From: WANG Rui <wangrui@loongson.cn>
Date: Fri, 19 Sep 2025 12:49:01 +0000 (+0800)
Subject: tcg/optimize: Fix folding of vector bitsel
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a50347a4145faf6d409afd4b9b682c8b3e60854a;p=thirdparty%2Fqemu.git

tcg/optimize: Fix folding of vector bitsel

It looks like a typo. When the false value (C) is the constant -1, the
correct fold should be: R = B | ~A

Reproducer (LoongArch64 assembly):

     .text
     .globl  _start
 _start:
     vldi    $vr1, 3073
     vldi    $vr2, 1023
     vbitsel.v       $vr0, $vr2, $vr1, $vr2
     vpickve2gr.d    $a1, $vr0, 1
     xori    $a0, $a1, 1
     li.w    $a7, 93
     syscall 0

Fixes: e58b977238e3 ("tcg/optimize: Optimize bitsel_vec")
Link: https://github.com/llvm/llvm-project/issues/159610
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250919124901.2756538-1-wangrui@loongson.cn>
---

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 3638ab9fea0..f69702b26e8 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1568,9 +1568,10 @@ static bool fold_bitsel_vec(OptContext *ctx, TCGOp *op)
             return fold_and(ctx, op);
         }
         if (fv == -1 && TCG_TARGET_HAS_orc_vec) {
+            TCGArg ta = op->args[2];
             op->opc = INDEX_op_orc_vec;
             op->args[2] = op->args[1];
-            op->args[1] = op->args[3];
+            op->args[1] = ta;
             return fold_orc(ctx, op);
         }
     }