From 121531751087ad3f8d87ad17068835bbcd14fb02 Mon Sep 17 00:00:00 2001
From: Qi Hu
Date: Mon, 24 Oct 2022 10:41:55 +0200
Subject: target/i386: Fix calculation of LOCK NEG eflags

After:

        lock negl -0x14(%rbp)
        pushf
        pop    %rax

%rax will contain the wrong value because the "lock neg" calculates the
wrong eflags.  Simple test:

        #include <assert.h>

        int main()
        {
          __volatile__ unsigned test = 0x2363a;
          __volatile__ char cond = 0;
          asm(
              "lock negl %0 \n\t"
              "sets %1"
              : "=m"(test), "=r"(cond));
          assert(cond & 1);
          return 0;
        }

Reported-by: Jinyang Shen <shenjinyang@loongson.cn>
Co-Developed-by: Xuehai Chen <chenxuehai@loongson.cn>
Signed-off-by: Xuehai Chen <chenxuehai@loongson.cn>
Signed-off-by: Qi Hu <huqi@loongson.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/tcg/translate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'target')

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 546c427c23..c477a10f41 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -3300,7 +3300,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
 
                 tcg_temp_free(t2);
                 tcg_temp_free(a0);
-                tcg_gen_mov_tl(s->T0, t0);
+                tcg_gen_neg_tl(s->T0, t0);
                 tcg_temp_free(t0);
             } else {
                 tcg_gen_neg_tl(s->T0, s->T0);
-- 
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