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author | Jingyue Wu <jingyue@google.com> | 2014-06-15 21:40:57 +0000 |
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committer | Jingyue Wu <jingyue@google.com> | 2014-06-15 21:40:57 +0000 |
commit | f6eb7e3175aa0bb69152196bff69beade5fb8f38 (patch) | |
tree | 4f815a74850babac547bcb3b1160935480d88c20 /lib/IR | |
parent | f9ef37a9861424efefcca5695c195521ccf31f4a (diff) | |
download | llvm-f6eb7e3175aa0bb69152196bff69beade5fb8f38.tar.gz llvm-f6eb7e3175aa0bb69152196bff69beade5fb8f38.tar.bz2 llvm-f6eb7e3175aa0bb69152196bff69beade5fb8f38.tar.xz |
Canonicalize addrspacecast ConstExpr between different pointer types
As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.
Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.
Piggyback a minor refactor in InstCombineCasts.cpp
Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211004 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/IR')
-rw-r--r-- | lib/IR/ConstantFold.cpp | 5 | ||||
-rw-r--r-- | lib/IR/Constants.cpp | 13 |
2 files changed, 17 insertions, 1 deletions
diff --git a/lib/IR/ConstantFold.cpp b/lib/IR/ConstantFold.cpp index 706e66fb42..c23ab71eaf 100644 --- a/lib/IR/ConstantFold.cpp +++ b/lib/IR/ConstantFold.cpp @@ -529,7 +529,10 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V, // Try hard to fold cast of cast because they are often eliminable. if (unsigned newOpc = foldConstantCastPair(opc, CE, DestTy)) return ConstantExpr::getCast(newOpc, CE->getOperand(0), DestTy); - } else if (CE->getOpcode() == Instruction::GetElementPtr) { + } else if (CE->getOpcode() == Instruction::GetElementPtr && + // Do not fold addrspacecast (gep 0, .., 0). It might make the + // addrspacecast uncanonicalized. + opc != Instruction::AddrSpaceCast) { // If all of the indexes in the GEP are null values, there is no pointer // adjustment going on. We might as well cast the source pointer. bool isAllNull = true; diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp index bb8d60b234..aa26cff6a7 100644 --- a/lib/IR/Constants.cpp +++ b/lib/IR/Constants.cpp @@ -1698,6 +1698,19 @@ Constant *ConstantExpr::getAddrSpaceCast(Constant *C, Type *DstTy) { assert(CastInst::castIsValid(Instruction::AddrSpaceCast, C, DstTy) && "Invalid constantexpr addrspacecast!"); + // Canonicalize addrspacecasts between different pointer types by first + // bitcasting the pointer type and then converting the address space. + PointerType *SrcScalarTy = cast<PointerType>(C->getType()->getScalarType()); + PointerType *DstScalarTy = cast<PointerType>(DstTy->getScalarType()); + Type *DstElemTy = DstScalarTy->getElementType(); + if (SrcScalarTy->getElementType() != DstElemTy) { + Type *MidTy = PointerType::get(DstElemTy, SrcScalarTy->getAddressSpace()); + if (VectorType *VT = dyn_cast<VectorType>(DstTy)) { + // Handle vectors of pointers. + MidTy = VectorType::get(MidTy, VT->getNumElements()); + } + C = getBitCast(C, MidTy); + } return getFoldedCast(Instruction::AddrSpaceCast, C, DstTy); } |