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[Qemu-devel] [PATCH 2/3] target-m68k: Inline shifts
From: |
Laurent Vivier |
Subject: |
[Qemu-devel] [PATCH 2/3] target-m68k: Inline shifts |
Date: |
Thu, 27 Oct 2016 21:09:53 +0200 |
From: Richard Henderson <address@hidden>
Original patch from Richard Henderson <address@hidden>
Fix arithmetical/logical switch
Signed-off-by: Laurent Vivier <address@hidden>
---
target-m68k/helper.c | 52 ---------------------------
target-m68k/helper.h | 3 --
target-m68k/translate.c | 96 +++++++++++++++++++++++++++++++++++++------------
3 files changed, 73 insertions(+), 78 deletions(-)
diff --git a/target-m68k/helper.c b/target-m68k/helper.c
index 7aed9ff..f750d3d 100644
--- a/target-m68k/helper.c
+++ b/target-m68k/helper.c
@@ -284,58 +284,6 @@ void HELPER(set_sr)(CPUM68KState *env, uint32_t val)
m68k_switch_sp(env);
}
-uint32_t HELPER(shl_cc)(CPUM68KState *env, uint32_t val, uint32_t shift)
-{
- uint64_t result;
-
- shift &= 63;
- result = (uint64_t)val << shift;
-
- env->cc_c = (result >> 32) & 1;
- env->cc_n = result;
- env->cc_z = result;
- env->cc_v = 0;
- env->cc_x = shift ? env->cc_c : env->cc_x;
-
- return result;
-}
-
-uint32_t HELPER(shr_cc)(CPUM68KState *env, uint32_t val, uint32_t shift)
-{
- uint64_t temp;
- uint32_t result;
-
- shift &= 63;
- temp = (uint64_t)val << 32 >> shift;
- result = temp >> 32;
-
- env->cc_c = (temp >> 31) & 1;
- env->cc_n = result;
- env->cc_z = result;
- env->cc_v = 0;
- env->cc_x = shift ? env->cc_c : env->cc_x;
-
- return result;
-}
-
-uint32_t HELPER(sar_cc)(CPUM68KState *env, uint32_t val, uint32_t shift)
-{
- uint64_t temp;
- uint32_t result;
-
- shift &= 63;
- temp = (int64_t)val << 32 >> shift;
- result = temp >> 32;
-
- env->cc_c = (temp >> 31) & 1;
- env->cc_n = result;
- env->cc_z = result;
- env->cc_v = result ^ val;
- env->cc_x = shift ? env->cc_c : env->cc_x;
-
- return result;
-}
-
/* FPU helpers. */
uint32_t HELPER(f64_to_i32)(CPUM68KState *env, float64 val)
{
diff --git a/target-m68k/helper.h b/target-m68k/helper.h
index 2697e32..aae01f9 100644
--- a/target-m68k/helper.h
+++ b/target-m68k/helper.h
@@ -3,9 +3,6 @@ DEF_HELPER_1(ff1, i32, i32)
DEF_HELPER_FLAGS_2(sats, TCG_CALL_NO_RWG_SE, i32, i32, i32)
DEF_HELPER_2(divu, void, env, i32)
DEF_HELPER_2(divs, void, env, 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)
DEF_HELPER_2(set_sr, void, env, i32)
DEF_HELPER_3(movec, void, env, i32, i32)
diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index 92e67eb..13ef117 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -562,7 +562,7 @@ static void gen_flush_flags(DisasContext *s)
s->cc_op_synced = 1;
}
-static inline TCGv gen_extend(TCGv val, int opsize, int sign)
+static TCGv gen_extend(TCGv val, int opsize, int sign)
{
TCGv tmp;
@@ -2348,48 +2348,98 @@ DISAS_INSN(addx_mem)
gen_store(s, opsize, addr_dest, QREG_CC_N);
}
-/* TODO: This could be implemented without helper functions. */
DISAS_INSN(shift_im)
{
- TCGv reg;
- int tmp;
- TCGv shift;
+ TCGv reg = DREG(insn, 0);
+ int count = (insn >> 9) & 7;
