[Qemu-devel] [PATCH 5/5] target-m68k: increment/decrement with SP

[Laurent Vivier <laurent@vivier.eu>]

Address Register indirect With postincrement:

When using the stack pointer (A7) with byte size data, the register
is incremented by two.

Address Register indirect With predecrement:

When using the stack pointer (A7) with byte size data, the register
is decremented by two.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 target/m68k/translate.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index cf5d8dd..c83d902 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -725,7 +725,10 @@ static TCGv gen_lea_mode(CPUM68KState *env, DisasContext *s,
         }
         reg = get_areg(s, reg0);
         tmp = tcg_temp_new();
-        tcg_gen_subi_i32(tmp, reg, opsize_bytes(opsize));
+        tcg_gen_subi_i32(tmp, reg,
+                         reg0 == 7 && opsize == OS_BYTE
+                         ? 2
+                         : opsize_bytes(opsize));
         return tmp;
     case 5: /* Indirect displacement.  */
         reg = get_areg(s, reg0);
@@ -801,7 +804,10 @@ static TCGv gen_ea_mode(CPUM68KState *env, DisasContext *s, int mode, int reg0,
         result = gen_ldst(s, opsize, reg, val, what);
         if (what == EA_STORE || !addrp) {
             TCGv tmp = tcg_temp_new();
-            tcg_gen_addi_i32(tmp, reg, opsize_bytes(opsize));
+            tcg_gen_addi_i32(tmp, reg,
+                             reg0 == 7 && opsize == OS_BYTE
+                             ? 2
+                             : opsize_bytes(opsize));
             delay_set_areg(s, reg0, tmp, true);
         }
         return result;
-- 
2.7.4