| Message ID | 1439151229-27747-13-git-send-email-laurent@vivier.eu |
|---|---|
| State | New |
| Headers | show |
On 08/09/2015 01:13 PM, Laurent Vivier wrote: > "Overflow may be detected and set before the instruction completes. > If the instruction detects an overflow, it sets the overflow condition > code, and the operands are unaffected." May also implies may not. I presume this is important for matching hardware? Is there some program you know of that depends on this? > + /* dest.l / src.w */ > + > + dest = DREG(insn, 9); > + tcg_gen_mov_i32(QREG_DIV1, dest); > + > SRC_EA(env, src, OS_WORD, sign, NULL); > tcg_gen_mov_i32(QREG_DIV2, src); > + > + /* div1 / div2 */ > + > if (sign) { > gen_helper_divs(cpu_env, tcg_const_i32(1)); > } else { > gen_helper_divu(cpu_env, tcg_const_i32(1)); > } > > + set_cc_op(s, CC_OP_FLAGS); > + > + l1 = gen_new_label(); > + gen_jmpcc(s, 9 /* V */, l1); > tmp = tcg_temp_new(); > src = tcg_temp_new(); > tcg_gen_ext16u_i32(tmp, QREG_DIV1); > tcg_gen_shli_i32(src, QREG_DIV2, 16); > - tcg_gen_or_i32(reg, tmp, src); > - set_cc_op(s, CC_OP_FLAGS); > + tcg_gen_or_i32(dest, tmp, src); > + gen_set_label(l1); All that said, it's possible to implement this branch inside the helper via exception. Or simply return the inputs to effect no change. r~
diff --git a/target-m68k/translate.c b/target-m68k/translate.c index 8a3d315..370a2f0 100644 --- a/target-m68k/translate.c +++ b/target-m68k/translate.c @@ -1034,32 +1034,40 @@ DISAS_INSN(mulw) DISAS_INSN(divw) { - TCGv reg; + TCGv dest; TCGv tmp; TCGv src; int sign; + TCGLabel *l1; sign = (insn & 0x100) != 0; - reg = DREG(insn, 9); - if (sign) { - tcg_gen_ext16s_i32(QREG_DIV1, reg); - } else { - tcg_gen_ext16u_i32(QREG_DIV1, reg); - } + + /* dest.l / src.w */ + + dest = DREG(insn, 9); + tcg_gen_mov_i32(QREG_DIV1, dest); + SRC_EA(env, src, OS_WORD, sign, NULL); tcg_gen_mov_i32(QREG_DIV2, src); + + /* div1 / div2 */ + if (sign) { gen_helper_divs(cpu_env, tcg_const_i32(1)); } else { gen_helper_divu(cpu_env, tcg_const_i32(1)); } + set_cc_op(s, CC_OP_FLAGS); + + l1 = gen_new_label(); + gen_jmpcc(s, 9 /* V */, l1); tmp = tcg_temp_new(); src = tcg_temp_new(); tcg_gen_ext16u_i32(tmp, QREG_DIV1); tcg_gen_shli_i32(src, QREG_DIV2, 16); - tcg_gen_or_i32(reg, tmp, src); - set_cc_op(s, CC_OP_FLAGS); + tcg_gen_or_i32(dest, tmp, src); + gen_set_label(l1); } DISAS_INSN(divl)
"Overflow may be detected and set before the instruction completes. If the instruction detects an overflow, it sets the overflow condition code, and the operands are unaffected." Signed-off-by: Laurent Vivier <laurent@vivier.eu> --- target-m68k/translate.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)