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-rw-r--r--gen_x86.c9
-rw-r--r--gen_x86.h1
-rw-r--r--m68k_to_x86.c139
-rw-r--r--runtime.S8
4 files changed, 110 insertions, 47 deletions
diff --git a/gen_x86.c b/gen_x86.c
index 1f87329..2deb864 100644
--- a/gen_x86.c
+++ b/gen_x86.c
@@ -35,6 +35,7 @@
#define OP_MOV_IEA 0xC6
#define OP_SHIFTROT_1 0xD0
#define OP_SHIFTROT_CL 0xD2
+#define OP_LOOP 0xE2
#define OP_CALL 0xE8
#define OP_JMP 0xE9
#define OP_JMP_BYTE 0xEB
@@ -1533,4 +1534,10 @@ uint8_t * cdq(uint8_t * out)
return out;
}
-
+uint8_t * loop(uint8_t * out, uint8_t * dst)
+{
+ ptrdiff_t disp = dst-(out+2);
+ *(out++) = OP_LOOP;
+ *(out++) = disp;
+ return out;
+}
diff --git a/gen_x86.h b/gen_x86.h
index f3c4871..f5d2313 100644
--- a/gen_x86.h
+++ b/gen_x86.h
@@ -190,6 +190,7 @@ uint8_t * call(uint8_t * out, uint8_t * fun);
uint8_t * call_r(uint8_t * out, uint8_t dst);
uint8_t * retn(uint8_t * out);
uint8_t * cdq(uint8_t * out);
+uint8_t * loop(uint8_t * out, uint8_t * dst);
#endif //GEN_X86_H_
diff --git a/m68k_to_x86.c b/m68k_to_x86.c
index 377c0da..d700ac7 100644
--- a/m68k_to_x86.c
+++ b/m68k_to_x86.c
@@ -92,7 +92,7 @@ size_t reg_offset(m68k_op_info *op)
void print_regs_exit(m68k_context * context)
{
- printf("XNVZC\n%d%d%d%d%d\n", context->flags[0], context->flags[1], context->flags[2], context->flags[3], context->flags[4]);
+ printf("XNZVC\n%d%d%d%d%d\n", context->flags[0], context->flags[1], context->flags[2], context->flags[3], context->flags[4]);
for (int i = 0; i < 8; i++) {
printf("d%d: %X\n", i, context->dregs[i]);
}
@@ -2619,6 +2619,8 @@ typedef uint8_t * (*shift_clrdisp8_t)(uint8_t * out, uint8_t dst_base, int8_t di
uint8_t * translate_shift(uint8_t * dst, m68kinst * inst, x86_ea *src_op, x86_ea * dst_op, x86_68k_options * opts, shift_ir_t shift_ir, shift_irdisp8_t shift_irdisp8, shift_clr_t shift_clr, shift_clrdisp8_t shift_clrdisp8, shift_ir_t special, shift_irdisp8_t special_disp8)
{
uint8_t * end_off = NULL;
+ uint8_t * nz_off = NULL;
+ uint8_t * z_off = NULL;
if (inst->src.addr_mode == MODE_UNUSED) {
dst = cycles(dst, BUS);
//Memory shift
@@ -2626,10 +2628,24 @@ uint8_t * translate_shift(uint8_t * dst, m68kinst * inst, x86_ea *src_op, x86_ea
} else {
dst = cycles(dst, inst->extra.size == OPSIZE_LONG ? 8 : 6);
if (src_op->mode == MODE_IMMED) {
- if (dst_op->mode == MODE_REG_DIRECT) {
- dst = shift_ir(dst, src_op->disp, dst_op->base, inst->extra.size);
+ if (src_op->disp != 1 && inst->op == M68K_ASL) {
+ dst = mov_ir(dst, 0, FLAG_V, SZ_B);
+ for (int i = 0; i < src_op->disp; i++) {
+ if (dst_op->mode == MODE_REG_DIRECT) {
+ dst = shift_ir(dst, 1, dst_op->base, inst->extra.size);
+ } else {
+ dst = shift_irdisp8(dst, 1, dst_op->base, dst_op->disp, inst->extra.size);
+ }
+ //dst = setcc_r(dst, CC_O, FLAG_V);
+ dst = jcc(dst, CC_NO, dst+4);
+ dst = mov_ir(dst, 1, FLAG_V, SZ_B);
+ }
} else {
- dst = shift_irdisp8(dst, src_op->disp, dst_op->base, dst_op->disp, inst->extra.size);
+ if (dst_op->mode == MODE_REG_DIRECT) {
+ dst = shift_ir(dst, src_op->disp, dst_op->base, inst->extra.size);
+ } else {
