From b80a2a686fe76496d71397f8bdda394d5718ab01 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Tue, 23 Feb 2010 16:35:41 +0000 Subject: [PATCH] Remove the code which constant-folded ptrtoint(inttoptr(x)+c) to getelementptr. Despite only doing so in the case where x is a known array object and c can be converted to an index within range, this could still be invalid if c is actually the address of an object allocated outside of LLVM. Also, SCEVExpander, the original motivation for this code, has since been improved to avoid inttoptr+ptroint in more cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96950 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ConstantFolding.cpp | 42 +++---------------- .../InstCombine/constant-fold-ptr-casts.ll | 27 ------------ 2 files changed, 5 insertions(+), 64 deletions(-) delete mode 100644 test/Transforms/InstCombine/constant-fold-ptr-casts.ll diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 1d23fe0b6c9..114db2d3705 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -783,44 +783,12 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if // the int size is >= the ptr size. This requires knowing the width of a // pointer, so it can't be done in ConstantExpr::getCast. - if (ConstantExpr *CE = dyn_cast(Ops[0])) { + if (ConstantExpr *CE = dyn_cast(Ops[0])) if (TD && - TD->getPointerSizeInBits() <= - CE->getType()->getScalarSizeInBits()) { - if (CE->getOpcode() == Instruction::PtrToInt) - return FoldBitCast(CE->getOperand(0), DestTy, *TD); - - // If there's a constant offset added to the integer value before - // it is casted back to a pointer, see if the expression can be - // converted into a GEP. - if (CE->getOpcode() == Instruction::Add) - if (ConstantInt *L = dyn_cast(CE->getOperand(1))) - if (ConstantExpr *R = dyn_cast(CE->getOperand(0))) - if (R->getOpcode() == Instruction::PtrToInt) - if (GlobalVariable *GV = - dyn_cast(R->getOperand(0))) { - const PointerType *GVTy = cast(GV->getType()); - if (const ArrayType *AT = - dyn_cast(GVTy->getElementType())) { - const Type *ElTy = AT->getElementType(); - uint64_t AllocSize = TD->getTypeAllocSize(ElTy); - APInt PSA(L->getValue().getBitWidth(), AllocSize); - if (ElTy == cast(DestTy)->getElementType() && - L->getValue().urem(PSA) == 0) { - APInt ElemIdx = L->getValue().udiv(PSA); - if (ElemIdx.ult(APInt(ElemIdx.getBitWidth(), - AT->getNumElements()))) { - Constant *Index[] = { - Constant::getNullValue(CE->getType()), - ConstantInt::get(ElTy->getContext(), ElemIdx) - }; - return ConstantExpr::getGetElementPtr(GV, &Index[0], 2); - } - } - } - } - } - } + TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() && + CE->getOpcode() == Instruction::PtrToInt) + return FoldBitCast(CE->getOperand(0), DestTy, *TD); + return ConstantExpr::getCast(Opcode, Ops[0], DestTy); case Instruction::Trunc: case Instruction::ZExt: diff --git a/test/Transforms/InstCombine/constant-fold-ptr-casts.ll b/test/Transforms/InstCombine/constant-fold-ptr-casts.ll deleted file mode 100644 index 50954468b6f..00000000000 --- a/test/Transforms/InstCombine/constant-fold-ptr-casts.ll +++ /dev/null @@ -1,27 +0,0 @@ -; RUN: opt < %s -instcombine -S | grep {ret i32 2143034560} | count 2 - -; Instcombine should be able to completely fold this code. - -target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" -target triple = "i686-apple-darwin8" - -@bar = constant [3 x i64] [i64 9220983451228067448, i64 9220983451228067449, i64 9220983450959631991], align 8 - -define i32 @foo() nounwind { -entry: - %tmp87.2 = load i64* inttoptr (i32 add (i32 16, i32 ptrtoint ([3 x i64]* @bar to i32)) to i64*), align 8 - %t0 = bitcast i64 %tmp87.2 to double - %tmp9192.2 = fptrunc double %t0 to float - %t1 = bitcast float %tmp9192.2 to i32 - ret i32 %t1 -} - -define i32 @goo() nounwind { -entry: - %tmp87.2 = load i64* inttoptr (i32 add (i32 ptrtoint ([3 x i64]* @bar to i32), i32 16) to i64*), align 8 - %t0 = bitcast i64 %tmp87.2 to double - %tmp9192.2 = fptrunc double %t0 to float - %t1 = bitcast float %tmp9192.2 to i32 - ret i32 %t1 -} - -- 2.34.1