From ae32815f9281a5a8d48014e180901fcdb658285a Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Sun, 7 Aug 2016 07:58:00 +0000 Subject: [rust-lang/llvm#47 1/4] [InstCombine] Infer inbounds on geps of allocas git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277950 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/InstCombine/InstructionCombining.cpp | 19 +++++++++++++++++++ test/Transforms/InstCombine/getelementptr.ll | 6 +++--- 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 377ccb9c37f7..31b5ad6ae8af 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -1898,6 +1898,25 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { } } + if (!GEP.isInBounds()) { + unsigned PtrWidth = + DL.getPointerSizeInBits(PtrOp->getType()->getPointerAddressSpace()); + APInt BasePtrOffset(PtrWidth, 0); + Value *UnderlyingPtrOp = + PtrOp->stripAndAccumulateInBoundsConstantOffsets(DL, + BasePtrOffset); + if (auto *AI = dyn_cast(UnderlyingPtrOp)) { + if (GEP.accumulateConstantOffset(DL, BasePtrOffset) && + BasePtrOffset.isNonNegative()) { + APInt AllocSize(PtrWidth, DL.getTypeAllocSize(AI->getAllocatedType())); + if (BasePtrOffset.ule(AllocSize)) { + return GetElementPtrInst::CreateInBounds( + PtrOp, makeArrayRef(Ops).slice(1), GEP.getName()); + } + } + } + } + return nullptr; } diff --git a/test/Transforms/InstCombine/getelementptr.ll b/test/Transforms/InstCombine/getelementptr.ll index 7446734e210c..14abd84fd18e 100644 --- a/test/Transforms/InstCombine/getelementptr.ll +++ b/test/Transforms/InstCombine/getelementptr.ll @@ -366,7 +366,7 @@ define i32 @test21() { %rval = load i32, i32* %pbobel ret i32 %rval ; CHECK-LABEL: @test21( -; CHECK: getelementptr %intstruct, %intstruct* %pbob1, i64 0, i32 0 +; CHECK: getelementptr inbounds %intstruct, %intstruct* %pbob1, i64 0, i32 0 } @@ -540,8 +540,8 @@ define i8* @test32(i8* %v) { %G = load i8*, i8** %F ret i8* %G ; CHECK-LABEL: @test32( -; CHECK: %D = getelementptr [4 x i8*], [4 x i8*]* %A, i64 0, i64 1 -; CHECK: %F = getelementptr [4 x i8*], [4 x i8*]* %A, i64 0, i64 2 +; CHECK: %D = getelementptr inbounds [4 x i8*], [4 x i8*]* %A, i64 0, i64 1 +; CHECK: %F = getelementptr inbounds [4 x i8*], [4 x i8*]* %A, i64 0, i64 2 } ; PR3290 -- 2.7.4 From d31c987130ff1bf9cea9a287195ecceda91c37d1 Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Sun, 7 Aug 2016 07:58:10 +0000 Subject: [rust-lang/llvm#47 2/4] [InstSimplify] Try hard to simplify pointer comparisons Simplify ptrtoint comparisons involving operands with different source types. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277951 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 10 ++++++++++ test/Transforms/InstSimplify/compare.ll | 13 +++++++++++++ 2 files changed, 23 insertions(+) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 7c6edbfca270..8b70d89d62cb 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -3092,6 +3092,16 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, if (LHS->getType()->isPointerTy()) if (auto *C = computePointerICmp(Q.DL, Q.TLI, Q.DT, Pred, Q.CxtI, LHS, RHS)) return C; + if (auto *CLHS = dyn_cast(LHS)) + if (auto *CRHS = dyn_cast(RHS)) + if (Q.DL.getTypeSizeInBits(CLHS->getPointerOperandType()) == + Q.DL.getTypeSizeInBits(CLHS->getType()) && + Q.DL.getTypeSizeInBits(CRHS->getPointerOperandType()) == + Q.DL.getTypeSizeInBits(CRHS->getType())) + if (auto *C = computePointerICmp(Q.DL, Q.TLI, Q.DT, Pred, Q.CxtI, + CLHS->getPointerOperand(), + CRHS->getPointerOperand())) + return C; if (GetElementPtrInst *GLHS = dyn_cast(LHS)) { if (GEPOperator *GRHS = dyn_cast(RHS)) { diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll index 9d6fd74ae56f..3e7316ec6b48 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -205,6 +205,19 @@ define i1 @gep16(i8* %ptr, i32 %a) { ; CHECK-NEXT: ret i1 false } +define i1 @gep17() { +; CHECK-LABEL: @gep17( + %alloca = alloca i32, align 4 + %bc = bitcast i32* %alloca to [4 x i8]* + %gep1 = getelementptr inbounds i32, i32* %alloca, i32 1 + %pti1 = ptrtoint i32* %gep1 to i32 + %gep2 = getelementptr inbounds [4 x i8], [4 x i8]* %bc, i32 0, i32 1 + %pti2 = ptrtoint i8* %gep2 to i32 + %cmp = icmp ugt i32 %pti1, %pti2 + ret i1 %cmp +; CHECK-NEXT: ret i1 true +} + define i1 @zext(i32 %x) { ; CHECK-LABEL: @zext( %e1 = zext i32 %x to i64 -- 2.7.4 From bd3e05cb1f5293635edff14fcf23cfc73985c977 Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Sun, 7 Aug 2016 