1 files changed, 19 insertions, 0 deletions
diff --git a/test/CodeGen/X86/overlap-shift.ll b/test/CodeGen/X86/overlap-shift.ll
new file mode 100644
index 0000000..c1fc041
--- /dev/null
+++ b/test/CodeGen/X86/overlap-shift.ll
@@ -0,0 +1,19 @@
+;; X's live range extends beyond the shift, so the register allocator
+;; cannot coalesce it with Y.  Because of this, a copy needs to be
+;; emitted before the shift to save the register value before it is
+;; clobbered.  However, this copy is not needed if the register
+;; allocator turns the shift into an LEA.  This also occurs for ADD.
+
+; Check that the shift gets turned into an LEA.
+
+; RUN: llc < %s -march=x86 -x86-asm-syntax=intel | \
+; RUN:   not grep {mov E.X, E.X}
+
+@G = external global i32                ; <i32*> [#uses=1]
+
+define i32 @test1(i32 %X) {
+        %Z = shl i32 %X, 2              ; <i32> [#uses=1]
+        volatile store i32 %Z, i32* @G
+        ret i32 %X
+}
+