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authorAurelien Jarno <aurelien@aurel32.net>2012-09-26 19:38:43 +0100
committerPeter Maydell <peter.maydell@linaro.org>2012-09-26 19:38:43 +0100
commit418eeb8bfdd2dd52ef36ffa23e073ef85165c733 (patch)
tree83e2830fc755d5f9a7044069bc5611bb061e37e7
parentc21b38e36f86aaee101dead4845a896a0a73a213 (diff)
downloadqemu-arm-418eeb8bfdd2dd52ef36ffa23e073ef85165c733.tar.gz
target-arm: convert sar, shl and shr helpers to TCG
Now that the movcond TCG op is available, it's possible to replace shl and shr helpers by TCG code. The code generated by TCG is slightly longer than the code generated by GCC for the helper but is still worth it as this avoid all the consequences of using an helper: globals saved back to memory, no possible optimization, call overhead, etc. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target-arm/helper.h3
-rw-r--r--target-arm/op_helper.c24
-rw-r--r--target-arm/translate.c49
3 files changed, 43 insertions, 33 deletions
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 7151e28d4b..794e2b1869 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -145,9 +145,6 @@ DEF_HELPER_5(neon_tbl, i32, env, i32, i32, i32, i32)
DEF_HELPER_3(adc_cc, i32, env, i32, i32)
DEF_HELPER_3(sbc_cc, i32, env, i32, i32)
-DEF_HELPER_3(shl, i32, env, i32, i32)
-DEF_HELPER_3(shr, i32, env, i32, i32)
-DEF_HELPER_3(sar, i32, env, i32, i32)
DEF_HELPER_3(shl_cc, i32, env, i32, i32)
DEF_HELPER_3(shr_cc, i32, env, i32, i32)
DEF_HELPER_3(sar_cc, i32, env, i32, i32)
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index 6095f2435c..aef592ab8d 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -355,30 +355,6 @@ uint32_t HELPER(sbc_cc)(CPUARMState *env, uint32_t a, uint32_t b)
/* Similarly for variable shift instructions. */
-uint32_t HELPER(shl)(CPUARMState *env, uint32_t x, uint32_t i)
-{
- int shift = i & 0xff;
- if (shift >= 32)
- return 0;
- return x << shift;
-}
-
-uint32_t HELPER(shr)(CPUARMState *env, uint32_t x, uint32_t i)
-{
- int shift = i & 0xff;
- if (shift >= 32)
- return 0;
- return (uint32_t)x >> shift;
-}
-
-uint32_t HELPER(sar)(CPUARMState *env, uint32_t x, uint32_t i)
-{
- int shift = i & 0xff;
- if (shift >= 32)
- shift = 31;
- return (int32_t)x >> shift;
-}
-
uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i)
{
int shift = i & 0xff;
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 19bb1e8da1..953a80e91a 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -440,6 +440,37 @@ static void gen_sub_CC(TCGv dest, TCGv t0, TCGv t1)
tcg_gen_mov_i32(dest, cpu_NF);
}
+#define GEN_SHIFT(name) \
+static void gen_##name(TCGv dest, TCGv t0, TCGv t1) \
+{ \
+ TCGv 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); \
+ tcg_temp_free_i32(tmp1); \
+}
+GEN_SHIFT(shl)
+GEN_SHIFT(shr)
+#undef GEN_SHIFT
+
+static void gen_sar(TCGv dest, TCGv t0, TCGv t1)
+{
+ TCGv tmp1, tmp2;
+ tmp1 = tcg_temp_new_i32();
+ tcg_gen_andi_i32(tmp1, t1, 0xff);
+ tmp2 = tcg_const_i32(0x1f);
+ tcg_gen_movcond_i32(TCG_COND_GTU, tmp1, tmp1, tmp2, tmp2, tmp1);
+ tcg_temp_free_i32(tmp2);
+ tcg_gen_sar_i32(dest, t0, tmp1);
+ tcg_temp_free_i32(tmp1);
+}
+
/* FIXME: Implement this natively. */
#define tcg_gen_abs_i32(t0, t1) gen_helper_abs(t0, t1)
@@ -516,9 +547,15 @@ static inline void gen_arm_shift_reg(TCGv var, int shiftop,
}
} else {
switch (shiftop) {
- case 0: gen_helper_shl(var, cpu_env, var, shift); break;
- case 1: gen_helper_shr(var, cpu_env, var, shift); break;
- case 2: gen_helper_sar(var, cpu_env, var, shift); break;
+ case 0:
+ gen_shl(var, var, shift);
+ break;
+ case 1:
+ gen_shr(var, var, shift);
+ break;
+ case 2:
+ gen_sar(var, var, shift);
+ break;
case 3: tcg_gen_andi_i32(shift, shift, 0x1f);
tcg_gen_rotr_i32(var, var, shift); break;
}
@@ -9161,7 +9198,7 @@ static void disas_thumb_insn(CPUARMState *env, DisasContext *s)
break;
case 0x2: /* lsl */
if (s->condexec_mask) {
- gen_helper_shl(tmp2, cpu_env, tmp2, tmp);
+ gen_shl(tmp2, tmp2, tmp);
} else {
gen_helper_shl_cc(tmp2, cpu_env, tmp2, tmp);
gen_logic_CC(tmp2);
@@ -9169,7 +9206,7 @@ static void disas_thumb_insn(CPUARMState *env, DisasContext *s)
break;
case 0x3: /* lsr */
if (s->condexec_mask) {
- gen_helper_shr(tmp2, cpu_env, tmp2, tmp);
+ gen_shr(tmp2, tmp2, tmp);
} else {
gen_helper_shr_cc(tmp2, cpu_env, tmp2, tmp);
gen_logic_CC(tmp2);
@@ -9177,7 +9214,7 @@ static void disas_thumb_insn(CPUARMState *env, DisasContext *s)
break;
case 0x4: /* asr */
if (s->condexec_mask) {
- gen_helper_sar(tmp2, cpu_env, tmp2, tmp);
+ gen_sar(tmp2, tmp2, tmp);
} else {
gen_helper_sar_cc(tmp2, cpu_env, tmp2, tmp);
gen_logic_CC(tmp2);