vendor/llvm/llvm-r72732

1 files changed, 17 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2005-01-17-CycleInDAG.ll b/test/CodeGen/X86/2005-01-17-CycleInDAG.ll
new file mode 100644
index 000000000000..37cff57f30e2
--- /dev/null
+++ b/test/CodeGen/X86/2005-01-17-CycleInDAG.ll
@@ -0,0 +1,17 @@
+; This testcase was distilled from 132.ijpeg.  Bsaically we cannot fold the
+; load into the sub instruction here as it induces a cycle in the dag, which
+; is invalid code (there is no correct way to order the instruction).  Check
+; that we do not fold the load into the sub.
+
+; RUN: llvm-as < %s | llc -march=x86 | not grep sub.*GLOBAL
+
+@GLOBAL = external global i32           ; <i32*> [#uses=1]
+
+define i32 @test(i32* %P1, i32* %P2, i32* %P3) {
+        %L = load i32* @GLOBAL          ; <i32> [#uses=1]
+        store i32 12, i32* %P2
+        %Y = load i32* %P3              ; <i32> [#uses=1]
+        %Z = sub i32 %Y, %L             ; <i32> [#uses=1]
+        ret i32 %Z
+}
+