[Qemu-devel] [PATCH 03/11] target-arm: Handle always condition codes within arm_test_cc

[Richard Henderson <rth@twiddle.net>]

Handling this with TCG_COND_ALWAYS will allow these unlikely
cases to be handled without special cases in the rest of the
translator.  The TCG optimizer ought to be able to reduce
these ALWAYS conditions completely.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-arm/translate-a64.c | 9 +++++++++
 target-arm/translate.c     | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 763bf35..219e257 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -1056,6 +1056,14 @@ static void arm_test_cc(DisasCompare *cmp, int cc)
         tcg_gen_andc_i64(value, cpu_ZF, value);
         break;
 
+    case 14: /* always */
+    case 15: /* always */
+        /* Use the ALWAYS condition, which will fold early.
+           It doesn't matter what we use for the value.  */
+        cond = TCG_COND_ALWAYS;
+        value = cpu_ZF;
+        goto no_invert;
+
     default:
         fprintf(stderr, "Bad condition code 0x%x\n", cc);
         abort();
@@ -1065,6 +1073,7 @@ static void arm_test_cc(DisasCompare *cmp, int cc)
         cond = tcg_invert_cond(cond);
     }
 
+ no_invert:
     cmp->cond = cond;
     cmp->value = value;
     cmp->value_global = global;
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 0d0a4d1..54edc33 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -816,6 +816,14 @@ static void arm_test_cc(DisasCompare *cmp, int cc)
         tcg_gen_andc_i32(value, cpu_ZF, value);
         break;
 
+    case 14: /* always */
+    case 15: /* always */
+        /* Use the ALWAYS condition, which will fold early.
+           It doesn't matter what we use for the value.  */
+        cond = TCG_COND_ALWAYS;
+        value = cpu_ZF;
+        goto no_invert;
+
     default:
         fprintf(stderr, "Bad condition code 0x%x\n", cc);
         abort();
@@ -825,6 +833,7 @@ static void arm_test_cc(DisasCompare *cmp, int cc)
         cond = tcg_invert_cond(cond);
     }
 
+ no_invert:
     cmp->cond = cond;
     cmp->value = value;
     cmp->value_global = global;
-- 
2.1.0