07:58:12 +0000 Subject: [rust-lang/llvm#47 3/4] [InstSimplify] Fold gep (gep V, C), (sub 0, V) to C git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277952 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 20 ++++++++++++++++++++ test/Transforms/InstSimplify/compare.ll | 13 +++++++++++++ 2 files changed, 33 insertions(+) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 8b70d89d62cb..9d2a47957125 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -3597,6 +3597,26 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef Ops, } } + // gep (gep V, C), (sub 0, V) -> C + if (Q.DL.getTypeAllocSize(LastType) == 1 && + all_of(Ops.slice(1).drop_back(1), + [](Value *Idx) { return match(Idx, m_Zero()); })) { + unsigned PtrWidth = + Q.DL.getPointerSizeInBits(Ops[0]->getType()->getPointerAddressSpace()); + if (Q.DL.getTypeSizeInBits(Ops.back()->getType()) == PtrWidth) { + APInt BasePtrOffset(PtrWidth, 0); + Value *StrippedBasePtr = + Ops[0]->stripAndAccumulateInBoundsConstantOffsets(Q.DL, + BasePtrOffset); + + if (match(Ops.back(), + m_Sub(m_Zero(), m_PtrToInt(m_Specific(StrippedBasePtr))))) { + auto *CI = ConstantInt::get(GEPTy->getContext(), BasePtrOffset); + return ConstantExpr::getIntToPtr(CI, GEPTy); + } + } + } + // Check to see if this is constant foldable. for (unsigned i = 0, e = Ops.size(); i != e; ++i) if (!isa(Ops[i])) diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll index 3e7316ec6b48..addb63c57222 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -218,6 +218,19 @@ define i1 @gep17() { ; CHECK-NEXT: ret i1 true } +define i32 @gep18() { +; CHECK-LABEL: @gep18( + %alloca = alloca i32, align 4 ; alloca + 0 + %gep = getelementptr inbounds i32, i32* %alloca, i32 1 ; alloca + 4 + %bc = bitcast i32* %gep to [4 x i8]* ; alloca + 4 + %pti = ptrtoint i32* %alloca to i32 ; alloca + %sub = sub i32 0, %pti ; -alloca + %add = getelementptr [4 x i8], [4 x i8]* %bc, i32 0, i32 %sub ; alloca + 4 - alloca == 4 + %add_to_int = ptrtoint i8* %add to i32 ; 4 + ret i32 %add_to_int ; 4 +; CHECK-NEXT: ret i32 4 +} + define i1 @zext(i32 %x) { ; CHECK-LABEL: @zext( %e1 = zext i32 %x to i64 -- 2.7.4 From c3eb3c7608f439231d0c1340af6b720f113b4bf4 Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Tue, 16 Aug 2016 06:13:46 +0000 Subject: [rust-lang/llvm#47 4/4] [InstSimplify] Fold gep (gep V, C), (xor V, -1) to C-1 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278779 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 8 +++++++- test/Transforms/InstSimplify/compare.ll | 13 ------------- 2 files changed, 7 insertions(+), 14 deletions(-) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 9d2a47957125..f7a435d1ad46 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -3597,7 +3597,6 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef Ops, } } - // gep (gep V, C), (sub 0, V) -> C if (Q.DL.getTypeAllocSize(LastType) == 1 && all_of(Ops.slice(1).drop_back(1), [](Value *Idx) { return match(Idx, m_Zero()); })) { @@ -3609,11 +3608,18 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef Ops, Ops[0]->stripAndAccumulateInBoundsConstantOffsets(Q.DL, BasePtrOffset); + // gep (gep V, C), (sub 0, V) -> C if (match(Ops.back(), m_Sub(m_Zero(), m_PtrToInt(m_Specific(StrippedBasePtr))))) { auto *CI = ConstantInt::get(GEPTy->getContext(), BasePtrOffset); return ConstantExpr::getIntToPtr(CI, GEPTy); } + // gep (gep V, C), (xor V, -1) -> C-1 + if (match(Ops.back(), + m_Xor(m_PtrToInt(m_Specific(StrippedBasePtr)), m_AllOnes()))) { + auto *CI = ConstantInt::get(GEPTy->getContext(), BasePtrOffset - 1); + return ConstantExpr::getIntToPtr(CI, GEPTy); + } } } diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll index addb63c57222..3e7316ec6b48 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -218,19 +218,6 @@ define i1 @gep17() { ; CHECK-NEXT: ret i1 true } -define i32 @gep18() { -; CHECK-LABEL: @gep18( - %alloca = alloca i32, align 4 ; alloca + 0 - %gep = getelementptr inbounds i32, i32* %alloca, i32 1 ; alloca + 4 - %bc = bitcast i32* %gep to [4 x i8]* ; alloca + 4 - %pti = ptrtoint i32* %alloca to i32 ; alloca - %sub = sub i32 0, %pti ; -alloca - %add = getelementptr [4 x i8], [4 x i8]* %bc, i32 0, i32 %sub ; alloca + 4 - alloca == 4 - %add_to_int = ptrtoint i8* %add to i32 ; 4 - ret i32 %add_to_int ; 4 -; CHECK-NEXT: ret i32 4 -} - define i1 @zext(i32 %x) { ; CHECK-LABEL: @zext( %e1 = zext i32 %x to i64 -- 2.7.4