target/i386: Create gen_jmp_rel

Create a common helper for pc-relative branches.  The jmp jb insn
was missing a mask for CODE32.  In all cases the CODE64 check was
incorrectly placed, allowing PREFIX_DATA to truncate %rip to 16 bits.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-18-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 29 insertions, 29 deletions

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 11aaba8a65..ba1bd7c707 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -226,6 +226,7 @@ static void gen_eob(DisasContext *s);
 static void gen_jr(DisasContext *s);
 static void gen_jmp(DisasContext *s, target_ulong eip);
 static void gen_jmp_tb(DisasContext *s, target_ulong eip, int tb_num);
+static void gen_jmp_rel(DisasContext *s, MemOp ot, int diff, int tb_num);
 static void gen_op(DisasContext *s1, int op, MemOp ot, int d);
 static void gen_exception_gpf(DisasContext *s);
 
@@ -2792,6 +2793,21 @@ static void gen_jmp_tb(DisasContext *s, target_ulong eip, int tb_num)
     }
 }
 
+static void gen_jmp_rel(DisasContext *s, MemOp ot, int diff, int tb_num)
+{
+    target_ulong dest = s->pc - s->cs_base + diff;
+
+    /* In 64-bit mode, operand size is fixed at 64 bits. */
+    if (!CODE64(s)) {
+        if (ot == MO_16) {
+            dest &= 0xffff;
+        } else {
+            dest &= 0xffffffff;
+        }
+    }
+    gen_jmp_tb(s, dest, tb_num);
+}
+
 static void gen_jmp(DisasContext *s, target_ulong eip)
 {
     gen_jmp_tb(s, eip, 0);
@@ -6862,20 +6878,12 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         break;
     case 0xe8: /* call im */
         {
-            if (dflag != MO_16) {
-                tval = (int32_t)insn_get(env, s, MO_32);
-            } else {
-                tval = (int16_t)insn_get(env, s, MO_16);
-            }
-            tval += s->pc - s->cs_base;
-            if (dflag == MO_16) {
-                tval &= 0xffff;
-            } else if (!CODE64(s)) {
-                tval &= 0xffffffff;
-            }
+            int diff = (dflag != MO_16
+                        ? (int32_t)insn_get(env, s, MO_32)
+                        : (int16_t)insn_get(env, s, MO_16));
             gen_push_v(s, eip_next_tl(s));
             gen_bnd_jmp(s);
-            gen_jmp(s, tval);
+            gen_jmp_rel(s, dflag, diff, 0);
         }
         break;
     case 0x9a: /* lcall im */
@@ -6893,19 +6901,13 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         }
         goto do_lcall;
     case 0xe9: /* jmp im */
-        if (dflag != MO_16) {
-            tval = (int32_t)insn_get(env, s, MO_32);
-        } else {
-            tval = (int16_t)insn_get(env, s, MO_16);
-        }
-        tval += s->pc - s->cs_base;
-        if (dflag == MO_16) {
-            tval &= 0xffff;
-        } else if (!CODE64(s)) {
-            tval &= 0xffffffff;
+        {
+            int diff = (dflag != MO_16
+                        ? (int32_t)insn_get(env, s, MO_32)
+                        : (int16_t)insn_get(env, s, MO_16));
+            gen_bnd_jmp(s);
+            gen_jmp_rel(s, dflag, diff, 0);
         }
-        gen_bnd_jmp(s);
-        gen_jmp(s, tval);
         break;
     case 0xea: /* ljmp im */
         {
@@ -6922,12 +6924,10 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
         }
         goto do_ljmp;
     case 0xeb: /* jmp Jb */
-        tval = (int8_t)insn_get(env, s, MO_8);
-        tval += s->pc - s->cs_base;
-        if (dflag == MO_16) {
-            tval &= 0xffff;
+        {
+            int diff = (int8_t)insn_get(env, s, MO_8);
+            gen_jmp_rel(s, dflag, diff, 0);
         }
-        gen_jmp(s, tval);
         break;
     case 0x70 ... 0x7f: /* jcc Jb */
         tval = (int8_t)insn_get(env, s, MO_8);