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target-m68k: Inline shifts

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Also manage word and byte operands and fix the computation of
overflow in the case of M68000 arithmetic shifts.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1478699171-10637-4-git-send-email-rth@twiddle.net>
This commit is contained in:
Richard Henderson 2016-11-09 14:46:09 +01:00 committed by Laurent Vivier
parent 72d2e4b6a4
commit 367790cce8
3 changed files with 202 additions and 81 deletions
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52
target/m68k/helper.c
View File

@ -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)
{

3
target/m68k/helper.h
View File

@ -7,9 +7,6 @@ DEF_HELPER_4(divul, void, env, int, int, i32)
DEF_HELPER_4(divsl, void, env, int, int, s32)
DEF_HELPER_4(divull, void, env, int, int, i32)
DEF_HELPER_4(divsll, void, env, int, int, s32)
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)
DEF_HELPER_4(cas2w, void, env, i32, i32, i32)

234
target/m68k/translate.c
View File

@ -2883,48 +2883,217 @@ DISAS_INSN(addx_mem)
gen_store(s, opsize, addr_dest, QREG_CC_N);
}
/* TODO: This could be implemented without helper functions. */
static inline void shift_im(DisasContext *s, uint16_t insn, int opsize)
{
int count = (insn >> 9) & 7;
int logical = insn & 8;
int left = insn & 0x100;
int bits = opsize_bytes(opsize) * 8;
TCGv reg = gen_extend(DREG(insn, 0), opsize, !logical);
if (count == 0) {
count = 8;
}
tcg_gen_movi_i32(QREG_CC_V, 0);
if (left) {
tcg_gen_shri_i32(QREG_CC_C, reg, bits - count);
tcg_gen_shli_i32(QREG_CC_N, reg, count);
/* Note that ColdFire always clears V (done above),
while M68000 sets if the most significant bit is changed at
any time during the shift operation */
if (!logical && m68k_feature(s->env, M68K_FEATURE_M68000)) {
/* if shift count >= bits, V is (reg != 0) */
if (count >= bits) {
tcg_gen_setcond_i32(TCG_COND_NE, QREG_CC_V, reg, QREG_CC_V);
} else {
TCGv t0 = tcg_temp_new();
tcg_gen_sari_i32(QREG_CC_V, reg, bits - 1);
tcg_gen_sari_i32(t0, reg, bits - count - 1);
tcg_gen_setcond_i32(TCG_COND_NE, QREG_CC_V, QREG_CC_V, t0);
tcg_temp_free(t0);
}
tcg_gen_neg_i32(QREG_CC_V, QREG_CC_V);
}
} else {
tcg_gen_shri_i32(QREG_CC_C, reg, count - 1);
if (logical) {
tcg_gen_shri_i32(QREG_CC_N, reg, count);
} else {
tcg_gen_sari_i32(QREG_CC_N, reg, count);
}
}
gen_ext(QREG_CC_N, QREG_CC_N, opsize, 1);
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);
gen_partset_reg(opsize, DREG(insn, 0), QREG_CC_N);
set_cc_op(s, CC_OP_FLAGS);
}
static inline void shift_reg(DisasContext *s, uint16_t insn, int opsize)
{
int logical = insn & 8;
int left = insn & 0x100;
int bits = opsize_bytes(opsize) * 8;
TCGv reg = gen_extend(DREG(insn, 0), opsize, !logical);
TCGv s32;
TCGv_i64 t64, s64;
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);
tcg_gen_extu_i32_i64(t64, reg);
/* Optimistically set V=0. Also used as a zero source below. */
tcg_gen_movi_i32(QREG_CC_V, 0);
if (left) {
tcg_gen_shl_i64(t64, t64, s64);
if (opsize == OS_LONG) {
tcg_gen_extr_i64_i32(QREG_CC_N, QREG_CC_C, t64);
/* Note that C=0 if shift count is 0, and we get that for free. */
} else {
TCGv zero = tcg_const_i32(0);
tcg_gen_extrl_i64_i32(QREG_CC_N, t64);
tcg_gen_shri_i32(QREG_CC_C, QREG_CC_N, bits);
tcg_gen_movcond_i32(TCG_COND_EQ, QREG_CC_C,
s32, zero, zero, QREG_CC_C);
tcg_temp_free(zero);
}
tcg_gen_andi_i32(QREG_CC_C, QREG_CC_C, 1);
/* 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);
/* M68000 sets V if the most significant bit is changed at
* any time during the shift operation. Do this via creating
* an extension of the sign bit, comparing, and discarding
