target/m68k: Always return a temporary from gen_lea_mode

Returning a raw areg does not preserve the value if the areg
is subsequently modified.  Fixes, e.g. "jsr (sp)", where the
return address is pushed before the branch.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2483
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240813000737.228470-1-richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
(cherry picked from commit 352cc9f300d83ea48b8154bfd2ff985fece887d0)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 8a194f2f2134fb6263f9df7f3235e685c2b5b822..f2420b92e14c16098b99666ecbde26ce81f10b09 100644 (file)
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -722,7 +722,9 @@ static TCGv gen_lea_mode(CPUM68KState *env, DisasContext *s,
         }
         /* fallthru */
     case 2: /* Indirect register */
-        return get_areg(s, reg0);
+        tmp = tcg_temp_new();
+        tcg_gen_mov_i32(tmp, get_areg(s, reg0));
+        return tmp;
     case 4: /* Indirect predecrememnt.  */
         if (opsize == OS_UNSIZED) {
             return NULL_QREG;
@@ -749,20 +751,23 @@ static TCGv gen_lea_mode(CPUM68KState *env, DisasContext *s,
         switch (reg0) {
         case 0: /* Absolute short.  */
             offset = (int16_t)read_im16(env, s);
-            return tcg_constant_i32(offset);
+            break;
         case 1: /* Absolute long.  */
             offset = read_im32(env, s);
-            return tcg_constant_i32(offset);
+            break;
         case 2: /* pc displacement  */
             offset = s->pc;
             offset += (int16_t)read_im16(env, s);
-            return tcg_constant_i32(offset);
+            break;
         case 3: /* pc index+displacement.  */
             return gen_lea_indexed(env, s, NULL_QREG);
         case 4: /* Immediate.  */
         default:
             return NULL_QREG;
         }
+        tmp = tcg_temp_new();
+        tcg_gen_movi_i32(tmp, offset);
+        return tmp;
     }
     /* Should never happen.  */
     return NULL_QREG;