[InstCombine] Add trunc(lshr(sext(x),c)) non-uniform vector tests

Author: RKSimon

llvm/test/Transforms/InstCombine/cast.ll

@@ -1546,6 +1546,56 @@ define i8 @trunc_lshr_sext(i8 %A) {
   ret i8 %D
 }
 
+define <2 x i8> @trunc_lshr_sext_uniform(<2 x i8> %A) {
+; ALL-LABEL: @trunc_lshr_sext_uniform(
+; ALL-NEXT:    [[D:%.*]] = ashr <2 x i8> [[A:%.*]], <i8 6, i8 6>
+; ALL-NEXT:    ret <2 x i8> [[D]]
+;
+  %B = sext <2 x i8> %A to <2 x i32>
+  %C = lshr <2 x i32> %B, <i32 6, i32 6>
+  %D = trunc <2 x i32> %C to <2 x i8>
+  ret <2 x i8> %D
+}
+
+define <2 x i8> @trunc_lshr_sext_uniform_undef(<2 x i8> %A) {
+; ALL-LABEL: @trunc_lshr_sext_uniform_undef(
+; ALL-NEXT:    [[B:%.*]] = sext <2 x i8> [[A:%.*]] to <2 x i32>
+; ALL-NEXT:    [[C:%.*]] = lshr <2 x i32> [[B]], <i32 6, i32 undef>
+; ALL-NEXT:    [[D:%.*]] = trunc <2 x i32> [[C]] to <2 x i8>
+; ALL-NEXT:    ret <2 x i8> [[D]]
+;
+  %B = sext <2 x i8> %A to <2 x i32>
+  %C = lshr <2 x i32> %B, <i32 6, i32 undef>
+  %D = trunc <2 x i32> %C to <2 x i8>
+  ret <2 x i8> %D
+}
+
+define <2 x i8> @trunc_lshr_sext_nonuniform(<2 x i8> %A) {
+; ALL-LABEL: @trunc_lshr_sext_nonuniform(
+; ALL-NEXT:    [[B:%.*]] = sext <2 x i8> [[A:%.*]] to <2 x i32>
+; ALL-NEXT:    [[C:%.*]] = lshr <2 x i32> [[B]], <i32 6, i32 2>
+; ALL-NEXT:    [[D:%.*]] = trunc <2 x i32> [[C]] to <2 x i8>
+; ALL-NEXT:    ret <2 x i8> [[D]]
+;
+  %B = sext <2 x i8> %A to <2 x i32>
+  %C = lshr <2 x i32> %B, <i32 6, i32 2>
+  %D = trunc <2 x i32> %C to <2 x i8>
+  ret <2 x i8> %D
+}
+
+define <3 x i8> @trunc_lshr_sext_nonuniform_undef(<3 x i8> %A) {
+; ALL-LABEL: @trunc_lshr_sext_nonuniform_undef(
+; ALL-NEXT:    [[B:%.*]] = sext <3 x i8> [[A:%.*]] to <3 x i32>
+; ALL-NEXT:    [[C:%.*]] = lshr <3 x i32> [[B]], <i32 6, i32 2, i32 undef>
+; ALL-NEXT:    [[D:%.*]] = trunc <3 x i32> [[C]] to <3 x i8>
+; ALL-NEXT:    ret <3 x i8> [[D]]
+;
+  %B = sext <3 x i8> %A to <3 x i32>
+  %C = lshr <3 x i32> %B, <i32 6, i32 2, i32 undef>
+  %D = trunc <3 x i32> %C to <3 x i8>
+  ret <3 x i8> %D
+}
+
 define <2 x i8> @trunc_lshr_sext_uses1(<2 x i8> %A) {
 ; ALL-LABEL: @trunc_lshr_sext_uses1(
 ; ALL-NEXT:    [[B:%.*]] = sext <2 x i8> [[A:%.*]] to <2 x i32>