[VectorCombine][X86] Add initial shuffle-of-shuffles.ll test cover for #88743

Author: RKSimon

llvm/test/Transforms/VectorCombine/X86/shuffle-of-shuffles.ll

@@ -0,0 +1,51 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes=vector-combine -S -mtriple=x86_64-- -mattr=sse2 | FileCheck %s
+; RUN: opt < %s -passes=vector-combine -S -mtriple=x86_64-- -mattr=avx2 | FileCheck %s
+
+; TODO: fold to identity
+
+define <8 x i32> @concat_extract_subvectors(<8 x i32> %x) {
+; CHECK-LABEL: define <8 x i32> @concat_extract_subvectors(
+; CHECK-SAME: <8 x i32> [[X:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:    [[LO:%.*]] = shufflevector <8 x i32> [[X]], <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    [[HI:%.*]] = shufflevector <8 x i32> [[X]], <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    [[CONCAT:%.*]] = shufflevector <4 x i32> [[LO]], <4 x i32> [[HI]], <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    ret <8 x i32> [[CONCAT]]
+;
+  %lo = shufflevector <8 x i32> %x, <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %hi = shufflevector <8 x i32> %x, <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+  %concat = shufflevector <4 x i32> %lo, <4 x i32> %hi, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+  ret <8 x i32> %concat
+}
+
+; negative test - shuffle contains undef
+
+define <8 x i32> @concat_extract_subvectors_undef(<8 x i32> %x) {
+; CHECK-LABEL: define <8 x i32> @concat_extract_subvectors_undef(
+; CHECK-SAME: <8 x i32> [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[LO:%.*]] = shufflevector <8 x i32> [[X]], <8 x i32> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 8>
+; CHECK-NEXT:    [[HI:%.*]] = shufflevector <8 x i32> [[X]], <8 x i32> undef, <4 x i32> <i32 4, i32 5, i32 6, i32 8>
+; CHECK-NEXT:    [[CONCAT:%.*]] = shufflevector <4 x i32> [[LO]], <4 x i32> [[HI]], <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    ret <8 x i32> [[CONCAT]]
+;
+  %lo = shufflevector <8 x i32> %x, <8 x i32> undef, <4 x i32> <i32 0, i32 1, i32 2, i32 8>
+  %hi = shufflevector <8 x i32> %x, <8 x i32> undef, <4 x i32> <i32 4, i32 5, i32 6, i32 8>
+  %concat = shufflevector <4 x i32> %lo, <4 x i32> %hi, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+  ret <8 x i32> %concat
+}
+
+; negative test - shuffle contains poision
+
+define <8 x i32> @concat_extract_subvectors_poison(<8 x i32> %x) {
+; CHECK-LABEL: define <8 x i32> @concat_extract_subvectors_poison(
+; CHECK-SAME: <8 x i32> [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    [[LO:%.*]] = shufflevector <8 x i32> [[X]], <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 8>
+; CHECK-NEXT:    [[HI:%.*]] = shufflevector <8 x i32> [[X]], <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 8>
+; CHECK-NEXT:    [[CONCAT:%.*]] = shufflevector <4 x i32> [[LO]], <4 x i32> [[HI]], <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    ret <8 x i32> [[CONCAT]]
+;
+  %lo = shufflevector <8 x i32> %x, <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 8>
+  %hi = shufflevector <8 x i32> %x, <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 8>
+  %concat = shufflevector <4 x i32> %lo, <4 x i32> %hi, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+  ret <8 x i32> %concat
+}