add unit test

Author: daniel-zabawa

llvm/test/CodeGen/X86/pr128052.ll

@@ -0,0 +1,30 @@
+; Ensure assertion is not hit when folding concat of two contiguous extract_subvector operations
+; from a source with a non-power-of-two vector length.
+; RUN: llc -mattr=+avx2 < %s
+
+source_filename = "foo.c"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @foo(ptr noundef %pDst, ptr noundef %pSrc) {
+bb0:
+  %sptr1 = getelementptr i8, ptr %pSrc, i64 32
+  %load598 = load <12 x float>, ptr %sptr1, align 1
+  br label %bb1
+bb1:
+  %sptr0 = getelementptr i8, ptr %pSrc, i64 16
+  %load617 = load <12 x float>, ptr %sptr0, align 1
+  %42 = fsub contract <12 x float> %load617, %load598
+  %43 = shufflevector <12 x float> %42, <12 x float> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %44 = fsub contract <12 x float> %load617, %load598
+  %45 = shufflevector <12 x float> %44, <12 x float> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+  %46 = fsub contract <12 x float> %load617, %load598
+  %47 = shufflevector <12 x float> %46, <12 x float> poison, <4 x i32> <i32 8, i32 9, i32 10, i32 11>
+  %dptr0 = getelementptr i8, ptr %pDst, i64 16
+  %dptr1 = getelementptr i8, ptr %pDst, i64 32 
+  %dptr2 = getelementptr i8, ptr %pDst, i64 48
+  store <4 x float> %43, ptr %dptr0, align 1
+  store <4 x float> %45, ptr %dptr1, align 1
+  store <4 x float> %47, ptr %dptr2, align 1
+  ret void
+}