Instsimplify: Adding shufflevector test. NFC.

Adding some test-cases demonstrating cases that need to be improved.
To be followed by patches that improve these cases.

llvm-svn: 299189

diff --git a/llvm/test/Transforms/InstSimplify/shufflevector.ll b/llvm/test/Transforms/InstSimplify/shufflevector.ll
new file mode 100644 (file)
index 0000000..1baecd2
--- /dev/null
+++ b/llvm/test/Transforms/InstSimplify/shufflevector.ll
@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+define <4 x i32> @splat_operand(<4 x i32> %x) {
+; CHECK-LABEL: @splat_operand(
+; CHECK-NEXT:    [[SPLAT:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[SPLAT]], <4 x i32> undef, <4 x i32> <i32 0, i32 3, i32 2, i32 1>
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %splat = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> zeroinitializer
+  %shuf = shufflevector <4 x i32> %splat, <4 x i32> undef, <4 x i32> <i32 0, i32 3, i32 2, i32 1>
+  ret <4 x i32> %shuf
+}
+
+define <4 x i32> @undef_mask(<4 x i32> %x) {
+; CHECK-LABEL: @undef_mask(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> undef
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> undef
+  ret <4 x i32> %shuf
+}
+
+define <4 x i32> @identity_mask_0(<4 x i32> %x) {
+; CHECK-LABEL: @identity_mask_0(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  ret <4 x i32> %shuf
+}
+
+define <4 x i32> @identity_mask_1(<4 x i32> %x) {
+; CHECK-LABEL: @identity_mask_1(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> undef, <4 x i32> [[X:%.*]], <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %shuf = shufflevector <4 x i32> undef, <4 x i32> %x, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+  ret <4 x i32> %shuf
+}
+
+define <4 x i32> @pseudo_identity_mask(<4 x i32> %x) {
+; CHECK-LABEL: @pseudo_identity_mask(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> [[X]], <4 x i32> <i32 0, i32 1, i32 2, i32 7>
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> %x, <4 x i32> <i32 0, i32 1, i32 2, i32 7>
+  ret <4 x i32> %shuf
+}
+
+define <4 x i32> @const_operand(<4 x i32> %x) {
+; CHECK-LABEL: @const_operand(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> <i32 42, i32 43, i32 44, i32 45>, <4 x i32> [[X:%.*]], <4 x i32> <i32 0, i32 3, i32 2, i32 1>
+; CHECK-NEXT:    ret <4 x i32> [[SHUF]]
+;
+  %shuf = shufflevector <4 x i32> <i32 42, i32 43, i32 44, i32 45>, <4 x i32> %x, <4 x i32> <i32 0, i32 3, i32 2, i32 1>
+  ret <4 x i32> %shuf
+}
+
+define <4 x i32> @merge(<4 x i32> %x) {
+; CHECK-LABEL: @merge(
+; CHECK-NEXT:    [[LOWER:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> undef, <2 x i32> <i32 1, i32 0>
+; CHECK-NEXT:    [[UPPER:%.*]] = shufflevector <4 x i32> [[X]], <4 x i32> undef, <2 x i32> <i32 2, i32 3>
+; CHECK-NEXT:    [[MERGED:%.*]] = shufflevector <2 x i32> [[UPPER]], <2 x i32> [[LOWER]], <4 x i32> <i32 3, i32 2, i32 0, i32 1>
+; CHECK-NEXT:    ret <4 x i32> [[MERGED]]
+;
+  %lower = shufflevector <4 x i32> %x, <4 x i32> undef, <2 x i32> <i32 1, i32 0>
+  %upper = shufflevector <4 x i32> %x, <4 x i32> undef, <2 x i32> <i32 2, i32 3>
+  %merged = shufflevector <2 x i32> %upper, <2 x i32> %lower, <4 x i32> <i32 3, i32 2, i32 0, i32 1>
+  ret <4 x i32> %merged
+}