[InstCombine] Add tests for nsw propagation in negator (NFC)

Author: nikic

llvm/test/Transforms/InstCombine/nsw.ll

@@ -252,3 +252,125 @@ define i32 @sub_sub1_nsw_nsw(i32 %a, i32 %b, i32 %c) {
   %s2 = sub nsw i32 %c, %s1
   ret i32 %s2
 }
+
+define i8 @neg_nsw_select(i1 %c, i8 %a1, i8 %a2, i8 %b1, i8 %b2) {
+; CHECK-LABEL: @neg_nsw_select(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[B_NEG:%.*]] = sub i8 [[B2:%.*]], [[B1:%.*]]
+; CHECK-NEXT:    [[SEL_NEG:%.*]] = select i1 [[C:%.*]], i8 [[A_NEG]], i8 [[B_NEG]]
+; CHECK-NEXT:    ret i8 [[SEL_NEG]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %b = sub nsw i8 %b1, %b2
+  %sel = select i1 %c, i8 %a, i8 %b
+  %neg = sub nsw i8 0, %sel
+  ret i8 %neg
+}
+
+define <4 x i8> @neg_nsw_shufflevector(<2 x i8> %a1, <2 x i8> %a2, <2 x i8> %b1, <2 x i8> %b2) {
+; CHECK-LABEL: @neg_nsw_shufflevector(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub <2 x i8> [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[B_NEG:%.*]] = sub <2 x i8> [[B2:%.*]], [[B1:%.*]]
+; CHECK-NEXT:    [[SHUF_NEG:%.*]] = shufflevector <2 x i8> [[A_NEG]], <2 x i8> [[B_NEG]], <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+; CHECK-NEXT:    ret <4 x i8> [[SHUF_NEG]]
+;
+  %a = sub nsw <2 x i8> %a1, %a2
+  %b = sub nsw <2 x i8> %b1, %b2
+  %shuf = shufflevector <2 x i8> %a, <2 x i8> %b, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %neg = sub nsw <4 x i8> zeroinitializer, %shuf
+  ret <4 x i8> %neg
+}
+
+define i8 @neg_nsw_extractelement(<2 x i8> %a1, <2 x i8> %a2) {
+; CHECK-LABEL: @neg_nsw_extractelement(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub <2 x i8> [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[EXTR_NEG:%.*]] = extractelement <2 x i8> [[A_NEG]], i64 0
+; CHECK-NEXT:    ret i8 [[EXTR_NEG]]
+;
+  %a = sub nsw <2 x i8> %a1, %a2
+  %extr = extractelement <2 x i8> %a, i32 0
+  %neg = sub nsw i8 0, %extr
+  ret i8 %neg
+}
+
+define <2 x i8> @neg_nsw_insertelement(<2 x i8> %a1, <2 x i8> %a2, i8 %b1, i8 %b2) {
+; CHECK-LABEL: @neg_nsw_insertelement(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub <2 x i8> [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[B_NEG:%.*]] = sub i8 [[B2:%.*]], [[B1:%.*]]
+; CHECK-NEXT:    [[INSERT_NEG:%.*]] = insertelement <2 x i8> [[A_NEG]], i8 [[B_NEG]], i64 0
+; CHECK-NEXT:    ret <2 x i8> [[INSERT_NEG]]
+;
+  %a = sub nsw <2 x i8> %a1, %a2
+  %b = sub nsw i8 %b1, %b2
+  %insert  = insertelement <2 x i8> %a, i8 %b, i32 0
+  %neg = sub nsw <2 x i8> zeroinitializer, %insert
+  ret <2 x i8> %neg
+}
+
+define i8 @neg_nsw_shl(i8 %a1, i8 %a2, i8 %b) {
+; CHECK-LABEL: @neg_nsw_shl(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[SHL_NEG:%.*]] = shl i8 [[A_NEG]], [[B:%.*]]
+; CHECK-NEXT:    ret i8 [[SHL_NEG]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %shl = shl nsw i8 %a, %b
+  %neg = sub nsw i8 0, %shl
+  ret i8 %neg
+}
+
+define i8 @neg_nsw_shl_missing_nsw_on_shl(i8 %a1, i8 %a2, i8 %b) {
+; CHECK-LABEL: @neg_nsw_shl_missing_nsw_on_shl(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[SHL_NEG:%.*]] = shl i8 [[A_NEG]], [[B:%.*]]
+; CHECK-NEXT:    ret i8 [[SHL_NEG]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %shl = shl i8 %a, %b
+  %neg = sub nsw i8 0, %shl
+  ret i8 %neg
+}
+
+define i8 @neg_nsw_shl_to_mul(i8 %a, i8 %b) {
+; CHECK-LABEL: @neg_nsw_shl_to_mul(
+; CHECK-NEXT:    [[SHL_NEG:%.*]] = mul i8 [[A:%.*]], -2
+; CHECK-NEXT:    ret i8 [[SHL_NEG]]
+;
+  %shl = shl nsw i8 %a, 1
+  %neg = sub nsw i8 0, %shl
+  ret i8 %neg
+}
+
+define i8 @neg_nsw_shl_to_mul_missing_nsw_on_shl(i8 %a, i8 %b) {
+; CHECK-LABEL: @neg_nsw_shl_to_mul_missing_nsw_on_shl(
+; CHECK-NEXT:    [[SHL_NEG:%.*]] = mul i8 [[A:%.*]], -2
+; CHECK-NEXT:    ret i8 [[SHL_NEG]]
+;
+  %shl = shl i8 %a, 1
+  %neg = sub nsw i8 0, %shl
+  ret i8 %neg
+}
+
+define i8 @neg_nsw_mul(i8 %a1, i8 %a2, i8 %b) {
+; CHECK-LABEL: @neg_nsw_mul(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[SHL_NEG:%.*]] = mul i8 [[A_NEG]], [[B:%.*]]
+; CHECK-NEXT:    ret i8 [[SHL_NEG]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %shl = mul nsw i8 %a, %b
+  %neg = sub nsw i8 0, %shl
+  ret i8 %neg
+}
+
+define i8 @neg_nsw_mul_missing_nsw_on_mul(i8 %a1, i8 %a2, i8 %b) {
+; CHECK-LABEL: @neg_nsw_mul_missing_nsw_on_mul(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[SHL_NEG:%.*]] = mul i8 [[A_NEG]], [[B:%.*]]
+; CHECK-NEXT:    ret i8 [[SHL_NEG]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %shl = mul i8 %a, %b
+  %neg = sub nsw i8 0, %shl
+  ret i8 %neg
+}