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6c: MOVL xxx, r; MOVLQZX r, r -> MOVL xxx, r

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eleminate MOVLQXZ instructions after MOVL as MOVL implicitely
zero extends the result.
This commit is contained in:
cinap_lenrek 2015-03-17 16:12:01 +01:00
parent 972cd5e3fc
commit f5f9ecdcfa
1 changed files with 15 additions and 2 deletions
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17
sys/src/cmd/6c/peep.c
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@ -100,15 +100,28 @@ loop1:
case AMOVQ:
case AMOVSS:
case AMOVSD:
if(regtyp(&p->to))
if(!regtyp(&p->to))
break;
if(regtyp(&p->from)) {
if(copyprop(r)) {
excise(r);
t++;
} else
break;
}
if(subprop(r) && copyprop(r)) {
excise(r);
t++;
break;
}
}
if(p->as != AMOVL)
break;
r1 = rnops(uniqs(r));
if(r1 != R){
p1 = r1->prog;
if(p1->as == AMOVLQZX && p1->from.type == p->to.type && p1->to.type == p->to.type){
excise(r1);
t++;
}
}
break;