1 files changed, 71 insertions, 2 deletions
diff --git a/test/Transforms/InstCombine/trunc.ll b/test/Transforms/InstCombine/trunc.ll
index eaa45bbb286c8..5597b578f0179 100644
--- a/test/Transforms/InstCombine/trunc.ll
+++ b/test/Transforms/InstCombine/trunc.ll
@@ -119,8 +119,8 @@ define i64 @test8(i32 %A, i32 %B) {
 
 define i8 @test9(i32 %X) {
 ; CHECK-LABEL: @test9(
-; CHECK-NEXT:    [[X_TR:%.*]] = trunc i32 %X to i8
-; CHECK-NEXT:    [[Z:%.*]] = and i8 [[X_TR]], 42
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 %X to i8
+; CHECK-NEXT:    [[Z:%.*]] = and i8 [[TMP1]], 42
 ; CHECK-NEXT:    ret i8 [[Z]]
 ;
   %Y = and i32 %X, 42
@@ -464,3 +464,72 @@ define <8 x i16> @trunc_shl_v8i16_v8i32_4(<8 x i32> %a) {
   ret <8 x i16> %conv
 }
 
+; Although the mask is the same value, we don't create a shuffle for types that the backend may not be able to handle:
+; trunc (shuffle X, C, Mask) --> shuffle (trunc X), C', Mask
+
+define <4 x i8> @wide_shuf(<4 x i32> %x) {
+; CHECK-LABEL: @wide_shuf(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> %x, <4 x i32> <i32 undef, i32 3634, i32 90, i32 undef>, <4 x i32> <i32 1, i32 5, i32 6, i32 2>
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc <4 x i32> [[SHUF]] to <4 x i8>
+; CHECK-NEXT:    ret <4 x i8> [[TRUNC]]
+;
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> <i32 35, i32 3634, i32 90, i32 -1>, <4 x i32> <i32 1, i32 5, i32 6, i32 2>
+  %trunc = trunc <4 x i32> %shuf to <4 x i8>
+  ret <4 x i8> %trunc
+}
+
+; trunc (shuffle X, undef, SplatMask) --> shuffle (trunc X), undef, SplatMask
+
+define <4 x i8> @wide_splat1(<4 x i32> %x) {
+; CHECK-LABEL: @wide_splat1(
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc <4 x i32> %x to <4 x i8>
+; CHECK-NEXT:    [[TRUNC:%.*]] = shufflevector <4 x i8> [[TMP1]], <4 x i8> undef, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
+; CHECK-NEXT:    ret <4 x i8> [[TRUNC]]
+;
+  %shuf = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
+  %trunc = trunc <4 x i32> %shuf to <4 x i8>
+  ret <4 x i8> %trunc
+}
+
+; Test weird types.
+; trunc (shuffle X, undef, SplatMask) --> shuffle (trunc X), undef, SplatMask
+
+define <3 x i31> @wide_splat2(<3 x i33> %x) {
+; CHECK-LABEL: @wide_splat2(
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc <3 x i33> %x to <3 x i31>
+; CHECK-NEXT:    [[TRUNC:%.*]] = shufflevector <3 x i31> [[TMP1]], <3 x i31> undef, <3 x i32> <i32 1, i32 1, i32 1>
+; CHECK-NEXT:    ret <3 x i31> [[TRUNC]]
+;
+  %shuf = shufflevector <3 x i33> %x, <3 x i33> undef, <3 x i32> <i32 1, i32 1, i32 1>
+  %trunc = trunc <3 x i33> %shuf to <3 x i31>
+  ret <3 x i31> %trunc
+}
+
+; FIXME:
+; trunc (shuffle X, undef, SplatMask) --> shuffle (trunc X), undef, SplatMask
+; A mask with undef elements should still be considered a splat mask.
+
+define <3 x i31> @wide_splat3(<3 x i33> %x) {
+; CHECK-LABEL: @wide_splat3(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <3 x i33> %x, <3 x i33> undef, <3 x i32> <i32 undef, i32 1, i32 1>
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc <3 x i33> [[SHUF]] to <3 x i31>
+; CHECK-NEXT:    ret <3 x i31> [[TRUNC]]
+;
+  %shuf = shufflevector <3 x i33> %x, <3 x i33> undef, <3 x i32> <i32 undef, i32 1, i32 1>
+  %trunc = trunc <3 x i33> %shuf to <3 x i31>
+  ret <3 x i31> %trunc
+}
+
+; TODO: The shuffle extends the length of the input vector. Should we shrink this?
+
+define <8 x i8> @wide_lengthening_splat(<4 x i16> %v) {
+; CHECK-LABEL: @wide_lengthening_splat(
+; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i16> %v, <4 x i16> undef, <8 x i32> zeroinitializer
+; CHECK-NEXT:    [[TR:%.*]] = trunc <8 x i16> [[SHUF]] to <8 x i8>
+; CHECK-NEXT:    ret <8 x i8> [[TR]]
+;
+  %shuf = shufflevector <4 x i16> %v, <4 x i16> %v, <8 x i32> zeroinitializer
+  %tr = trunc <8 x i16> %shuf to <8 x i8>
+  ret <8 x i8> %tr
+}
+