1 files changed, 47 insertions, 1 deletions

diff --git a/llvm/test/Transforms/InstCombine/atomic.ll b/llvm/test/Transforms/InstCombine/atomic.ll
index 5754a5a4ba5..bf576ba4b3a 100644
--- a/llvm/test/Transforms/InstCombine/atomic.ll
+++ b/llvm/test/Transforms/InstCombine/atomic.ll
@@ -5,12 +5,58 @@ target triple = "x86_64-apple-macosx10.7.0"
 
 ; Check transforms involving atomic operations
 
+define i32 @test1(i32* %p) {
+; CHECK-LABEL: define i32 @test1(
+; CHECK: %x = load atomic i32, i32* %p seq_cst, align 4
+; CHECK: shl i32 %x, 1
+  %x = load atomic i32, i32* %p seq_cst, align 4
+  %y = load i32, i32* %p, align 4
+  %z = add i32 %x, %y
+  ret i32 %z
+}
+
 define i32 @test2(i32* %p) {
 ; CHECK-LABEL: define i32 @test2(
+; CHECK: %x = load volatile i32, i32* %p, align 4
+; CHECK: %y = load volatile i32, i32* %p, align 4
+  %x = load volatile i32, i32* %p, align 4
+  %y = load volatile i32, i32* %p, align 4
+  %z = add i32 %x, %y
+  ret i32 %z
+}
+
+; The exact semantics of mixing volatile and non-volatile on the same
+; memory location are a bit unclear, but conservatively, we know we don't
+; want to remove the volatile.
+define i32 @test3(i32* %p) {
+; CHECK-LABEL: define i32 @test3(
+; CHECK: %x = load volatile i32, i32* %p, align 4
+  %x = load volatile i32, i32* %p, align 4
+  %y = load i32, i32* %p, align 4
+  %z = add i32 %x, %y
+  ret i32 %z
+}
+
+; FIXME: Forwarding from a stronger atomic is fine
+define i32 @test4(i32* %p) {
+; CHECK-LABEL: define i32 @test4(
 ; CHECK: %x = load atomic i32, i32* %p seq_cst, align 4
-; CHECK: shl i32 %x, 1
+; CHECK: %y = load atomic i32, i32* %p unordered, align 4
   %x = load atomic i32, i32* %p seq_cst, align 4
+  %y = load atomic i32, i32* %p unordered, align 4
+  %z = add i32 %x, %y
+  ret i32 %z
+}
+
+; Forwarding from a non-atomic is not.  (The earlier load 
+; could in priciple be promoted to atomic and then forwarded, 
+; but we can't just  drop the atomic from the load.)
+define i32 @test5(i32* %p) {
+; CHECK-LABEL: define i32 @test5(
+; CHECK: %x = load atomic i32, i32* %p unordered, align 4
+  %x = load atomic i32, i32* %p unordered, align 4
   %y = load i32, i32* %p, align 4
   %z = add i32 %x, %y
   ret i32 %z
 }
+