Rewrite ppc code generated for __sync_{bool|val}_compare_and_swap

so that lwarx and stwcx are always executed the same number of times.
This is important for performance, I'm told.

llvm-svn: 55163

1 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.td b/llvm/lib/Target/PowerPC/PPCInstrInfo.td
index b4b6080a04e..d8a064625d2 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.td
@@ -553,15 +553,18 @@ let usesCustomDAGSchedInserter = 1 in {
       (outs GPRC:$dst), (ins memrr:$ptr, GPRC:$incr),
       "${:comment} ATOMIC_LOAD_ADD_I32 PSEUDO!",
       [(set GPRC:$dst, (PPCatomic_load_add xoaddr:$ptr, GPRC:$incr))]>;
-    def ATOMIC_CMP_SWAP_I32 : Pseudo<
-      (outs GPRC:$dst), (ins memrr:$ptr, GPRC:$old, GPRC:$new),
-      "${:comment} ATOMIC_CMP_SWAP_I32 PSEUDO!",
-      [(set GPRC:$dst, (PPCatomic_cmp_swap xoaddr:$ptr, GPRC:$old, GPRC:$new))]>;
     def ATOMIC_SWAP_I32 : Pseudo<
       (outs GPRC:$dst), (ins memrr:$ptr, GPRC:$new),
       "${:comment} ATOMIC_SWAP_I32 PSEUDO!",
       [(set GPRC:$dst, (PPCatomic_swap xoaddr:$ptr, GPRC:$new))]>;
   }
+  let Uses = [CR0, CR1] in {
+    def ATOMIC_CMP_SWAP_I32 : Pseudo<
+      (outs GPRC:$dst), (ins memrr:$ptr, GPRC:$old, GPRC:$new),
+      "${:comment} ATOMIC_CMP_SWAP_I32 PSEUDO!",
+      [(set GPRC:$dst, 
+                    (PPCatomic_cmp_swap xoaddr:$ptr, GPRC:$old, GPRC:$new))]>;
+  }
 }
 
 // Instructions to support atomic operations