[llvm] r343378 - [InstCombine] add test for vector widening of insertelements; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Sat Sep 29 08:01:45 2018
New Revision: 343378

URL: http://llvm.org/viewvc/llvm-project?rev=343378&view=rev
Log:
[InstCombine] add test for vector widening of insertelements; NFC

The test shows a potential overreach with the fix from D52548.

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=343378&r1=343377&r2=343378&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/vec_shuffle.ll Sat Sep 29 08:01:45 2018
@@ -218,6 +218,21 @@ define <3 x i32> @div_wider(i32 %y, i32
   ret <3 x i32> %ext
 }
 
+; TODO: Increasing length of insertelements (no math ops) is a good canonicalization.
+
+define <3 x i8> @fold_inselts_with_widening_shuffle(i8 %x, i8 %y) {
+; CHECK-LABEL: @fold_inselts_with_widening_shuffle(
+; CHECK-NEXT:    [[INS0:%.*]] = insertelement <2 x i8> undef, i8 [[X:%.*]], i32 0
+; CHECK-NEXT:    [[INS1:%.*]] = insertelement <2 x i8> [[INS0]], i8 [[Y:%.*]], i32 1
+; CHECK-NEXT:    [[WIDEN:%.*]] = shufflevector <2 x i8> [[INS1]], <2 x i8> undef, <3 x i32> <i32 0, i32 1, i32 undef>
+; CHECK-NEXT:    ret <3 x i8> [[WIDEN]]
+;
+  %ins0 = insertelement <2 x i8> undef, i8 %x, i32 0
+  %ins1 = insertelement <2 x i8> %ins0, i8 %y, i32 1
+  %widen = shufflevector <2 x i8> %ins1, <2 x i8> undef, <3 x i32> <i32 0, i32 1, i32 undef>
+  ret <3 x i8> %widen
+}
+
 define <2 x i8> @test13b(i8 %x) {
 ; CHECK-LABEL: @test13b(
 ; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x i8> undef, i8 [[X:%.*]], i32 1