1 files changed, 17 insertions, 0 deletions
diff --git a/test/CodeGen/AArch64/arm64-coalesce-ext.ll b/test/CodeGen/AArch64/arm64-coalesce-ext.ll
new file mode 100644
index 0000000000..9420bf3bb5
--- /dev/null
+++ b/test/CodeGen/AArch64/arm64-coalesce-ext.ll
@@ -0,0 +1,17 @@
+; RUN: llc -march=arm64 -mtriple=arm64-apple-darwin < %s | FileCheck %s
+; Check that the peephole optimizer knows about sext and zext instructions.
+; CHECK: test1sext
+define i32 @test1sext(i64 %A, i64 %B, i32* %P, i64 *%P2) nounwind {
+  %C = add i64 %A, %B
+  ; CHECK: add x[[SUM:[0-9]+]], x0, x1
+  %D = trunc i64 %C to i32
+  %E = shl i64 %C, 32
+  %F = ashr i64 %E, 32
+  ; CHECK: sxtw x[[EXT:[0-9]+]], w[[SUM]]
+  store volatile i64 %F, i64 *%P2
+  ; CHECK: str x[[EXT]]
+  store volatile i32 %D, i32* %P
+  ; Reuse low bits of extended register, don't extend live range of SUM.
+  ; CHECK: str w[[SUM]]
+  ret i32 %D
+}