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one more time for divide

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SVN=127911
This commit is contained in:
Ken Thompson 2008-07-17 16:22:40 -07:00
parent 85303f2715
commit 41861ca7bb
1 changed files with 42 additions and 44 deletions
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86
src/cmd/6g/gen.c
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@ -945,33 +945,28 @@ samereg(Node *a, Node *b)
}
void
dodiv(int op, Node *nl, Node *nr, Node *res)
dodiv(int op, Node *nl, Node *nr, Node *res, Node *ax, Node *dx)
{
int a;
Node n1, n2, n3;
nodreg(&n1, types[TINT64], D_AX);
nodreg(&n2, types[TINT64], D_DX);
regalloc(&n1, nl->type, &n1);
regalloc(&n2, nl->type, &n2);
Node n3;
a = optoas(op, nl->type);
if(!issigned[nl->type->etype]) {
nodconst(&n3, nl->type, 0);
gmove(&n3, &n2);
gmove(&n3, dx);
}
regalloc(&n3, nr->type, N);
if(nl->ullman >= nr->ullman) {
cgen(nl, &n1);
cgen(nl, ax);
if(issigned[nl->type->etype])
gins(optoas(OFOR, nl->type), N, N);
cgen(nr, &n3);
gins(a, &n3, N);
} else {
cgen(nr, &n3);
cgen(nl, &n1);
cgen(nl, ax);
if(issigned[nl->type->etype])
gins(optoas(OFOR, nl->type), N, N);
gins(a, &n3, N);
@ -979,12 +974,9 @@ dodiv(int op, Node *nl, Node *nr, Node *res)
regfree(&n3);
if(op == ODIV)
gmove(&n1, res);
gmove(ax, res);
else
gmove(&n2, res);
regfree(&n1);
regfree(&n2);
gmove(dx, res);
}
/*
@ -995,62 +987,68 @@ dodiv(int op, Node *nl, Node *nr, Node *res)
void
cgen_div(int op, Node *nl, Node *nr, Node *res)
{
Node n1, n2, n3, n4, n5;
Node ax, dx, n3, tmpax, tmpdx;
int a, rax, rdx;
rax = reg[D_AX];
rdx = reg[D_DX];
nodreg(&n1, types[TINT64], D_AX);
nodreg(&n2, types[TINT64], D_DX);
nodreg(&ax, types[TINT64], D_AX);
nodreg(&dx, types[TINT64], D_DX);
regalloc(&ax, nl->type, &ax);
regalloc(&dx, nl->type, &dx);
// clean out the AX register
if(rax && !samereg(res, &n1)) {
if(rdx && !samereg(res, &n2)) {
regalloc(&n5, types[TINT64], N); // DX holder
regalloc(&n4, types[TINT64], N); // AX holder
if(rax && !samereg(res, &ax)) {
if(rdx && !samereg(res, &dx)) {
regalloc(&tmpdx, types[TINT64], N);
regalloc(&tmpax, types[TINT64], N);
regalloc(&n3, nl->type, N); // dest for div
gins(AMOVQ, &n2, &n5);
gins(AMOVQ, &n1, &n4);
dodiv(op, nl, nr, &n3);
gins(AMOVQ, &n4, &n1);
gins(AMOVQ, &n5, &n2);
gins(AMOVQ, &dx, &tmpdx);
gins(AMOVQ, &ax, &tmpax);
dodiv(op, nl, nr, &n3, &ax, &dx);
gins(AMOVQ, &tmpax, &ax);
gins(AMOVQ, &tmpdx, &dx);
gmove(&n3, res);
regfree(&n5);
regfree(&n4);
regfree(&tmpdx);
regfree(&tmpax);
regfree(&n3);
return;
goto ret;
}
regalloc(&n4, types[TINT64], N); // AX holder
regalloc(&tmpax, types[TINT64], N);
regalloc(&n3, nl->type, N); // dest for div
gins(AMOVQ, &n1, &n4);
dodiv(op, nl, nr, &n3);
gins(AMOVQ, &n4, &n1);
gins(AMOVQ, &ax, &tmpax);
dodiv(op, nl, nr, &n3, &ax, &dx);
gins(AMOVQ, &tmpax, &ax);
gmove(&n3, res);
regfree(&n4);
regfree(&tmpax);
regfree(&n3);
return;
goto ret;
}
// clean out the DX register
if(rdx && !samereg(res, &n2)) {
regalloc(&n4, types[TINT64], N); // DX holder
if(rdx && !samereg(res, &dx)) {
regalloc(&tmpdx, types[TINT64], N);
regalloc(&n3, nl->type, N); // dest for div
gins(AMOVQ, &n2, &n4);
dodiv(op, nl, nr, &n3);
gins(AMOVQ, &n4, &n2);
gins(AMOVQ, &dx, &tmpdx);
dodiv(op, nl, nr, &n3, &ax, &dx);
gins(AMOVQ, &tmpdx, &dx);
gmove(&n3, res);
regfree(&n4);
regfree(&tmpdx);
regfree(&n3);
return;
goto ret;
}
dodiv(op, nl, nr, res);
dodiv(op, nl, nr, res, &ax, &dx);
ret:
regfree(&ax);
regfree(&dx);
}
/*