[InstCombine] Test trunc to i1 in foldSelectICmpAnd. (NFC)

Author: andjo403

llvm/test/Transforms/InstCombine/select-icmp-and.ll

@@ -809,3 +809,97 @@ define i8 @select_bittest_to_xor(i8 %x) {
   %masksel = select i1 %cmp, i8 %or, i8 %and
   ret i8 %masksel
 }
+
+define i8 @select_trunc_bittest_to_sub(i8 %x) {
+; CHECK-LABEL: @select_trunc_bittest_to_sub(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i8 [[X:%.*]] to i1
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 3, i8 4
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc i8 %x to i1
+  %ret = select i1 %trunc, i8 3, i8 4
+  ret i8 %ret
+}
+
+define i8 @select_trunc_nuw_bittest_to_sub(i8 %x) {
+; CHECK-LABEL: @select_trunc_nuw_bittest_to_sub(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc nuw i8 [[X:%.*]] to i1
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 3, i8 4
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc nuw i8 %x to i1
+  %ret = select i1 %trunc, i8 3, i8 4
+  ret i8 %ret
+}
+
+define i8 @select_trunc_nsw_bittest_to_sub(i8 %x) {
+; CHECK-LABEL: @select_trunc_nsw_bittest_to_sub(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc nsw i8 [[X:%.*]] to i1
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 3, i8 4
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc nsw i8 %x to i1
+  %ret = select i1 %trunc, i8 3, i8 4
+  ret i8 %ret
+}
+
+define i8 @select_trunc_nuw_bittest_to_sub_extra_use(i8 %x) {
+; CHECK-LABEL: @select_trunc_nuw_bittest_to_sub_extra_use(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc nuw i8 [[X:%.*]] to i1
+; CHECK-NEXT:    call void @use1(i1 [[TRUNC]])
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 3, i8 4
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc nuw i8 %x to i1
+  call void @use1(i1 %trunc)
+  %ret = select i1 %trunc, i8 3, i8 4
+  ret i8 %ret
+}
+
+define i8 @neg_select_trunc_bittest_to_sub_extra_use(i8 %x) {
+; CHECK-LABEL: @neg_select_trunc_bittest_to_sub_extra_use(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i8 [[X:%.*]] to i1
+; CHECK-NEXT:    call void @use1(i1 [[TRUNC]])
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 3, i8 4
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc i8 %x to i1
+  call void @use1(i1 %trunc)
+  %ret = select i1 %trunc, i8 3, i8 4
+  ret i8 %ret
+}
+
+define i8 @select_trunc_nuw_bittest_to_shl_not(i8 %x) {
+; CHECK-LABEL: @select_trunc_nuw_bittest_to_shl_not(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc nuw i8 [[X:%.*]] to i1
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 0, i8 4
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc nuw i8 %x to i1
+  %ret = select i1 %trunc, i8 0, i8 4
+  ret i8 %ret
+}
+
+define i8 @select_trunc_bittest_to_shl(i8 %x) {
+; CHECK-LABEL: @select_trunc_bittest_to_shl(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i8 [[X:%.*]] to i1
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 4, i8 0
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc i8 %x to i1
+  %ret = select i1 %trunc, i8 4, i8 0
+  ret i8 %ret
+}
+
+define i8 @neg_select_trunc_bittest_to_shl_extra_use(i8 %x) {
+; CHECK-LABEL: @neg_select_trunc_bittest_to_shl_extra_use(
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i8 [[X:%.*]] to i1
+; CHECK-NEXT:    call void @use1(i1 [[TRUNC]])
+; CHECK-NEXT:    [[RET:%.*]] = select i1 [[TRUNC]], i8 4, i8 0
+; CHECK-NEXT:    ret i8 [[RET]]
+;
+  %trunc = trunc i8 %x to i1
+  call void @use1(i1 %trunc)
+  %ret = select i1 %trunc, i8 4, i8 0
+  ret i8 %ret
+}