Commit 23b53ec3a8 for qemu.org

commit 23b53ec3a8a279cb5acd5e022b464a4272fe9f8c
Author: Paolo Bonzini <pbonzini@redhat.com>
Date:   Tue Dec 23 17:37:20 2025 +0100

    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 db1d89396b..5ae26e4a10 100644
--- 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;
 }