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simul assignment

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SVN=124591
This commit is contained in:
Ken Thompson 2008-06-25 11:35:06 -07:00
parent deaac9800f
commit 1a3f944530
1 changed files with 86 additions and 11 deletions
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97
src/cmd/gc/walk.c
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@ -1908,42 +1908,117 @@ loop1:
/*
* from ascompat[ee]
* a,b = c,d
* simultaneous assignment. there can be
* later use of an earlier lvalue.
* simultaneous assignment. there cannot
* be later use of an earlier lvalue.
*/
int
vmatch(Node *l, Node *r)
vmatch2(Node *l, Node *r)
{
dump("l", l);
dump("r", r);
return 0;
loop:
/*
* isolate all right sides
*/
if(r == N)
return 0;
switch(r->op) {
case ONAME:
// match each right given left
if(l == r)
return 1;
case OLITERAL:
return 0;
}
if(vmatch2(l, r->right))
return 1;
r = r->left;
goto loop;
}
int
vmatch1(Node *l, Node *r)
{
loop:
/*
* isolate all left sides
*/
if(l == N)
return 0;
switch(l->op) {
case ONAME:
// match each left with all rights
return vmatch2(l, r);
case OLITERAL:
return 0;
}
if(vmatch1(l->right, r))
return 1;
l = l->left;
goto loop;
}
Node*
reorder3(Node *n)
{
Iter save1, save2;
Node *l1, *l2;
Node *l1, *l2, *q, *r;
int c1, c2;
r = N;
l1 = listfirst(&save1, &n);
c1 = 0;
while(l1 != N) {
l2 = listfirst(&save1, &n);
l2 = listfirst(&save2, &n);
c2 = 0;
while(l2 != N) {
if(c2 > c1) {
if(vmatch(l1->left, l2->right)) {
if(vmatch1(l1->left, l2->right)) {
q = nod(OXXX, N, N);
tempname(q, l2->right->type);
q = nod(OAS, l1->left, q);
l1->left = q->right;
if(r == N)
r = q;
else
r = nod(OLIST, r, q);
break;
}
}
l2 = listnext(&save1);
l2 = listnext(&save2);
c2++;
}
l1 = listnext(&save1);
c1++;
}
return n;
if(r == N)
return n;
q = N;
l1 = listfirst(&save1, &n);
while(l1 != N) {
if(q == N)
q = l1;
else
q = nod(OLIST, q, l1);
l1 = listnext(&save1);
}
r = rev(r);
l1 = listfirst(&save1, &r);
while(l1 != N) {
if(q == N)
q = l1;
else
q = nod(OLIST, q, l1);
l1 = listnext(&save1);
}
q = rev(q);
//dump("res", q);
return q;
}
Node*