diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 4ecacf9d0108..a9aab86abdac 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -930,6 +930,18 @@ optimized with "clang -emit-llvm-bc | opt -std-compile-opts". //===---------------------------------------------------------------------===// +int g(int x) { return (x - 10) < 0; } +Should combine to "x <= 9" (the sub has nsw). Currently not +optimized with "clang -emit-llvm-bc | opt -std-compile-opts". + +//===---------------------------------------------------------------------===// + +int g(int x) { return (x + 10) < 0; } +Should combine to "x < -10" (the add has nsw). Currently not +optimized with "clang -emit-llvm-bc | opt -std-compile-opts". + +//===---------------------------------------------------------------------===// + int f(int i, int j) { return i < j + 1; } int g(int i, int j) { return j > i - 1; } Should combine to "i <= j" (the add/sub has nsw). Currently not diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index fea0d0245c81..8c0ad525980a 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3008,20 +3008,6 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // icmp X, X+Cst if (match(Op1, m_Add(m_Value(X), m_ConstantInt(Cst))) && Op0 == X) return FoldICmpAddOpCst(I, X, Cst, I.getSwappedPredicate()); - - ConstantInt *Cst2; - if (I.isSigned() && - match(Op1, m_ConstantInt(Cst)) && - match(Op0, m_Add(m_Value(X), m_ConstantInt(Cst2))) && - cast(Op0)->hasNoSignedWrap()) { - // icmp X+Cst2, Cst --> icmp X, Cst-Cst2 - // iff Cst-Cst2 does not overflow - bool Overflow; - APInt NewCst = Cst->getValue().ssub_ov(Cst2->getValue(), Overflow); - if (!Overflow) - return new ICmpInst(I.getPredicate(), X, - ConstantInt::get(Cst->getType(), NewCst)); - } } return Changed ? &I : 0; } diff --git a/test/Transforms/InstCombine/icmp.ll b/test/Transforms/InstCombine/icmp.ll index 63fefc087766..12a4744cc0fe 100644 --- a/test/Transforms/InstCombine/icmp.ll +++ b/test/Transforms/InstCombine/icmp.ll @@ -1356,66 +1356,3 @@ define i1 @icmp_ashr_ashr_ne(i32 %a, i32 %b) nounwind { %z = icmp ne i32 %x, %y ret i1 %z } - -; CHECK-LABEL: icmp_add_const_const1 -; CHECK: %cmp = icmp slt i32 %x, -10 -; CHECK-NOT: %add = add nsw i32 %x, 10 -define i32 @icmp_add_const_const1(i32 %x) nounwind ssp uwtable { -entry: - %add = add nsw i32 %x, 10 - %cmp = icmp slt i32 %add, 0 - %conv = zext i1 %cmp to i32 - ret i32 %conv -} - -; CHECK-LABEL: icmp_add_const_const2 -; CHECK: %cmp = icmp slt i32 %x, -10 -; CHECK-NOT: %add = add nsw i32 %x, 10 -define i32 @icmp_add_const_const2(i32 %x) nounwind ssp uwtable { -entry: - %add = add nsw i32 10, %x - %cmp = icmp sgt i32 0, %add - %conv = zext i1 %cmp to i32 - ret i32 %conv -} - -; CHECK-LABEL: icmp_add_const_const3 -; CHECK: %cmp = icmp slt i32 %x, 20 -; CHECK-NOT: %sub = add nsw i32 %x, -10 -define i32 @icmp_add_const_const3(i32 %x) nounwind ssp uwtable { -entry: - %add = add nsw i32 -10, %x - %cmp = icmp sgt i32 10, %add - %conv = zext i1 %cmp to i32 - ret i32 %conv -} - -; CHECK-LABEL: icmp_add_const_intmin -; CHECK: %cmp = icmp ne i32 %x, 2147483638 -define i32 @icmp_add_const_intmin(i32 %x) nounwind ssp uwtable { -entry: - %add = add nsw i32 %x, 10 - %cmp = icmp sgt i32 %add, -2147483648 - %conv = zext i1 %cmp to i32 - ret i32 %conv -} - -; CHECK-LABEL: icmp_add_const_intmax -; CHECK: %cmp = icmp ne i32 %x, 2147483637 -define i32 @icmp_add_const_intmax(i32 %x) nounwind ssp uwtable { -entry: - %add = add nsw i32 %x, 10 - %cmp = icmp slt i32 %add, 2147483647 - %conv = zext i1 %cmp to i32 - ret i32 %conv -} - -; CHECK-LABEL: icmp_add_const_ult -; CHECK: %cmp = icmp ult i32 %add, 6 -define i32 @icmp_add_const_ult(i32 %a) #0 { -entry: - %add = add nsw i32 %a, -49 - %cmp = icmp ult i32 %add, 6 - %conv = zext i1 %cmp to i32 - ret i32 %conv -}