[InstCombine] Tests for (a+b)<=a && (a+b)!=0 fold (PR43259)

https://rise4fun.com/Alive/knp
https://rise4fun.com/Alive/ALap

llvm-svn: 372402

diff --git a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll
index 1a376c4..1253988 100644 (file)
--- a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll
+++ b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-is-non-zero-and-no-underflow.ll
@@ -1,10 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt %s -instcombine -S | FileCheck %s
 
-; Here we add unsigned two values, check that addition did not underflow AND
-; that the result is non-zero. This can be simplified just to a comparison
-; between the base and negated offset.
-
 declare void @use8(i8)
 
 declare void @use1(i1)
@@ -233,3 +229,26 @@ define i1 @t8(i8 %base, i8 %offset) {
   %r = or i1 %not_null, %no_underflow
   ret i1 %r
 }
+
+; The comparison can be with any of the values being added.
+define i1 @t9(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t9(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[BASE:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[OFFSET]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %cmp = icmp slt i8 %base, 0
+  call void @llvm.assume(i1 %cmp)
+
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ult i8 %adjusted, %offset
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}

diff --git a/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll
new file mode 100644 (file)
index 0000000..abf8f9b
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/result-of-add-of-negative-or-zero-is-non-zero-and-no-underflow.ll
@@ -0,0 +1,166 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+declare void @use8(i8)
+
+declare void @use1(i1)
+declare void @llvm.assume(i1)
+
+define i1 @t0(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t0(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ule i8 %adjusted, %base
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}
+
+; We need to produce extra instruction, so one of icmp's must go away.
+define i1 @t1_oneuse0(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t1_oneuse0(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    call void @use1(i1 [[NOT_NULL]])
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  call void @use1(i1 %not_null)
+  %no_underflow = icmp ule i8 %adjusted, %base
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}
+define i1 @t2_oneuse1(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t2_oneuse1(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    call void @use1(i1 [[NO_UNDERFLOW]])
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ule i8 %adjusted, %base
+  call void @use1(i1 %no_underflow)
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}
+define i1 @n3_oneuse2_bad(i8 %base, i8 %offset) {
+; CHECK-LABEL: @n3_oneuse2_bad(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    call void @use1(i1 [[NOT_NULL]])
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    call void @use1(i1 [[NO_UNDERFLOW]])
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  call void @use1(i1 %not_null)
+  %no_underflow = icmp ule i8 %adjusted, %base
+  call void @use1(i1 %no_underflow)
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}
+
+define i1 @t4_commutativity0(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t4_commutativity0(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ule i8 %adjusted, %base
+  %r = and i1 %no_underflow, %not_null ; swapped
+  ret i1 %r
+}
+define i1 @t5_commutativity1(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t5_commutativity1(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ugt i8 %base, %adjusted ; swapped
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}
+define i1 @t6_commutativity3(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t6_commutativity3(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ult i8 [[ADJUSTED]], [[BASE]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NO_UNDERFLOW]], [[NOT_NULL]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ugt i8 %base, %adjusted ; swapped
+  %r = and i1 %no_underflow, %not_null ; swapped
+  ret i1 %r
+}
+
+; We could have the opposite question, did we get null or overflow happened?
+define i1 @t7(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t7(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[TMP1:%.*]] = add i8 [[ADJUSTED]], -1
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp uge i8 [[TMP1]], [[BASE]]
+; CHECK-NEXT:    ret i1 [[TMP2]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp eq i8 %adjusted, 0
+  %no_underflow = icmp ugt i8 %adjusted, %base
+  %r = or i1 %not_null, %no_underflow
+  ret i1 %r
+}
+
+; The comparison can be with any of the values being added.
+define i1 @t8(i8 %base, i8 %offset) {
+; CHECK-LABEL: @t8(
+; CHECK-NEXT:    [[ADJUSTED:%.*]] = add i8 [[BASE:%.*]], [[OFFSET:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[ADJUSTED]])
+; CHECK-NEXT:    [[NOT_NULL:%.*]] = icmp ne i8 [[ADJUSTED]], 0
+; CHECK-NEXT:    [[NO_UNDERFLOW:%.*]] = icmp ule i8 [[ADJUSTED]], [[OFFSET]]
+; CHECK-NEXT:    [[R:%.*]] = and i1 [[NOT_NULL]], [[NO_UNDERFLOW]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %adjusted = add i8 %base, %offset
+  call void @use8(i8 %adjusted)
+  %not_null = icmp ne i8 %adjusted, 0
+  %no_underflow = icmp ule i8 %adjusted, %offset
+  %r = and i1 %not_null, %no_underflow
+  ret i1 %r
+}