[llvm] r361317 - [InstCombine] add more tests for shuffle folding; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Tue May 21 14:45:24 2019
New Revision: 361317

URL: http://llvm.org/viewvc/llvm-project?rev=361317&view=rev
Log:
[InstCombine] add more tests for shuffle folding; NFC

As discussed in D62024, we want to limit any potential IR
transforms of shuffles to cases where we know the SDAG
conversion would result in equivalent patterns for these
IR variants.

Modified:
    llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll

Modified: llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll?rev=361317&r1=361316&r2=361317&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll Tue May 21 14:45:24 2019
@@ -1153,6 +1153,19 @@ define <7 x i8> @insert_subvector_shuffl
   ret <7 x i8> %s3
 }
 
+define <8 x i8> @insert_subvector_shuffles_pow2elts(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @insert_subvector_shuffles_pow2elts(
+; CHECK-NEXT:    [[S1:%.*]] = shufflevector <2 x i8> [[X:%.*]], <2 x i8> undef, <8 x i32> <i32 0, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[S2:%.*]] = shufflevector <2 x i8> [[Y:%.*]], <2 x i8> undef, <8 x i32> <i32 0, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[S3:%.*]] = shufflevector <8 x i8> [[S1]], <8 x i8> [[S2]], <8 x i32> <i32 0, i32 8, i32 1, i32 undef, i32 8, i32 1, i32 9, i32 0>
+; CHECK-NEXT:    ret <8 x i8> [[S3]]
+;
+  %s1 = shufflevector <2 x i8> %x, <2 x i8> undef, <8 x i32> <i32 0, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  %s2 = shufflevector <2 x i8> %y, <2 x i8> undef, <8 x i32> <i32 0, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  %s3 = shufflevector <8 x i8> %s1, <8 x i8> %s2, <8 x i32> <i32 0, i32 8, i32 1, i32 undef, i32 8, i32 1, i32 9, i32 0>
+  ret <8 x i8> %s3
+}
+
 ; The last shuffle may change the vector type.
 
 define <2 x i8> @insert_subvector_shuffles_narrowing(<3 x i8> %x, <3 x i8> %y) {
@@ -1168,6 +1181,19 @@ define <2 x i8> @insert_subvector_shuffl
   ret <2 x i8> %s3
 }
 
+define <2 x i8> @insert_subvector_shuffles_narrowing_pow2elts(<4 x i8> %x, <4 x i8> %y) {
+; CHECK-LABEL: @insert_subvector_shuffles_narrowing_pow2elts(
+; CHECK-NEXT:    [[S1:%.*]] = shufflevector <4 x i8> [[X:%.*]], <4 x i8> undef, <8 x i32> <i32 0, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[S2:%.*]] = shufflevector <4 x i8> [[Y:%.*]], <4 x i8> undef, <8 x i32> <i32 0, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT:    [[S3:%.*]] = shufflevector <8 x i8> [[S1]], <8 x i8> [[S2]], <2 x i32> <i32 0, i32 8>
+; CHECK-NEXT:    ret <2 x i8> [[S3]]
+;
+  %s1 = shufflevector <4 x i8> %x, <4 x i8> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  %s2 = shufflevector <4 x i8> %y, <4 x i8> undef, <8 x i32> <i32 0, i32 1, i32 undef, i32 3, i32 undef, i32 undef, i32 undef, i32 undef>
+  %s3 = shufflevector <8 x i8> %s1, <8 x i8> %s2, <2 x i32> <i32 0, i32 8>
+  ret <2 x i8> %s3
+}
+
 ; Similar to above, but this reduces to a widen with undefs of 'x'.
 
 define <4 x double> @insert_subvector_shuffles_identity(<2 x double> %x) {