tcg/optimize: Build and use o_bits in fold_andc

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2024-12-22 16:08:42 -08:00
parent 1e2edf85cc
commit d4d441e3a1

View file

@ -1452,7 +1452,7 @@ static bool fold_and(OptContext *ctx, TCGOp *op)
static bool fold_andc(OptContext *ctx, TCGOp *op)
{
uint64_t z_mask, s_mask;
uint64_t z_mask, o_mask, s_mask, a_mask;
TempOptInfo *t1, *t2;
if (fold_const2(ctx, op) ||
@ -1464,7 +1464,6 @@ static bool fold_andc(OptContext *ctx, TCGOp *op)
t1 = arg_info(op->args[1]);
t2 = arg_info(op->args[2]);
z_mask = t1->z_mask;
if (ti_is_const(t2)) {
/* Fold andc r,x,i to and r,x,~i. */
@ -1485,20 +1484,14 @@ static bool fold_andc(OptContext *ctx, TCGOp *op)
return fold_and(ctx, op);
}
/*
* Known-zeros does not imply known-ones. Therefore unless
* arg2 is constant, we can't infer anything from it.
*/
if (ti_is_const(t2)) {
uint64_t v2 = ti_const_val(t2);
if (fold_affected_mask(ctx, op, z_mask & v2)) {
return true;
}
z_mask &= ~v2;
}
z_mask = t1->z_mask & ~t2->o_mask;
o_mask = t1->o_mask & ~t2->z_mask;
s_mask = t1->s_mask & t2->s_mask;
return fold_masks_zs(ctx, op, z_mask, s_mask);
/* Affected bits are those not known zero, masked by those known zero. */
a_mask = t1->z_mask & t2->z_mask;
return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, a_mask);
}
static bool fold_bitsel_vec(OptContext *ctx, TCGOp *op)