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6c: eleminate more MOV instructions

Browse source 
convert:

x = B || W
MOVxLZX a, r; MOVxQZX r, b -> MOVxQZX a, r; MOVQ r, b
MOVxLSX a, r; MOVxQSX r, r -> MOVxQSX a, r; MOVQ r, r

the MOVQ can then be eleminated by copy propagation.

improve subprop() by accepting other mov and lea
instructions as the source op.
This commit is contained in:
cinap_lenrek 2015-02-18 23:34:33 +01:00
parent 8210f857f1
commit 0037c93433
1 changed files with 27 additions and 5 deletions
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32
sys/src/cmd/6c/peep.c
View file

@ -121,7 +121,17 @@ loop1:
r1 = rnops(uniqs(r));
if(r1 != R) {
p1 = r1->prog;
if(p->as == p1->as && p->to.type == p1->from.type){
if(p->to.type != p1->from.type)
break;
if((p->as == AMOVBLZX && p1->as == AMOVBQZX)
|| (p->as == AMOVWLZX && p1->as == AMOVWQZX)
|| (p->as == AMOVBLSX && p1->as == AMOVBQSX && p1->to.type == p->to.type)
|| (p->as == AMOVWLSX && p1->as == AMOVWQSX && p1->to.type == p->to.type)) {
p->as = p1->as;
p1->as = AMOVQ;
t++;
} else
if(p->as == p1->as) {
p1->as = AMOVL;
t++;
}
@ -401,10 +411,6 @@ subprop(Reg *r0)
case ACWD:
case ACDQ:
case ACQO:
case AMOVSL:
case AMOVSQ:
case AMOVQL:
return 0;
case AORL:
@ -432,7 +438,23 @@ subprop(Reg *r0)
break;
case AMOVL:
case ALEAL:
case AMOVSL:
case AMOVBLZX:
case AMOVBLSX:
case AMOVWLZX:
case AMOVWLSX:
case AMOVQL:
case AMOVQ:
case ALEAQ:
case AMOVSQ:
case AMOVBQZX:
case AMOVBQSX:
case AMOVWQZX:
case AMOVWQSX:
case AMOVLQZX:
case AMOVLQSX:
if(p->to.type == v1->type)
goto gotit;
break;