+ dst = shift_irdisp8(dst, src_op->disp, dst_op->base, dst_op->disp, inst->extra.size);
+ }
}
} else {
if (src_op->base != RCX) {
@@ -2638,58 +2654,92 @@ uint8_t * translate_shift(uint8_t * dst, m68kinst * inst, x86_ea *src_op, x86_ea
} else {
dst = mov_rdisp8r(dst, src_op->base, src_op->disp, RCX, SZ_B);
}
+
}
dst = and_ir(dst, 63, RCX, SZ_D);
+ nz_off = dst+1;
+ dst = jcc(dst, CC_NZ, dst+2);
+ //Flag behavior for shift count of 0 is different for x86 than 68K
+ if (dst_op->mode == MODE_REG_DIRECT) {
+ dst = cmp_ir(dst, 0, dst_op->base, inst->extra.size);
+ } else {
+ dst = cmp_irdisp8(dst, 0, dst_op->base, dst_op->disp, inst->extra.size);
+ }
+ dst = setcc_r(dst, CC_Z, FLAG_Z);
+ dst = setcc_r(dst, CC_S, FLAG_N);
+ dst = mov_ir(dst, 0, FLAG_C, SZ_B);
+ //For other instructions, this flag will be set below
+ if (inst->op == M68K_ASL) {
+ dst = mov_ir(dst, 0, FLAG_V, SZ_B);
+ }
+ z_off = dst+1;
+ dst = jmp(dst, dst+2);
+ *nz_off = dst - (nz_off + 1);
//add 2 cycles for every bit shifted
dst = add_rr(dst, RCX, CYCLES, SZ_D);
dst = add_rr(dst, RCX, CYCLES, SZ_D);
- //x86 shifts modulo 32 for operand sizes less than 64-bits
- //but M68K shifts modulo 64, so we need to check for large shifts here
- dst = cmp_ir(dst, 32, RCX, SZ_B);
- uint8_t * norm_shift_off = dst + 1;
- dst = jcc(dst, CC_L, dst+2);
- if (special) {
- if (inst->extra.size == OPSIZE_LONG) {
- uint8_t * neq_32_off = dst + 1;
- dst = jcc(dst, CC_NZ, dst+2);
+ if (inst->op == M68K_ASL) {
+ //ASL has Overflow flag behavior that depends on all of the bits shifted through the MSB
+ //Easiest way to deal with this is to shift one bit at a time
+ dst = mov_ir(dst, 0, FLAG_V, SZ_B);
+ uint8_t * loop_start = dst;
+ if (dst_op->mode == MODE_REG_DIRECT) {
+ dst = shift_ir(dst, 1, dst_op->base, inst->extra.size);
+ } else {
+ dst = shift_irdisp8(dst, 1, dst_op->base, dst_op->disp, inst->extra.size);
+ }
+ //dst = setcc_r(dst, CC_O, FLAG_V);
+ dst = jcc(dst, CC_NO, dst+4);
+ dst = mov_ir(dst, 1, FLAG_V, SZ_B);
+ dst = loop(dst, loop_start);
+ } else {
+ //x86 shifts modulo 32 for operand sizes less than 64-bits
+ //but M68K shifts modulo 64, so we need to check for large shifts here
+ dst = cmp_ir(dst, 32, RCX, SZ_B);
+ uint8_t * norm_shift_off = dst + 1;
+ dst = jcc(dst, CC_L, dst+2);
+ if (special) {
+ if (inst->extra.size == OPSIZE_LONG) {
+ uint8_t * neq_32_off = dst + 1;
+ dst = jcc(dst, CC_NZ, dst+2);
- //set the carry bit to the lsb
+ //set the carry bit to the lsb
+ if (dst_op->mode == MODE_REG_DIRECT) {
+ dst = special(dst, 1, dst_op->base, SZ_D);
+ } else {
+ dst = special_disp8(dst, 1, dst_op->base, dst_op->disp, SZ_D);
+ }
+ dst = setcc_r(dst, CC_C, FLAG_C);
+ dst = jmp(dst, dst+4);
+ *neq_32_off = dst - (neq_32_off+1);
+ }
+ dst = mov_ir(dst, 0, FLAG_C, SZ_B);
+ dst = mov_ir(dst, 1, FLAG_Z, SZ_B);
+ dst = mov_ir(dst, 0, FLAG_N, SZ_B);
if (dst_op->mode == MODE_REG_DIRECT) {
- dst = special(dst, 1, dst_op->base, SZ_D);
+ dst = xor_rr(dst, dst_op->base, dst_op->base, inst->extra.size);
} else {
- dst = special_disp8(dst, 1, dst_op->base, dst_op->disp, SZ_D);
