diff options
Diffstat (limited to 'src/cmd/gc/cplx.c')
| -rw-r--r-- | src/cmd/gc/cplx.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/src/cmd/gc/cplx.c b/src/cmd/gc/cplx.c index 3ec9fe5a2..890cf7f10 100644 --- a/src/cmd/gc/cplx.c +++ b/src/cmd/gc/cplx.c @@ -12,6 +12,19 @@ static void minus(Node *nl, Node *res); #define CASE(a,b) (((a)<<16)|((b)<<0)) +static int +overlap(Node *f, Node *t) +{ + // check whether f and t could be overlapping stack references. + // not exact, because it's hard to check for the stack register + // in portable code. close enough: worst case we will allocate + // an extra temporary and the registerizer will clean it up. + return f->op == OINDREG && + t->op == OINDREG && + f->xoffset+f->type->width >= t->xoffset && + t->xoffset+t->type->width >= f->xoffset; +} + /* * generate: * res = n; @@ -43,9 +56,10 @@ complexmove(Node *f, Node *t) case CASE(TCOMPLEX64,TCOMPLEX128): case CASE(TCOMPLEX128,TCOMPLEX64): case CASE(TCOMPLEX128,TCOMPLEX128): - // complex to complex move/convert - // make from addable - if(!f->addable) { + // complex to complex move/convert. + // make f addable. + // also use temporary if possible stack overlap. + if(!f->addable || overlap(f, t)) { tempname(&n1, f->type); complexmove(f, &n1); f = &n1; |