Atomics: switch direction of cmpxchg comparison

This has two benefits: it makes the result more suitable for direct
insertaion into the struct to emulate the new cmpxchg, and it means
the name we give the instruction matches its actual effect better.

llvm-svn: 210916

3 files changed, 18 insertions, 18 deletions

diff --git a/llvm/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp b/llvm/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp
index 6f93ced85b0..6d66e56d426 100644
--- a/llvm/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp
+++ b/llvm/lib/CodeGen/AtomicExpandLoadLinkedPass.cpp
@@ -283,9 +283,9 @@ bool AtomicExpandLoadLinked::expandAtomicCmpXchg(AtomicCmpXchgInst *CI) {
   Builder.SetInsertPoint(TryStoreBB);
   Value *StoreSuccess = TLI->emitStoreConditional(
       Builder, CI->getNewValOperand(), Addr, MemOpOrder);
-  Value *TryAgain = Builder.CreateICmpNE(
+  StoreSuccess = Builder.CreateICmpEQ(
       StoreSuccess, ConstantInt::get(Type::getInt32Ty(Ctx), 0), "success");
-  Builder.CreateCondBr(TryAgain, LoopBB, BarrierBB);
+  Builder.CreateCondBr(StoreSuccess, BarrierBB, LoopBB);
 
   // Make sure later instructions don't get reordered with a fence if necessary.
   Builder.SetInsertPoint(BarrierBB);
diff --git a/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v7.ll b/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v7.ll
index c307d544b60..3a549cdcf29 100644
--- a/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v7.ll
+++ b/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v7.ll
@@ -234,8 +234,8 @@ define i8 @test_cmpxchg_i8_seqcst_seqcst(i8* %ptr, i8 %desired, i8 %newval) {
 ; CHECK: [[TRY_STORE]]:
 ; CHECK: [[NEWVAL32:%.*]] = zext i8 %newval to i32
 ; CHECK: [[TRYAGAIN:%.*]] =  call i32 @llvm.arm.strex.p0i8(i32 [[NEWVAL32]], i8* %ptr)
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK: [[SUCCESS:%.*]] = phi i1 [ true, %[[TRY_STORE]] ], [ false, %[[LOOP]] ]
@@ -264,8 +264,8 @@ define i16 @test_cmpxchg_i16_seqcst_monotonic(i16* %ptr, i16 %desired, i16 %newv
 ; CHECK: [[TRY_STORE]]:
 ; CHECK: [[NEWVAL32:%.*]] = zext i16 %newval to i32
 ; CHECK: [[TRYAGAIN:%.*]] =  call i32 @llvm.arm.strex.p0i16(i32 [[NEWVAL32]], i16* %ptr)
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK: fence seq_cst
@@ -292,8 +292,8 @@ define i32 @test_cmpxchg_i32_acquire_acquire(i32* %ptr, i32 %desired, i32 %newva
 
 ; CHECK: [[TRY_STORE]]:
 ; CHECK: [[TRYAGAIN:%.*]] =  call i32 @llvm.arm.strex.p0i32(i32 %newval, i32* %ptr)
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK: [[SUCCESS:%.*]] = phi i1 [ true, %[[TRY_STORE]] ], [ false, %[[LOOP]] ]
@@ -331,8 +331,8 @@ define i64 @test_cmpxchg_i64_monotonic_monotonic(i64* %ptr, i64 %desired, i64 %n
 ; CHECK: [[NEWHI:%.*]] = trunc i64 [[NEWHI_TMP]] to i32
 ; CHECK: [[PTR8:%.*]] = bitcast i64* %ptr to i8*
 ; CHECK: [[TRYAGAIN:%.*]] = call i32 @llvm.arm.strexd(i32 [[NEWLO]], i32 [[NEWHI]], i8* [[PTR8]])
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK-NOT: fence
diff --git a/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v8.ll b/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v8.ll
index cf641b9f70a..d6781e12642 100644
--- a/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v8.ll
+++ b/llvm/test/Transforms/AtomicExpandLoadLinked/ARM/atomic-expansion-v8.ll
@@ -96,8 +96,8 @@ define i8 @test_cmpxchg_i8_seqcst_seqcst(i8* %ptr, i8 %desired, i8 %newval) {
 ; CHECK: [[TRY_STORE]]:
 ; CHECK: [[NEWVAL32:%.*]] = zext i8 %newval to i32
 ; CHECK: [[TRYAGAIN:%.*]] =  call i32 @llvm.arm.stlex.p0i8(i32 [[NEWVAL32]], i8* %ptr)
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK: [[SUCCESS:%.*]] = phi i1 [ true, %[[TRY_STORE]] ], [ false, %[[LOOP]] ]
@@ -126,8 +126,8 @@ define i16 @test_cmpxchg_i16_seqcst_monotonic(i16* %ptr, i16 %desired, i16 %newv
 ; CHECK: [[TRY_STORE]]:
 ; CHECK: [[NEWVAL32:%.*]] = zext i16 %newval to i32
 ; CHECK: [[TRYAGAIN:%.*]] =  call i32 @llvm.arm.stlex.p0i16(i32 [[NEWVAL32]], i16* %ptr)
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK-NOT: fence
@@ -154,8 +154,8 @@ define i32 @test_cmpxchg_i32_acquire_acquire(i32* %ptr, i32 %desired, i32 %newva
 
 ; CHECK: [[TRY_STORE]]:
 ; CHECK: [[TRYAGAIN:%.*]] =  call i32 @llvm.arm.strex.p0i32(i32 %newval, i32* %ptr)
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK: [[SUCCESS:%.*]] = phi i1 [ true, %[[TRY_STORE]] ], [ false, %[[LOOP]] ]
@@ -193,8 +193,8 @@ define i64 @test_cmpxchg_i64_monotonic_monotonic(i64* %ptr, i64 %desired, i64 %n
 ; CHECK: [[NEWHI:%.*]] = trunc i64 [[NEWHI_TMP]] to i32
 ; CHECK: [[PTR8:%.*]] = bitcast i64* %ptr to i8*
 ; CHECK: [[TRYAGAIN:%.*]] = call i32 @llvm.arm.strexd(i32 [[NEWLO]], i32 [[NEWHI]], i8* [[PTR8]])
-; CHECK: [[TST:%.*]] = icmp ne i32 [[TRYAGAIN]], 0
-; CHECK: br i1 [[TST]], label %[[LOOP]], label %[[BARRIER:.*]]
+; CHECK: [[TST:%.*]] = icmp eq i32 [[TRYAGAIN]], 0
+; CHECK: br i1 [[TST]], label %[[BARRIER:.*]], label %[[LOOP]]
 
 ; CHECK: [[BARRIER]]:
 ; CHECK-NOT: fence