Changed BRZ behavior to chomp a test word from stack instead of checking PSW_Z bit.

This eliminates the need for a preceding TEST syllable. The calculator has been updated.

diff --git a/docs/architecture_manual.md b/docs/architecture_manual.md
index 262c179..e2a7de3 100644 (file)
--- a/docs/architecture_manual.md
+++ b/docs/architecture_manual.md
@@ -14,7 +14,7 @@ Overview
 * Explicitly no MMU, just a flat, shared memory space. Think threads, not
   processes.
 
-Version: 1
+Version: 2
 
 Instruction Word Formats
 ------------------------
@@ -64,7 +64,7 @@ Syllables are defined as follows.
 | 000100 | SHIFT  | Pop TOS & NOS. Shift NOS by TOS bits to the left/right.    |
 | 000101 | CMPSWP | Compare-and-swap with ptr, old_val & new_val on stack.     |
 | 000110 | TEST   | Pop TOS and set PSW according to value.                    |
-| 000111 | BRZ    | Pop TOS. If PSW_Z==1, then set PC to popped value.         |
+| 000111 | BRZ    | Pop TOS & NOS. If NOS==0, then set PC to TOS value.        |
 | 000010 | LOAD   | Pop address from TOS, dereference and store to TOS.        |
 | 000011 | STORE  | Pop address from TOS, pop data from NOS, deref and store.  |
 | 000001 | NOP    | Do nothing.                                                |

diff --git a/docs/compat_matrix.md b/docs/compat_matrix.md
index eb6cb94..5faf44f 100644 (file)
--- a/docs/compat_matrix.md
+++ b/docs/compat_matrix.md
@@ -12,3 +12,4 @@ Compatibility Matrix
 |      1 |      1 |      1 |          1 |          1 |
 |      2 |      2 |      2 |          . |          . |
 |      3 |      . |      . |          . |          . |
+|      4 |      . |      . |          2 |          2 |

diff --git a/docs/instruction_reference.md b/docs/instruction_reference.md
index d8bc473..690623d 100644 (file)
--- a/docs/instruction_reference.md
+++ b/docs/instruction_reference.md
@@ -4,7 +4,7 @@ NED - Instruction Reference
 Overview
 --------
 
-Version: 1
+Version: 2
 
 Format A - Word
 ---------------
@@ -211,10 +211,9 @@ Description: Pops TOS and sets PSW flags accordingly.
     |      BRZ | 0 | 0 | 0 | 1 | 1 | 1 |
     +----------+---+---+---+---+---+---+
 
-Operation: PC = TOS if PSW_Z = 0
+Operation: PC = TOS if NOS = 0
 Indicators: None
-Description: Pops TOS. If PSW_Z = 0, loads value in to PC, pushing old PC on to
-             TOS.
+Description: Pops TOS and NOS. If NOS = 0, loads TOS value in to PC.
 
 --------------------------------------------------------------------------------
 

diff --git a/nedsim/nedsim.c b/nedsim/nedsim.c
index aa9b7c4..b88328b 100644 (file)
--- a/nedsim/nedsim.c
+++ b/nedsim/nedsim.c
@@ -18,7 +18,7 @@
 
 #include "../common/a.out.h"
 
-#define VERSION 3
+#define VERSION 4
 
 /* Bytes per word. */
 #define BPW 4
@@ -437,7 +437,8 @@ void
 ned_instruction_brz(struct NEDstate * state)
 {
     uint32_t new_pc = stack_pop(state->active_thread);
-    if (state->active_thread->psw->zero == true) {
+    uint32_t test_word = stack_pop(state->active_thread);
+    if (test_word == 0) {
         state->active_thread->pc = new_pc;
         /* TODO: Find better way to communicate we're skipping ahead to the next word. */
         state->active_thread->sc = 4;

diff --git a/software/4func_calculator/calc.asm b/software/4func_calculator/calc.asm
index 4386392..c3aeac5 100644 (file)
--- a/software/4func_calculator/calc.asm
+++ b/software/4func_calculator/calc.asm
@@ -88,7 +88,6 @@ calcinit
 
         # Check for loop termination
         LDSP+0
-        TEST
         BRZ>calcinitzeroloopend
             JMP>calcinitzeroloop
 
@@ -124,7 +123,6 @@ incrementstackindex
     LOAD
     IM_2        # Negative bit in PSW
     AND
-    TEST
     BRZ>incrementstackindexreturn
         # Negative bit was set, so wrap to start of stack.
         TEST
@@ -158,7 +156,6 @@ decrementstackindex
     LOAD
     IM_2    # Negative bit in PSW register.
     AND
-    TEST
     BRZ>decrementstackindexreturn
         # Negative bit was set, so wrap to end of stack.
         TEST
@@ -240,7 +237,6 @@ printbinaryinteger
 
     # First check if the number is zero and print a single zero if true.
     LDSP+0
-    TEST
     BRZ>printbinaryintegerloopend
 
     # Repeatedly divide by ten and push each digit onto the stack in ASCII.
@@ -248,7 +244,6 @@ printbinaryinteger
 
     # Verify Integer still has digits to print (i.e. Integer != 0)
     LDSP+0
-    TEST
     BRZ>printbinaryintegerloopend
 
         # Extract the least significant digit.
@@ -282,7 +277,6 @@ printbinaryinteger
     #   Sign flag (nonzero for negative result, 0 for positive result)
 
