From 367790cce8e14131426f5190dfd7d1bdbf656e4d Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 9 Nov 2016 14:46:09 +0100 Subject: [PATCH] target-m68k: Inline shifts Also manage word and byte operands and fix the computation of overflow in the case of M68000 arithmetic shifts. Signed-off-by: Laurent Vivier Signed-off-by: Richard Henderson Message-Id: <1478699171-10637-4-git-send-email-rth@twiddle.net> --- target/m68k/helper.c | 52 --------- target/m68k/helper.h | 3 - target/m68k/translate.c | 228 +++++++++++++++++++++++++++++++++++----- 3 files changed, 202 insertions(+), 81 deletions(-) diff --git a/target/m68k/helper.c b/target/m68k/helper.c index 7aed9ffd2f..f750d3dbaa 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 a6f88fca76..17ec342346 100644 --- a/target/m68k/helper.h +++ b/target/m68k/helper.h @@ -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) diff --git a/target/m68k/translate.c b/target/m68k/translate.c index 0417c325e6..76c77ee3e5 100644 --- a/target/m68k/translate.c +++ b/target/m68k/translate.c @@ -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. */ -DISAS_INSN(shift_im) +static inline void shift_im(DisasContext *s, uint16_t insn, int opsize) { - TCGv reg; - int tmp; - TCGv shift; + 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); - 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_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 { - 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); } } + + 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) +{ + shift_im(s, insn, OS_LONG); +} + +DISAS_INSN(shift8_reg) +{ + shift_reg(s, insn, OS_BYTE); +} + +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);