vc4: Optimize out adds of 0.

This commit is contained in:
Eric Anholt 2014-10-09 15:10:52 +02:00
parent 0401f55fff
commit 7e67ea994c

View file

@ -98,6 +98,18 @@ replace_with_mov(struct vc4_compile *c, struct qinst *inst, struct qreg arg)
dump_to(c, inst);
}
static bool
add_replace_zero(struct vc4_compile *c,
struct qinst **defs,
struct qinst *inst,
int arg)
{
if (!is_zero(c, defs, inst->src[arg]))
return false;
replace_with_mov(c, inst, inst->src[1 - arg]);
return true;
}
static bool
fmul_replace_zero(struct vc4_compile *c,
struct qinst **defs,
@ -181,7 +193,21 @@ qir_opt_algebraic(struct vc4_compile *c)
}
break;
case QOP_ADD:
if (add_replace_zero(c, defs, inst, 0) ||
add_replace_zero(c, defs, inst, 1)) {
progress = true;
break;
}
break;
case QOP_FADD:
if (add_replace_zero(c, defs, inst, 0) ||
add_replace_zero(c, defs, inst, 1)) {
progress = true;
break;
}
/* FADD(a, FSUB(0, b)) -> FSUB(a, b) */
if (inst->src[1].file == QFILE_TEMP &&
defs[inst->src[1].index]->op == QOP_FSUB) {