     # Push sign onto stack as ASCII character.
-    TEST
     BRZ>printbinaryintegerpositive
 
         # Add ASCII '-' sign to stack
@@ -356,7 +350,6 @@ evalzerostackentry
     IM_1
     ADD
     JSR>subtract
-    TEST
     BRZ>evalzerostackentrymatch
 
         # No match, return from subroutine
@@ -401,7 +394,6 @@ evalstacknavigation
     # Test for ASCII ','
     WORD_44 # ASCII ','
     JSR>subtract
-    TEST
     BRZ>evalstacknavigationprevmatch
 
         # No match.
@@ -431,7 +423,6 @@ evalstacknavigation
     # Test for ASCII '.'
     WORD_46 # ASCII '.'
     JSR>subtract
-    TEST
     BRZ>evalstacknavigationnextmatch
 
         # No match.
@@ -470,7 +461,6 @@ evalnegatestackentry
     IM_1
     ADD
     JSR>subtract
-    TEST
     BRZ>evalnegatestackentrymatch
 
         # No match, return from subroutine
@@ -519,7 +509,6 @@ evalmathaddition
     IM_13
     ADD
     JSR>subtract
-    TEST
     BRZ>evalmathadditionmatch
 
         # No match, return from subroutine
@@ -587,7 +576,6 @@ evalmathsubtraction
     IM_15
     ADD
     JSR>subtract
-    TEST
     BRZ>evalmathsubtractionmatch
 
         # No match, return from subroutine
@@ -655,7 +643,6 @@ evalmathmultiplication
     IM_12
     ADD
     JSR>subtract
-    TEST
     BRZ>evalmathmultiplicationmatch
 
         # No match, return from subroutine
@@ -724,7 +711,6 @@ evalmathdivision
     IM_17
     ADD
     JSR>subtract
-    TEST
     BRZ>evalmathdivisionmatch
 
         # No match, return from subroutine
@@ -801,7 +787,6 @@ evalasciidigit
 
     # Test for ASCII digit.
     JSR>isasciidigit
-    TEST
     BRZ>evalasciidigitmatch
 
         # No match, return from subroutine
@@ -859,7 +844,6 @@ isasciidigit
     LOAD
     IM_2
     AND
-    TEST
     BRZ>isasciidigitcontinued
         # The result was negative, so clean up stack and return false.
         IM_1
@@ -876,7 +860,6 @@ isasciidigit
     LOAD
     IM_2
     AND
-    TEST
     BRZ>isasciidigitfalse
         # The result was true, so clean up stack and return true.
         IM_0
@@ -957,7 +940,6 @@ absolutevalue
     IM_4
     LOAD
     AND
-    TEST
     BRZ>absolutevaluereturn
         JSR>negate
 
@@ -1024,7 +1006,6 @@ multiply
         SHIFT
         IM_1
         AND
-        TEST
         BRZ>skipadd
             # If indicated by a 1 bit, shift and add first operand to result.
             LDSP+3          # X Operand
@@ -1046,7 +1027,6 @@ multiply
     LDSP+1                  # Shift magnitude
     IM_30
     JSR>subtract
-    TEST
     BRZ>multiplycleanup
         JMP>testbit
 
@@ -1064,7 +1044,6 @@ multiply
     # Set the sign of the product.
     applysign
         SWAP
-        TEST
         BRZ>multiplyreturn
             JSR>negate
 
@@ -1100,7 +1079,6 @@ divide
 
     # Check for zero divisor
     LDSP+0
-    TEST
     BRZ>divideexception
 
     # Generate a sign flag and store it behind the operands.
@@ -1139,7 +1117,6 @@ divide
         LDSP+2 # Cycle Counter
         IM_1
         ADD
-        TEST
         BRZ>divisionloopend
 
             # While Cycle Counter >= 0
@@ -1170,7 +1147,6 @@ divide
             AND
             IM_2
             XOR
-            TEST
             BRZ>divisionsubloopend
 
                 # If Remainder >= Divisor
@@ -1217,7 +1193,6 @@ divide
 
     # Set sign of results.
     LDSP+2 # Sign flag
-    TEST
     BRZ>divisioncleanup
         JSR>negate
         SWAP
@@ -1308,7 +1283,6 @@ itoa
     LOAD
     IM_2
     AND
-    TEST
     BRZ>itoahalt
     # Verify that operand > -1
     LDSP+0
@@ -1320,7 +1294,6 @@ itoa
     AND
     IM_2
     XOR
-    TEST
     BRZ>itoahalt # Branch if operand was negative.
     # Convert the integer to its ASCII representation and return to caller.
     WORD_48
@@ -1349,7 +1322,6 @@ putchar
     putcharloop
         LDSP+0
         LOAD
-        TEST
         BRZ>putcharloop
     TEST # Drop XCSR from stack
     SWAP
@@ -1373,7 +1345,6 @@ getchar
     getcharloop
         LDSP+0
         LOAD
-        TEST
         BRZ>getcharloop
     LDSP+1
     LOAD
@@ -1396,6 +1367,7 @@ printstring
 #   Return PC <-- TOS
 ##########################################################################################
     SWAP
+    LDSP+0
     BRZ>printstringreturn
     JSR>putchar
     JMP>printstring