target/arm: Simplify GEN_SHIFT in translate.c

Instead of computing

    tmp1 = shift & 0xff;
    dest = (tmp1 > 0x1f ? 0 : value) << (tmp1 & 0x1f)

use

    tmpd = value << (shift & 0x1f);
    dest = shift & 0xe0 ? 0 : tmpd;

which has a flatter dependency tree.
Use tcg_constant_i32 while we're at it.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 4d7886fa853117ceface1c8143c65897dc96c42e..0c9d50d48df2993d284a65c70c1636a6af55d2cf 100644 (file)
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -552,16 +552,14 @@ static void gen_sbc_CC(TCGv_i32 dest, TCGv_i32 t0, TCGv_i32 t1)
 #define GEN_SHIFT(name)                                               \
 static void gen_##name(TCGv_i32 dest, TCGv_i32 t0, TCGv_i32 t1)       \
 {                                                                     \
-    TCGv_i32 tmp1, tmp2, tmp3;                                        \
-    tmp1 = tcg_temp_new_i32();                                        \
-    tcg_gen_andi_i32(tmp1, t1, 0xff);                                 \
-    tmp2 = tcg_const_i32(0);                                          \
-    tmp3 = tcg_const_i32(0x1f);                                       \
-    tcg_gen_movcond_i32(TCG_COND_GTU, tmp2, tmp1, tmp3, tmp2, t0);    \
-    tcg_temp_free_i32(tmp3);                                          \
-    tcg_gen_andi_i32(tmp1, tmp1, 0x1f);                               \
-    tcg_gen_##name##_i32(dest, tmp2, tmp1);                           \
-    tcg_temp_free_i32(tmp2);                                          \
+    TCGv_i32 tmpd = tcg_temp_new_i32();                               \
+    TCGv_i32 tmp1 = tcg_temp_new_i32();                               \
+    TCGv_i32 zero = tcg_constant_i32(0);                              \
+    tcg_gen_andi_i32(tmp1, t1, 0x1f);                                 \
+    tcg_gen_##name##_i32(tmpd, t0, tmp1);                             \
+    tcg_gen_andi_i32(tmp1, t1, 0xe0);                                 \
+    tcg_gen_movcond_i32(TCG_COND_NE, dest, tmp1, zero, zero, tmpd);   \
+    tcg_temp_free_i32(tmpd);                                          \
     tcg_temp_free_i32(tmp1);                                          \
 }
 GEN_SHIFT(shl)