[CodeGen] Combine concat_vector of trunc'd scalar to scalar_to_vector.

[oota-llvm.git] / test / CodeGen / AArch64 / concat_vector-truncated-scalar-combine.ll

diff --git a/test/CodeGen/AArch64/concat_vector-truncated-scalar-combine.ll b/test/CodeGen/AArch64/concat_vector-truncated-scalar-combine.ll
new file mode 100644 (file)
index 0000000..eb6c80d
--- /dev/null
+++ b/test/CodeGen/AArch64/concat_vector-truncated-scalar-combine.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple aarch64-unknown-unknown -asm-verbose=false | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+
+; Test the (concat_vectors (bitcast (trunc (scalar))), undef..) pattern.
+
+define <8 x i8> @test_concat_from_truncated_scalar(i32 %x) #0 {
+entry:
+; CHECK-LABEL: test_concat_from_truncated_scalar:
+; CHECK-NEXT: fmov s0, w0
+; CHECK-NEXT: ret
+  %t = trunc i32 %x to i16
+  %0 = bitcast i16 %t to <2 x i8>
+  %1 = shufflevector <2 x i8> %0, <2 x i8> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2>
+  ret <8 x i8> %1
+}
+
+attributes #0 = { nounwind }