diff options
| author | bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162> | 2004-05-16 15:56:04 +0000 |
|---|---|---|
| committer | bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162> | 2004-05-16 15:56:04 +0000 |
| commit | 686f3f266b829b06c7b170db7b4ce97abfbfc517 (patch) | |
| tree | 49fd086fcbd20afb46471e5b8db0027d2fec8b3c /target-i386 | |
| parent | 5b1214a48ed5564e35e367864b744d81a6d4d660 (diff) | |
| download | qemu-686f3f266b829b06c7b170db7b4ce97abfbfc517.tar.gz | |
BSR/BSF undefined behaviour fix
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@809 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'target-i386')
| -rw-r--r-- | target-i386/ops_template.h | 4 | ||||
| -rw-r--r-- | target-i386/translate.c | 7 |
2 files changed, 6 insertions, 5 deletions
diff --git a/target-i386/ops_template.h b/target-i386/ops_template.h index 037c4306a3..2ff1f66648 100644 --- a/target-i386/ops_template.h +++ b/target-i386/ops_template.h @@ -513,7 +513,7 @@ void OPPROTO glue(glue(op_bsf, SUFFIX), _T0_cc)(void) count++; res >>= 1; } - T0 = count; + T1 = count; CC_DST = 1; /* ZF = 0 */ } else { CC_DST = 0; /* ZF = 1 */ @@ -531,7 +531,7 @@ void OPPROTO glue(glue(op_bsr, SUFFIX), _T0_cc)(void) count--; res <<= 1; } - T0 = count; + T1 = count; CC_DST = 1; /* ZF = 0 */ } else { CC_DST = 0; /* ZF = 1 */ diff --git a/target-i386/translate.c b/target-i386/translate.c index c6aa5030ed..514399d937 100644 --- a/target-i386/translate.c +++ b/target-i386/translate.c @@ -3708,10 +3708,11 @@ static uint8_t *disas_insn(DisasContext *s, uint8_t *pc_start) modrm = ldub_code(s->pc++); reg = (modrm >> 3) & 7; gen_ldst_modrm(s, modrm, ot, OR_TMP0, 0); + /* NOTE: in order to handle the 0 case, we must load the + result. It could be optimized with a generated jump */ + gen_op_mov_TN_reg[ot][1][reg](); gen_op_bsx_T0_cc[ot - OT_WORD][b & 1](); - /* NOTE: we always write back the result. Intel doc says it is - undefined if T0 == 0 */ - gen_op_mov_reg_T0[ot][reg](); + gen_op_mov_reg_T1[ot][reg](); s->cc_op = CC_OP_LOGICB + ot; break; /************************/ |