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Diffstat (limited to 'target/m68k/translate.c')
-rw-r--r--target/m68k/translate.c226
1 files changed, 201 insertions, 25 deletions
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);
+
+ 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);
+}
- 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);
+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 {
- if (insn & 8) {
- gen_helper_shr_cc(reg, cpu_env, reg, shift);
+ 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_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);
generated by cgit v1.2.3 (git 2.26.2) at 2025-01-04 01:41:18 +0000