+ int logical = insn & 8;
- set_cc_op(s, CC_OP_FLAGS);
+ if (count == 0) {
+ count = 8;
+ }
- reg = DREG(insn, 0);
- tmp = (insn >> 9) & 7;
- if (tmp == 0)
- tmp = 8;
- shift = tcg_const_i32(tmp);
- /* No need to flush flags becuse we know we will set C flag. */
if (insn & 0x100) {
- gen_helper_shl_cc(reg, cpu_env, reg, shift);
+ tcg_gen_shri_i32(QREG_CC_C, reg, 31 - count);
+ tcg_gen_shli_i32(QREG_CC_N, reg, count);
} else {
- if (insn & 8) {
- gen_helper_shr_cc(reg, cpu_env, reg, shift);
+ tcg_gen_shri_i32(QREG_CC_C, reg, count - 1);
+ if (logical) {
+ tcg_gen_shri_i32(QREG_CC_N, reg, count);
} else {
- gen_helper_sar_cc(reg, cpu_env, reg, shift);
+ tcg_gen_sari_i32(QREG_CC_N, reg, count);
}
}
+ tcg_gen_andi_i32(QREG_CC_C, QREG_CC_C, 1);
+ tcg_gen_mov_i32(QREG_CC_Z, QREG_CC_N);
+ tcg_gen_mov_i32(QREG_CC_X, QREG_CC_C);
+
+ /* Note that ColdFire always clears V, while M68000 sets it for
+ a change in the sign bit. */
+ if (!logical && m68k_feature(s->env, M68K_FEATURE_M68000)) {
+ tcg_gen_xor_i32(QREG_CC_V, QREG_CC_N, reg);
+ } else {
+ tcg_gen_movi_i32(QREG_CC_V, 0);
+ }
+
+ tcg_gen_mov_i32(reg, QREG_CC_N);
+ set_cc_op(s, CC_OP_FLAGS);
}
DISAS_INSN(shift_reg)
{
- TCGv reg;
- TCGv shift;
+ TCGv reg, s32;
+ TCGv_i64 t64, s64;
+ int logical = insn & 8;
reg = DREG(insn, 0);
- shift = DREG(insn, 9);
+ t64 = tcg_temp_new_i64();
+ s64 = tcg_temp_new_i64();
+ s32 = tcg_temp_new();
+
+ /* Note that m68k truncates the shift count modulo 64, not 32.
+ In addition, a 64-bit shift makes it easy to find "the last
+ bit shifted out", for the carry flag. */
+ tcg_gen_andi_i32(s32, DREG(insn, 9), 63);
+ tcg_gen_extu_i32_i64(s64, s32);
+
+ /* Non-arithmetic shift clears V. Use it as a source zero here. */
+ tcg_gen_movi_i32(QREG_CC_V, 0);
+
if (insn & 0x100) {
- gen_helper_shl_cc(reg, cpu_env, reg, shift);
+ tcg_gen_extu_i32_i64(t64, reg);
+ tcg_gen_shl_i64(t64, t64, s64);
+ tcg_temp_free_i64(s64);
+ tcg_gen_extr_i64_i32(QREG_CC_N, QREG_CC_C, t64);
+ tcg_temp_free_i64(t64);
+ tcg_gen_andi_i32(QREG_CC_C, QREG_CC_C, 1);
} else {
- if (insn & 8) {
- gen_helper_shr_cc(reg, cpu_env, reg, shift);
+ tcg_gen_extu_i32_i64(t64, reg);
+ tcg_gen_shli_i64(t64, t64, 32);
+ if (logical) {
+ tcg_gen_shr_i64(t64, t64, s64);
} else {
- gen_helper_sar_cc(reg, cpu_env, reg, shift);
+ tcg_gen_sar_i64(t64, t64, s64);
}
+ tcg_temp_free_i64(s64);
+ tcg_gen_extr_i64_i32(QREG_CC_C, QREG_CC_N, t64);
+ tcg_temp_free_i64(t64);
+ tcg_gen_shri_i32(QREG_CC_C, QREG_CC_C, 31);
}
+ tcg_gen_mov_i32(QREG_CC_Z, QREG_CC_N);
+
+ /* Note that X = C, but only if the shift count was non-zero. */
+ tcg_gen_movcond_i32(TCG_COND_NE, QREG_CC_X, s32, QREG_CC_V,
+ QREG_CC_C, QREG_CC_X);
+ tcg_temp_free(s32);
+
+ /* Note that ColdFire always clears V (which we have done above),
+ while M68000 sets it for a change in the sign bit. */
+ if (!logical && m68k_feature(s->env, M68K_FEATURE_M68000)) {
+ tcg_gen_xor_i32(QREG_CC_V, QREG_CC_N, reg);
+ }
+
+ /* Write back the result. */
+ tcg_gen_mov_i32(reg, QREG_CC_N);
set_cc_op(s, CC_OP_FLAGS);
}
--
2.7.4