+ dst = mov_irdisp8(dst, 0, dst_op->base, dst_op->disp, inst->extra.size);
}
- dst = setcc_r(dst, CC_C, FLAG_C);
- dst = jmp(dst, dst+4);
- *neq_32_off = dst - (neq_32_off+1);
- }
- dst = mov_ir(dst, 0, FLAG_C, SZ_B);
- dst = mov_ir(dst, 1, FLAG_Z, SZ_B);
- dst = mov_ir(dst, 0, FLAG_N, SZ_B);
- if (dst_op->mode == MODE_REG_DIRECT) {
- dst = xor_rr(dst, dst_op->base, dst_op->base, inst->extra.size);
} else {
- dst = mov_irdisp8(dst, 0, dst_op->base, dst_op->disp, inst->extra.size);
+ if (dst_op->mode == MODE_REG_DIRECT) {
+ dst = shift_ir(dst, 31, dst_op->base, inst->extra.size);
+ dst = shift_ir(dst, 1, dst_op->base, inst->extra.size);
+ } else {
+ dst = shift_irdisp8(dst, 31, dst_op->base, dst_op->disp, inst->extra.size);
+ dst = shift_irdisp8(dst, 1, dst_op->base, dst_op->disp, inst->extra.size);
+ }
+
}
- } else {
+ end_off = dst+1;
+ dst = jmp(dst, dst+2);
+ *norm_shift_off = dst - (norm_shift_off+1);
if (dst_op->mode == MODE_REG_DIRECT) {
- dst = shift_ir(dst, 31, dst_op->base, inst->extra.size);
- dst = shift_ir(dst, 1, dst_op->base, inst->extra.size);
+ dst = shift_clr(dst, dst_op->base, inst->extra.size);
} else {
- dst = shift_irdisp8(dst, 31, dst_op->base, dst_op->disp, inst->extra.size);
- dst = shift_irdisp8(dst, 1, dst_op->base, dst_op->disp, inst->extra.size);
+ dst = shift_clrdisp8(dst, dst_op->base, dst_op->disp, inst->extra.size);
}
-
- }
- end_off = dst+1;
- dst = jmp(dst, dst+2);
- *norm_shift_off = dst - (norm_shift_off+1);
- if (dst_op->mode == MODE_REG_DIRECT) {
- dst = shift_clr(dst, dst_op->base, inst->extra.size);
- } else {
- dst = shift_clrdisp8(dst, dst_op->base, dst_op->disp, inst->extra.size);
}
-
}
}
@@ -2702,9 +2752,14 @@ uint8_t * translate_shift(uint8_t * dst, m68kinst * inst, x86_ea *src_op, x86_ea
if (special && end_off) {
*end_off = dst - (end_off + 1);
}
- dst = mov_ir(dst, 0, FLAG_V, SZ_B);
//set X flag to same as C flag
dst = mov_rrind(dst, FLAG_C, CONTEXT, SZ_B);
+ if (z_off) {
+ *z_off = dst - (z_off + 1);
+ }
+ if (inst->op != M68K_ASL && inst->src.addr_mode != MODE_UNUSED && !(src_op->mode == MODE_IMMED && src_op->disp == 1)) {
+ dst = mov_ir(dst, 0, FLAG_V, SZ_B);
+ }
if (inst->src.addr_mode == MODE_UNUSED) {
dst = m68k_save_result(inst, dst, opts);
}
diff --git a/runtime.S b/runtime.S
index 8c126fa..fc308fc 100644
--- a/runtime.S
+++ b/runtime.S
@@ -598,8 +598,8 @@ m68k_retrans_stub:
.global m68k_save_context
m68k_save_context:
mov %bl, 1(%rsi) /* N Flag */
- mov %bh, 2(%rsi) /* V flag */
- mov %dl, 3(%rsi) /* Z flag */
+ mov %dl, 2(%rsi) /* Z flag */
+ mov %bh, 3(%rsi) /* V flag */
mov %dh, 4(%rsi) /* C flag */
mov %r10d, 8(%rsi) /* d0 */
mov %r11d, 12(%rsi) /* d1 */
@@ -613,8 +613,8 @@ m68k_save_context:
.global m68k_load_context
m68k_load_context:
mov 1(%rsi), %bl /* N Flag */
- mov 2(%rsi), %bh /* V flag */
- mov 3(%rsi), %dl /* Z flag */
+ mov 2(%rsi), %dl /* Z flag */
+ mov 3(%rsi), %bh /* V flag */
mov 4(%rsi), %dh /* C flag */
mov 8(%rsi), %r10d /* d0 */
mov 12(%rsi), %r11d /* d1 */
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-19 13:08:46 +0000