gwj / at91sam9263 · Commits

Commit 686f3f266b829b06c7b170db7b4ce97abfbfc517

Authored by bellard
1 parent 5b1214a4

BSR/BSF undefined behaviour fix 


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@809 c046a42c-6fe2-441c-8c8c-71466251a162
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Showing 2 changed files with 6 additions and 5 deletions
target-i386/ops_template.h
  View file @686f3f2
... ... @@ -513,7 +513,7 @@ void OPPROTO glue(glue(op_bsf, SUFFIX), _T0_cc)(void)
513 513 count++;
514 514 res >>= 1;
515 515 }
516   - T0 = count;
  516 + T1 = count;
517 517 CC_DST = 1; /* ZF = 0 */
518 518 } else {
519 519 CC_DST = 0; /* ZF = 1 */
... ... @@ -531,7 +531,7 @@ void OPPROTO glue(glue(op_bsr, SUFFIX), _T0_cc)(void)
531 531 count--;
532 532 res <<= 1;
533 533 }
534   - T0 = count;
  534 + T1 = count;
535 535 CC_DST = 1; /* ZF = 0 */
536 536 } else {
537 537 CC_DST = 0; /* ZF = 1 */
... ...
target-i386/translate.c
  View file @686f3f2
... ... @@ -3708,10 +3708,11 @@ static uint8_t *disas_insn(DisasContext *s, uint8_t *pc_start)
3708 3708 modrm = ldub_code(s->pc++);
3709 3709 reg = (modrm >> 3) & 7;
3710 3710 gen_ldst_modrm(s, modrm, ot, OR_TMP0, 0);
  3711 + /* NOTE: in order to handle the 0 case, we must load the
  3712 + result. It could be optimized with a generated jump */
  3713 + gen_op_mov_TN_reg[ot][1][reg]();
3711 3714 gen_op_bsx_T0_cc[ot - OT_WORD][b & 1]();
3712   - /* NOTE: we always write back the result. Intel doc says it is
3713   - undefined if T0 == 0 */
3714   - gen_op_mov_reg_T0[ot][reg]();
  3715 + gen_op_mov_reg_T1[ot][reg]();
3715 3716 s->cc_op = CC_OP_LOGICB + ot;
3716 3717 break;
3717 3718 /************************/
... ...