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8 shift bug

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R=ken
OCL=32882
CL=32882
This commit is contained in:
Russ Cox 2009-08-07 12:57:44 -07:00
parent c30d81bd23
commit 76a763e0be
1 changed files with 29 additions and 2 deletions
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31
src/cmd/8g/ggen.c
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@ -499,6 +499,18 @@ ret:
;
}
int
samereg(Node *a, Node *b)
{
if(a->op != OREGISTER)
return 0;
if(b->op != OREGISTER)
return 0;
if(a->val.u.reg != b->val.u.reg)
return 0;
return 1;
}
/*
* generate division.
* caller must set:
@ -581,7 +593,7 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
void
cgen_shift(int op, Node *nl, Node *nr, Node *res)
{
Node n1, n2;
Node n1, n2, cx, oldcx;
int a, w;
Prog *p1;
uvlong sc;
@ -611,10 +623,20 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
return;
}
memset(&oldcx, 0, sizeof oldcx);
nodreg(&cx, types[TUINT32], D_CX);
if(reg[D_CX] > 0 && !samereg(&cx, res)) {
regalloc(&oldcx, types[TUINT32], N);
gmove(&cx, &oldcx);
}
nodreg(&n1, types[TUINT32], D_CX);
regalloc(&n1, nr->type, &n1); // to hold the shift type in CX
regalloc(&n2, nl->type, res);
if(samereg(&cx, res))
regalloc(&n2, nl->type, N);
else
regalloc(&n2, nl->type, res);
if(nl->ullman >= nr->ullman) {
cgen(nl, &n2);
cgen(nr, &n1);
@ -633,6 +655,11 @@ cgen_shift(int op, Node *nl, Node *nr, Node *res)
}
patch(p1, pc);
gins(a, &n1, &n2);
if(oldcx.op != 0) {
gmove(&oldcx, &cx);
regfree(&oldcx);
}
gmove(&n2, res);