Vendor import of llvm trunk r154661:

http://llvm.org/svn/llvm-project/llvm/trunk@r154661

1 files changed, 16 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2011-12-26-extractelement-duplicate-load.ll b/test/CodeGen/X86/2011-12-26-extractelement-duplicate-load.ll
new file mode 100644
index 0000000..39c213f
--- /dev/null
+++ b/test/CodeGen/X86/2011-12-26-extractelement-duplicate-load.ll
@@ -0,0 +1,16 @@
+; RUN: llc -march=x86-64 -mattr=-sse42,+sse41 < %s | FileCheck %s
+; Make sure we don't load from the location pointed to by %p
+; twice: it has non-obvious performance implications, and
+; the relevant transformation doesn't know how to update
+; the chains correctly.
+; PR10747
+
+; CHECK: test:
+; CHECK: pextrd $2, %xmm
+define <4 x i32> @test(<4 x i32>* %p) {
+  %v = load <4 x i32>* %p
+  %e = extractelement <4 x i32> %v, i32 2
+  %cmp = icmp eq i32 %e, 3
+  %sel = select i1 %cmp, <4 x i32> %v, <4 x i32> zeroinitializer
+  ret <4 x i32> %sel
+}