Commit | Line | Data |
---|---|---|
42d6e430 BJ |
1 | #include <stdio.h> |
2 | #include "def.h" | |
3 | #include "3.def.h" | |
4 | ||
5 | #define ARCCOUNT(v) REACH(v) | |
6 | ||
7 | ||
8 | fixhd(v,hd,head) | |
9 | VERT v,hd,*head; | |
10 | { | |
11 | VERT w,newhd; | |
12 | int i; | |
13 | head[v] = hd; | |
14 | newhd = (NTYPE(v) == ITERVX) ? v : hd; | |
15 | for (i = 0; i < CHILDNUM(v); ++i) | |
16 | for (w = LCHILD(v,i); DEFINED(w); w = RSIB(w)) | |
17 | fixhd(w,newhd,head); | |
18 | } | |
19 | ||
20 | getloop() | |
21 | { | |
22 | cntarcs(); | |
23 | fixloop(START); | |
24 | } | |
25 | ||
26 | ||
27 | cntarcs() /* count arcs entering each node */ | |
28 | { | |
29 | VERT w,v; | |
30 | int i; | |
31 | for (v = 0; v < nodenum; ++v) | |
32 | ARCCOUNT(v) = 0; | |
33 | for (v = 0; v < nodenum; ++v) | |
34 | for (i = 0; i < ARCNUM(v); ++i) | |
35 | { | |
36 | w = ARC(v,i); | |
37 | if (!DEFINED(w)) continue; | |
38 | ++ARCCOUNT(w); | |
39 | } | |
40 | } | |
41 | ||
42 | ||
43 | fixloop(v) /* find WHILE loops */ | |
44 | VERT v; | |
45 | { | |
46 | int recvar; | |
47 | if (NTYPE(v) == LOOPVX) | |
48 | { | |
49 | ASSERT(DEFINED(ARC(v,0)),fixloop); | |
50 | NXT(ARC(v,0)) = ARC(v,0); | |
51 | if (!getwh(v)) | |
52 | getun(v); | |
53 | } | |
54 | else if (NTYPE(v) == IFVX && arbcase) | |
55 | getswitch(v); | |
56 | else if (NTYPE(v)==DOVX) | |
57 | { | |
58 | ASSERT(DEFINED(ARC(v,0)),fixloop); | |
59 | NXT(ARC(v,0))=ARC(v,0); | |
60 | } | |
61 | RECURSE(fixloop,v,recvar); | |
62 | } | |
63 | ||
64 | ||
65 | getwh(v) | |
66 | VERT v; | |
67 | { | |
68 | VERT vchild, vgrand,vgreat; | |
69 | ASSERT(NTYPE(v) == LOOPVX,getwh); | |
70 | vchild = LCHILD(v,0); | |
71 | ASSERT(DEFINED(vchild),getwh); | |
72 | ASSERT(NTYPE(vchild) == ITERVX,getwh); | |
73 | vgrand = LCHILD(vchild,0); | |
74 | if (!DEFINED(vgrand) || !IFTHEN(vgrand) ) | |
75 | return(FALSE); | |
76 | vgreat = LCHILD(vgrand,THEN); | |
77 | if (DEFINED(vgreat) && NTYPE(vgreat) == GOVX && ARC(vgreat,0) == BRK(vchild)) | |
78 | { | |
79 | /* turn into WHILE */ | |
80 | NTYPE(v) = WHIVX; | |
81 | NEG(vgrand) = !NEG(vgrand); | |
82 | LPRED(vchild) = vgrand; | |
83 | LCHILD(vchild,0) = RSIB(vgrand); | |
84 | RSIB(vgrand) = UNDEFINED; | |
85 | return(TRUE); | |
86 | } | |
87 | return(FALSE); | |
88 | } | |
89 | ||
90 | ||
91 | ||
92 | getun(v) /* change loop to REPEAT UNTIL if possible */ | |
93 | VERT v; | |
94 | { | |
95 | VERT vchild, vgrand, vgreat, before, ch; | |
96 | ASSERT(NTYPE(v) == LOOPVX,getun); | |
97 | vchild = LCHILD(v,0); | |
98 | ASSERT(DEFINED(vchild), getun); | |
99 | if (ARCCOUNT(vchild) > 2) | |
100 | return(FALSE); /* loop can be iterated without passing through predicate of UNTIL */ | |
101 | vgrand = ARC(vchild,0); | |
102 | if (!DEFINED(vgrand)) | |
103 | return(FALSE); | |
104 | for (ch = vgrand,before = UNDEFINED; DEFINED(RSIB(ch)); ch = RSIB(ch)) | |
105 | before = ch; | |
106 | if (!IFTHEN(ch)) | |
107 | return(FALSE); | |
108 | vgreat = LCHILD(ch,THEN); | |
109 | if (DEFINED(vgreat) && NTYPE(vgreat) == GOVX && ARC(vgreat,0) == BRK(vchild)) | |
110 | { | |
111 | /* create UNTIL node */ | |
112 | NTYPE(v) = UNTVX; | |
113 | NXT(vchild) = ch; | |
114 | LPRED(vchild)=ch; | |
115 | RSIB(before) = UNDEFINED; | |
116 | return(TRUE); | |
117 | } | |
118 | return(FALSE); | |
119 | } | |
120 | ||
121 | ||
122 | #define FORMCASE(w) (DEFINED(w) && !DEFINED(RSIB(w)) && NTYPE(w) == IFVX && ARCCOUNT(w) == 1) | |
123 | ||
124 | getswitch(v) | |
125 | VERT v; | |
126 | { | |
127 | VERT ch, grand, temp; | |
128 | /* must be of form if ... else if ... else if ... */ | |
129 | if (NTYPE(v) != IFVX) return(FALSE); | |
130 | ch = LCHILD(v,ELSE); | |
131 | if (!FORMCASE(ch)) return(FALSE); | |
132 | grand = LCHILD(ch,ELSE); | |
133 | if (!FORMCASE(grand)) return(FALSE); | |
134 | ||
135 | temp = create(SWCHVX,0); | |
136 | exchange(&graph[temp],&graph[v]); /* want arcs to enter switch, not first case*/ | |
137 | BEGCOM(v) = UNDEFINED; | |
138 | RSIB(v) = RSIB(temp); /* statements which followed IFVX should follow switch */ | |
139 | EXP(v) = UNDEFINED; | |
140 | LCHILD(v,0) = temp; | |
141 | NTYPE(temp) = ACASVX; | |
142 | for (ch = LCHILD(temp,ELSE); FORMCASE(ch); ) | |
143 | { | |
144 | LCHILD(temp,ELSE) = UNDEFINED; | |
145 | RSIB(temp) = ch; | |
146 | NTYPE(ch) = ACASVX; | |
147 | temp = ch; | |
148 | ch = LCHILD(temp,ELSE); | |
149 | } | |
150 | ASSERT(!DEFINED(RSIB(temp)),getswitch); | |
151 | return(TRUE); | |
152 | } |