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sys/src/cmd/cc: fix special case for null pointer constants in cond expressions #36

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sys/src/cmd/cc: fix special case for null pointer constants in cond expressions #36

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1 change: 1 addition & 0 deletions sys/src/cmd/cc/cc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -694,6 +694,7 @@ Type* copytyp(Type*);
void typeext(Type*, Node*);
void typeext1(Type*, Node*);
int side(Node*);
int zpconst(Node*);
int vconst(Node*);
int log2(uvlong);
int vlog(Node*);
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6 changes: 4 additions & 2 deletions sys/src/cmd/cc/com.c
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Original file line number Diff line number Diff line change
Expand Up @@ -331,11 +331,13 @@ tcomo(Node *n, int f)
o |= tcom(r->left);
if(o | tcom(r->right))
goto bad;
if(r->right->type->etype == TIND && vconst(r->left) == 0) {
if(r->right->type->etype == TIND && zpconst(r->left)) {
r->type = r->right->type;
r->left->type = r->right->type;
r->left->vconst = 0;
}
if(r->left->type->etype == TIND && vconst(r->right) == 0) {
if(r->left->type->etype == TIND && zpconst(r->right)) {
r->type = r->left->type;
r->right->type = r->left->type;
r->right->vconst = 0;
}
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15 changes: 15 additions & 0 deletions sys/src/cmd/cc/sub.c
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Expand Up @@ -987,6 +987,21 @@ side(Node *n)
return 1;
}

int
zpconst(Node *n)
{
while(n->op == OCAST){
if(n->type == T)
break;
if(n->type->etype != TIND)
break;
if(n->type->link->etype != TVOID)
break;
n = n->left;
}
return vconst(n) == 0;
}

int
vconst(Node *n)
{
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