* the bits below the sign bit. I.e.
* int64_t s = (intN_t)reg;
* int64_t t = (int64_t)(intN_t)reg << count;
* V = ((s ^ t) & (-1 << (bits - 1))) != 0
*/
if (!logical && m68k_feature(s->env, M68K_FEATURE_M68000)) {
TCGv_i64 tt = tcg_const_i64(32);
/* if shift is greater than 32, use 32 */
tcg_gen_movcond_i64(TCG_COND_GT, s64, s64, tt, tt, s64);
tcg_temp_free_i64(tt);
/* Sign extend the input to 64 bits; re-do the shift. */
tcg_gen_ext_i32_i64(t64, reg);
tcg_gen_shl_i64(s64, t64, s64);
/* Clear all bits that are unchanged. */
tcg_gen_xor_i64(t64, t64, s64);
/* Ignore the bits below the sign bit. */
tcg_gen_andi_i64(t64, t64, -1ULL << (bits - 1));
/* If any bits remain set, we have overflow. */
tcg_gen_setcondi_i64(TCG_COND_NE, t64, t64, 0);
tcg_gen_extrl_i64_i32(QREG_CC_V, t64);
tcg_gen_neg_i32(QREG_CC_V, QREG_CC_V);
}
} else {
tcg_gen_shli_i64(t64, t64, 32);
if (logical) {
tcg_gen_shr_i64(t64, t64, s64);
} else {
tcg_gen_sar_i64(t64, t64, s64);
}
tcg_gen_extr_i64_i32(QREG_CC_C, QREG_CC_N, t64);
/* Note that C=0 if shift count is 0, and we get that for free. */
tcg_gen_shri_i32(QREG_CC_C, QREG_CC_C, 31);
/* 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);
}
gen_ext(QREG_CC_N, QREG_CC_N, opsize, 1);
tcg_gen_mov_i32(QREG_CC_Z, QREG_CC_N);
tcg_temp_free(s32);
tcg_temp_free_i64(s64);
tcg_temp_free_i64(t64);
/* Write back the result. */
gen_partset_reg(opsize, DREG(insn, 0), QREG_CC_N);
set_cc_op(s, CC_OP_FLAGS);
}
DISAS_INSN(shift8_im)
{
shift_im(s, insn, OS_BYTE);
}
DISAS_INSN(shift16_im)
{
shift_im(s, insn, OS_WORD);
}
DISAS_INSN(shift_im)
{
TCGv reg;
int tmp;
TCGv shift;
shift_im(s, insn, OS_LONG);
}
set_cc_op(s, CC_OP_FLAGS);
DISAS_INSN(shift8_reg)
{
shift_reg(s, insn, OS_BYTE);
}
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);
} else {
if (insn & 8) {
gen_helper_shr_cc(reg, cpu_env, reg, shift);
} else {
gen_helper_sar_cc(reg, cpu_env, reg, shift);
}
}
DISAS_INSN(shift16_reg)
{
shift_reg(s, insn, OS_WORD);
}
DISAS_INSN(shift_reg)
{
TCGv reg;
TCGv shift;
shift_reg(s, insn, OS_LONG);
}
reg = DREG(insn, 0);
shift = DREG(insn, 9);
if (insn & 0x100) {
gen_helper_shl_cc(reg, cpu_env, reg, shift);
DISAS_INSN(shift_mem)
{
int logical = insn & 8;
int left = insn & 0x100;
TCGv src;
TCGv addr;
SRC_EA(env, src, OS_WORD, !logical, &addr);
tcg_gen_movi_i32(QREG_CC_V, 0);
if (left) {
tcg_gen_shri_i32(QREG_CC_C, src, 15);
tcg_gen_shli_i32(QREG_CC_N, src, 1);
/* Note that ColdFire always clears V,
while M68000 sets if the most significant bit is changed at
any time during the shift operation */
if (!logical && m68k_feature(s->env, M68K_FEATURE_M68000)) {
src = gen_extend(src, OS_WORD, 1);
tcg_gen_xor_i32(QREG_CC_V, QREG_CC_N, src);
}
} else {
if (insn & 8) {
gen_helper_shr_cc(reg, cpu_env, reg, shift);
tcg_gen_mov_i32(QREG_CC_C, src);
if (logical) {
tcg_gen_shri_i32(QREG_CC_N, src, 1);
} else {
gen_helper_sar_cc(reg, cpu_env, reg, shift);
tcg_gen_sari_i32(QREG_CC_N, src, 1);
}
}
gen_ext(QREG_CC_N, QREG_CC_N, OS_WORD, 1);
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);
DEST_EA(env, insn, OS_WORD, QREG_CC_N, &addr);
set_cc_op(s, CC_OP_FLAGS);
}
@ -4005,6 +4174,13 @@ void register_m68k_insns (CPUM68KState *env)
INSN(adda, d0c0, f0c0, M68000);
INSN(shift_im, e080, f0f0, CF_ISA_A);
INSN(shift_reg, e0a0, f0f0, CF_ISA_A);
INSN(shift8_im, e000, f0f0, M68000);
INSN(shift16_im, e040, f0f0, M68000);
INSN(shift_im, e080, f0f0, M68000);
INSN(shift8_reg, e020, f0f0, M68000);
INSN(shift16_reg, e060, f0f0, M68000);
INSN(shift_reg, e0a0, f0f0, M68000);
INSN(shift_mem, e0c0, fcc0, M68000);
INSN(undef_fpu, f000, f000, CF_ISA_A);
INSN(fpu, f200, ffc0, CF_FPU);
INSN(fbcc, f280, ffc0, CF_FPU);