Mercurial > repos > blastem
changeset 1276:2d8b9d40f5ea
Fix undefined flags on overflow and divide by zero for divu based on hardware test. Fix saving result of divu when destination is not stored in a host register
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Thu, 09 Mar 2017 23:50:46 -0800 |
| parents | f36ef4847ef2 |
| children | 78416556ae02 |
| files | m68k_core_x86.c |
| diffstat | 1 files changed, 5 insertions(+), 6 deletions(-) [+] |
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--- a/m68k_core_x86.c Thu Mar 09 22:17:46 2017 -0800 +++ b/m68k_core_x86.c Thu Mar 09 23:50:46 2017 -0800 @@ -1759,6 +1759,8 @@ isize = 6; break; } + //zero seems to clear all flags + update_flags(opts, N0|Z0|V0); mov_ir(code, VECTOR_INT_DIV_ZERO, opts->gen.scratch2, SZ_D); mov_ir(code, inst->address+isize, opts->gen.scratch1, SZ_D); jmp(code, opts->trap); @@ -1768,11 +1770,8 @@ code_ptr not_overflow = code->cur+1; jcc(code, CC_C, not_overflow); - //flags N and Z flags are set based on internal subtraction of src from top 16-bits of dst - and_ir(code, 0xFFFF0000, opts->gen.scratch2, SZ_D); - cmp_rr(code, opts->gen.scratch1, opts->gen.scratch2, SZ_D); - //TODO: verify N and Z flags are set like I think they are, microcode was a bit confusing - update_flags(opts, N|Z|V1); + //overflow seems to always set the N and clear Z + update_flags(opts, N1|Z0|V1); cycles(&opts->gen, 10); code_ptr end = code->cur+1; jmp(code, end); @@ -1793,7 +1792,7 @@ if (dst_op->mode == MODE_REG_DIRECT) { mov_rr(code, opts->gen.scratch1, dst_op->base, SZ_D); } else { - mov_rrdisp(code, RAX, dst_op->base, dst_op->disp, SZ_D); + mov_rrdisp(code, opts->gen.scratch1, dst_op->base, dst_op->disp, SZ_D); } *end = code->cur - (end + 1);