arg2
);
return convert (type
, arg1
);
return fold (build (MIN_EXPR
, type
, arg1
, arg2
));
return fold (build (MAX_EXPR
, type
, arg1
, arg2
));
/* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
we might still be able to simplify this. For example,
if C1 is one less or one more than C2, this might have started
out as a MIN or MAX and been transformed by this function.
Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
if (INTEGRAL_TYPE_P (type
)
&& TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
&& TREE_CODE (arg2
) == INTEGER_CST
)
/* We can replace A with C1 in this case. */
arg1
= TREE_OPERAND (t
, 1) = convert (type
, TREE_OPERAND (arg0
, 1));
/* If C1 is C2 + 1, this is min(A, C2). */
if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
const_binop (PLUS_EXPR
, arg2
,
integer_one_node
, 0), 1)) return fold (build (MIN_EXPR
, type
, arg1
, arg2
));
/* If C1 is C2 - 1, this is min(A, C2). */
if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
const_binop (MINUS_EXPR
, arg2
,
integer_one_node
, 0), 1)) return fold (build (MIN_EXPR
, type
, arg1
, arg2
));
/* If C1 is C2 - 1, this is max(A, C2). */
if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
const_binop (MINUS_EXPR
, arg2
,
integer_one_node
, 0), 1)) return fold (build (MAX_EXPR
, type
, arg1
, arg2
));
/* If C1 is C2 + 1, this is max(A, C2). */
if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
&& operand_equal_p (TREE_OPERAND (arg0
, 1),
const_binop (PLUS_EXPR
, arg2
,
integer_one_node
, 0), 1)) return fold (build (MAX_EXPR
, type
, arg1
, arg2
));
/* Convert A ? 1 : 0 to simply A. */
if (integer_onep (TREE_OPERAND (t
, 1))
&& integer_zerop (TREE_OPERAND (t
, 2))
/* If we try to convert TREE_OPERAND (t, 0) to our type, the
call to fold will try to move the conversion inside
a COND, which will recurse. In that case, the COND_EXPR
is probably the best choice, so leave it alone. */
&& type
== TREE_TYPE (arg0
))
/* Look for expressions of the form A & 2 ? 2 : 0. The result of this
operation is simply A & 2. */
if (integer_zerop (TREE_OPERAND (t
, 2))
&& TREE_CODE (arg0
) == NE_EXPR
&& integer_zerop (TREE_OPERAND (arg0
, 1))
&& TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
&& operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
return convert (type
, TREE_OPERAND (arg0
, 0));
/* When pedantic, a compound expression can be neither an lvalue
nor an integer constant expression. */
if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
/* Don't let (0, 0) be null pointer constant. */
if (integer_zerop (arg1
))
return non_lvalue (arg1
);
return build_complex (arg0
, arg1
);
if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
else if (TREE_CODE (arg0
) == COMPLEX_CST
)
return TREE_REALPART (arg0
);
else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
return fold (build (TREE_CODE (arg0
), type
,
fold (build1 (REALPART_EXPR
, type
,
TREE_OPERAND (arg0
, 0))),
fold (build1 (REALPART_EXPR
,
type
, TREE_OPERAND (arg0
, 1))))); if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
return convert (type
, integer_zero_node
);
else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
else if (TREE_CODE (arg0
) == COMPLEX_CST
)
return TREE_IMAGPART (arg0
);
else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
return fold (build (TREE_CODE (arg0
), type
,
fold (build1 (IMAGPART_EXPR
, type
,
TREE_OPERAND (arg0
, 0))),
fold (build1 (IMAGPART_EXPR
, type
,
TREE_OPERAND (arg0
, 1)))));
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