Add several testcases for new optimizations in the code generator.

[oota-llvm.git] / test / CodeGen / X86 / overlap-shift.ll

diff --git a/test/CodeGen/X86/overlap-shift.ll b/test/CodeGen/X86/overlap-shift.ll
new file mode 100644 (file)
index 0000000..cf5e897
--- /dev/null
+++ b/test/CodeGen/X86/overlap-shift.ll
@@ -0,0 +1,17 @@
+;; X's live range extends beyond the shift, so the register allocator
+;; cannot coallesce 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: llvm-as < %s | llc -march=x86 -x86-asm-syntax=intel | not grep 'mov %E.X, %E.X'
+
+%G = external global int
+
+int %test1(int %X) {
+       %Z = shl int %X, ubyte 2
+       volatile store int %Z, int* %G
+       ret int %X
+}