[InstCombine] Add extra tests for FoldOpIntoSelect (NFC)

Author: nikic

llvm/test/Transforms/InstCombine/select.ll

@@ -4729,3 +4729,44 @@ define i32 @pr99436(ptr align 4 dereferenceable(4) %ptr) {
   %ret = select i1 %cmp, i32 %val, i32 0
   ret i32 %ret
 }
+
+define i8 @sel_trunc_simplify(i1 %c, i8 %x, i16 %y) {
+; CHECK-LABEL: @sel_trunc_simplify(
+; CHECK-NEXT:    [[X_EXT:%.*]] = zext i8 [[X:%.*]] to i16
+; CHECK-NEXT:    [[Y:%.*]] = select i1 [[C:%.*]], i16 [[X_EXT]], i16 [[Y1:%.*]]
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc i16 [[Y]] to i8
+; CHECK-NEXT:    ret i8 [[TMP1]]
+;
+  %x.ext = zext i8 %x to i16
+  %sel = select i1 %c, i16 %x.ext, i16 %y
+  %trunc = trunc i16 %sel to i8
+  ret i8 %trunc
+}
+
+define i32 @sel_umin_simplify(i1 %c, i32 %x, i16 %y) {
+; CHECK-LABEL: @sel_umin_simplify(
+; CHECK-NEXT:    [[X:%.*]] = select i1 [[C:%.*]], i32 [[X1:%.*]], i32 0
+; CHECK-NEXT:    [[ARG2_EXT:%.*]] = zext i16 [[ARG2:%.*]] to i32
+; CHECK-NEXT:    [[TMP1:%.*]] = call i32 @llvm.umin.i32(i32 [[X]], i32 [[ARG2_EXT]])
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %sel = select i1 %c, i32 %x, i32 0
+  %y.ext = zext i16 %y to i32
+  %res = call i32 @llvm.umin.i32(i32 %sel, i32 %y.ext)
+  ret i32 %res
+}
+
+define i32 @sel_extractvalue_simplify(i1 %c, { i32, i32 } %agg1, i32 %x, i32 %y) {
+; CHECK-LABEL: @sel_extractvalue_simplify(
+; CHECK-NEXT:    [[AGG2_0:%.*]] = insertvalue { i32, i32 } poison, i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[AGG2_1:%.*]] = insertvalue { i32, i32 } [[AGG2_0]], i32 [[Y:%.*]], 1
+; CHECK-NEXT:    [[AGG1:%.*]] = select i1 [[C:%.*]], { i32, i32 } [[AGG2:%.*]], { i32, i32 } [[AGG2_1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { i32, i32 } [[AGG1]], 1
+; CHECK-NEXT:    ret i32 [[TMP1]]
+;
+  %agg2.0 = insertvalue { i32, i32 } poison, i32 %x, 0
+  %agg2.1 = insertvalue { i32, i32 } %agg2.0, i32 %y, 1
+  %sel = select i1 %c, { i32, i32 } %agg1, { i32, i32 } %agg2.1
+  %res = extractvalue { i32, i32 } %sel, 1
+  ret i32 %res
+}