drc, tiny x86 optimisation

diff --git a/cpu/drc/emit_x86.c b/cpu/drc/emit_x86.c
index 94111e0..3ef2ed6 100644 (file)
--- a/cpu/drc/emit_x86.c
+++ b/cpu/drc/emit_x86.c
@@ -519,15 +519,23 @@ enum { xAX = 0, xCX, xDX, xBX, xSP, xBP, xSI, xDI,        // x86-64,i386 common
 
 // _r_r_imm - use lea
 #define emith_add_r_r_imm(d, s, imm) do { \
-       EMIT_REX_IF(0, d, s); \
-       emith_deref_modrm(0x8d, 2, d, s); \
-       EMIT(imm, s32); \
+       if (imm == 0) \
+               emith_move_r_r(d, s); \
+       else { \
+               EMIT_REX_IF(0, d, s); \
+               emith_deref_modrm(0x8d, 2, d, s); \
+               EMIT(imm, s32); \
+       } \
 } while (0)
 
 #define emith_add_r_r_ptr_imm(d, s, imm) do { \
-       EMIT_REX_IF(1, d, s); \
-       emith_deref_modrm(0x8d, 2, d, s); \
-       EMIT(imm, s32); \
+       if (imm == 0) \
+               emith_move_r_r_ptr(d, s); \
+       else { \
+               EMIT_REX_IF(1, d, s); \
+               emith_deref_modrm(0x8d, 2, d, s); \
+               EMIT(imm, s32); \
+       } \
 } while (0)
 
 #define emith_sub_r_r_imm(d, s, imm) do { \