Merge remote-tracking branch 'remotes/rth/tags/pull-tgt-i386-20140512' into staging

Fix BT zero flag for new Intel manuals

# gpg: Signature made Mon 12 May 2014 22:26:01 BST using RSA key ID 4DD0279B
# gpg: Can't check signature: public key not found

* remotes/rth/tags/pull-tgt-i386-20140512:
  target-i386: Preserve the Z bit for bt/bts/btr/btc
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target-i386/translate.c

@@ -6708,41 +6708,63 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
         }
     bt_op:
         tcg_gen_andi_tl(cpu_T[1], cpu_T[1], (1 << (3 + ot)) - 1);
+        tcg_gen_shr_tl(cpu_tmp4, cpu_T[0], cpu_T[1]);
         switch(op) {
         case 0:
-            tcg_gen_shr_tl(cpu_cc_src, cpu_T[0], cpu_T[1]);
-            tcg_gen_movi_tl(cpu_cc_dst, 0);
             break;
         case 1:
-            tcg_gen_shr_tl(cpu_tmp4, cpu_T[0], cpu_T[1]);
             tcg_gen_movi_tl(cpu_tmp0, 1);
             tcg_gen_shl_tl(cpu_tmp0, cpu_tmp0, cpu_T[1]);
             tcg_gen_or_tl(cpu_T[0], cpu_T[0], cpu_tmp0);
             break;
         case 2:
-            tcg_gen_shr_tl(cpu_tmp4, cpu_T[0], cpu_T[1]);
             tcg_gen_movi_tl(cpu_tmp0, 1);
             tcg_gen_shl_tl(cpu_tmp0, cpu_tmp0, cpu_T[1]);
-            tcg_gen_not_tl(cpu_tmp0, cpu_tmp0);
-            tcg_gen_and_tl(cpu_T[0], cpu_T[0], cpu_tmp0);
+            tcg_gen_andc_tl(cpu_T[0], cpu_T[0], cpu_tmp0);
             break;
         default:
         case 3:
-            tcg_gen_shr_tl(cpu_tmp4, cpu_T[0], cpu_T[1]);
             tcg_gen_movi_tl(cpu_tmp0, 1);
             tcg_gen_shl_tl(cpu_tmp0, cpu_tmp0, cpu_T[1]);
             tcg_gen_xor_tl(cpu_T[0], cpu_T[0], cpu_tmp0);
             break;
         }
-        set_cc_op(s, CC_OP_SARB + ot);
         if (op != 0) {
             if (mod != 3) {
                 gen_op_st_v(s, ot, cpu_T[0], cpu_A0);
             } else {
                 gen_op_mov_reg_v(ot, rm, cpu_T[0]);
             }
+        }
+
+        /* Delay all CC updates until after the store above.  Note that
+           C is the result of the test, Z is unchanged, and the others
+           are all undefined.  */
+        switch (s->cc_op) {
+        case CC_OP_MULB ... CC_OP_MULQ:
+        case CC_OP_ADDB ... CC_OP_ADDQ:
+        case CC_OP_ADCB ... CC_OP_ADCQ:
+        case CC_OP_SUBB ... CC_OP_SUBQ:
+        case CC_OP_SBBB ... CC_OP_SBBQ:
+        case CC_OP_LOGICB ... CC_OP_LOGICQ:
+        case CC_OP_INCB ... CC_OP_INCQ:
+        case CC_OP_DECB ... CC_OP_DECQ:
+        case CC_OP_SHLB ... CC_OP_SHLQ:
+        case CC_OP_SARB ... CC_OP_SARQ:
+        case CC_OP_BMILGB ... CC_OP_BMILGQ:
+            /* Z was going to be computed from the non-zero status of CC_DST.
+               We can get that same Z value (and the new C value) by leaving
+               CC_DST alone, setting CC_SRC, and using a CC_OP_SAR of the
+               same width.  */
             tcg_gen_mov_tl(cpu_cc_src, cpu_tmp4);
-            tcg_gen_movi_tl(cpu_cc_dst, 0);
+            set_cc_op(s, ((s->cc_op - CC_OP_MULB) & 3) + CC_OP_SARB);
+            break;
+        default:
+            /* Otherwise, generate EFLAGS and replace the C bit.  */
+            gen_compute_eflags(s);
+            tcg_gen_deposit_tl(cpu_cc_src, cpu_cc_src, cpu_tmp4,
+                               ctz32(CC_C), 1);
+            break;
         }
         break;
     case 0x1bc: /* bsf / tzcnt */