From d4273abb69e487883a612d49025dda2fb40322cd Mon Sep 17 00:00:00 2001 From: Krzysztof Parzyszek Date: Fri, 26 Jan 2018 21:20:04 +0000 Subject: [Hexagon] Make sure that offset on globals matches alignment requirements A correctly aligned address may happen to be separated into a variable part and a constant part, where the constant part does not match the alignment needed in a load/store that uses this address. Such a constant cannot be used as an immediate offset in an indexed instruction. When lowering a global address, make sure that if there is an offset folded into the global, the offset is valid for all uses in load/store instructions. llvm-svn: 323562 --- llvm/lib/Target/Hexagon/HexagonISelLowering.cpp | 54 ++++++++++++++++++------- 1 file changed, 40 insertions(+), 14 deletions(-) (limited to 'llvm/lib') diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp index e2edccbc8d1..177567306fe 100644 --- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp +++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp @@ -1472,32 +1472,58 @@ HexagonTargetLowering::LowerGLOBALADDRESS(SDValue Op, SelectionDAG &DAG) const { SDLoc dl(Op); auto *GAN = cast(Op); auto PtrVT = getPointerTy(DAG.getDataLayout()); - auto *GV = GAN->getGlobal(); - int64_t Offset = GAN->getOffset(); + const GlobalValue *GV = GAN->getGlobal(); + int32_t Offset = GAN->getOffset(); + int32_t Addend = 0; + + unsigned GlobAlign = GV->getAlignment(); + if (GlobAlign != 0 && Offset % GlobAlign != 0) { + unsigned MinAlign = GlobAlign; + for (SDNode *U : GAN->uses()) { + if (auto *M = dyn_cast(U)) + MinAlign = std::min(MinAlign, M->getAlignment()); + } + assert(isPowerOf2_32(MinAlign)); + if (Offset % MinAlign != 0) { + Addend = Offset & (MinAlign-1); // Always non-negative. + Offset -= Addend; + } + } auto &HLOF = *HTM.getObjFileLowering(); Reloc::Model RM = HTM.getRelocationModel(); + SDValue Res; if (RM == Reloc::Static) { SDValue GA = DAG.getTargetGlobalAddress(GV, dl, PtrVT, Offset); const GlobalObject *GO = GV->getBaseObject(); if (GO && HLOF.isGlobalInSmallSection(GO, HTM)) - return DAG.getNode(HexagonISD::CONST32_GP, dl, PtrVT, GA); - return DAG.getNode(HexagonISD::CONST32, dl, PtrVT, GA); + Res = DAG.getNode(HexagonISD::CONST32_GP, dl, PtrVT, GA); + else + Res = DAG.getNode(HexagonISD::CONST32, dl, PtrVT, GA); + } else { + bool UsePCRel = HTM.shouldAssumeDSOLocal(*GV->getParent(), GV); + if (UsePCRel) { + SDValue GA = DAG.getTargetGlobalAddress(GV, dl, PtrVT, Offset, + HexagonII::MO_PCREL); + Res = DAG.getNode(HexagonISD::AT_PCREL, dl, PtrVT, GA); + } else { + // Use GOT index. + SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(PtrVT); + SDValue GA = DAG.getTargetGlobalAddress(GV, dl, PtrVT, 0, + HexagonII::MO_GOT); + SDValue Off = DAG.getConstant(Offset, dl, MVT::i32); + Res = DAG.getNode(HexagonISD::AT_GOT, dl, PtrVT, GOT, GA, Off); + } } - bool UsePCRel = getTargetMachine().shouldAssumeDSOLocal(*GV->getParent(), GV); - if (UsePCRel) { - SDValue GA = DAG.getTargetGlobalAddress(GV, dl, PtrVT, Offset, - HexagonII::MO_PCREL); - return DAG.getNode(HexagonISD::AT_PCREL, dl, PtrVT, GA); + assert(Res.getNode() != nullptr); + if (Addend != 0) { + SDValue A = DAG.getConstant(Addend, dl, MVT::i32); + Res = DAG.getNode(ISD::ADD, dl, MVT::i32, Res, A); } - // Use GOT index. - SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(PtrVT); - SDValue GA = DAG.getTargetGlobalAddress(GV, dl, PtrVT, 0, HexagonII::MO_GOT); - SDValue Off = DAG.getConstant(Offset, dl, MVT::i32); - return DAG.getNode(HexagonISD::AT_GOT, dl, PtrVT, GOT, GA, Off); + return Res; } // Specifies that for loads and stores VT can be promoted to PromotedLdStVT. -- cgit v1.2.3