tcg/optimize: Do use affected bits

We inadvertently disabled affected bits optimizations on operations
that use fold_masks_zosa.  These happen relatively often in x86 code
for extract/sextract; for example given the following:

   mov %esi, %ebp
   xor $0x1, %ebp

the optimizer is able to simplify the "extract_i64 rbp,tmp0,$0x0,$0x20"
produced by the second instruction to a move.

Cc: qemu-stable@nongnu.org
Fixes: 932522a9ddc ("tcg/optimize: Fold and to extract during optimize")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20251223163720.985578-1-pbonzini@redhat.com>

diff --git a/tcg/optimize.c b/tcg/optimize.c
index db1d89396b079ad006140ec2bf5deee7db4c93cf..5ae26e4a100f540efd1ff2a5a362c4b1f735d410 100644 (file)
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1103,7 +1103,7 @@ static bool fold_masks_zosa_int(OptContext *ctx, TCGOp *op,
 static bool fold_masks_zosa(OptContext *ctx, TCGOp *op, uint64_t z_mask,
                             uint64_t o_mask, int64_t s_mask, uint64_t a_mask)
 {
-    fold_masks_zosa_int(ctx, op, z_mask, o_mask, s_mask, -1);
+    fold_masks_zosa_int(ctx, op, z_mask, o_mask, s_mask, a_mask);
     return true;
 }