forked from OSchip/llvm-project
119 lines
4.2 KiB
C++
119 lines
4.2 KiB
C++
//===-- NVPTXLowerAlloca.cpp - Make alloca to use local memory =====--===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// For all alloca instructions, and add a pair of cast to local address for
|
|
// each of them. For example,
|
|
//
|
|
// %A = alloca i32
|
|
// store i32 0, i32* %A ; emits st.u32
|
|
//
|
|
// will be transformed to
|
|
//
|
|
// %A = alloca i32
|
|
// %Local = addrspacecast i32* %A to i32 addrspace(5)*
|
|
// %Generic = addrspacecast i32 addrspace(5)* %A to i32*
|
|
// store i32 0, i32 addrspace(5)* %Generic ; emits st.local.u32
|
|
//
|
|
// And we will rely on NVPTXFavorNonGenericAddrSpace to combine the last
|
|
// two instructions.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "NVPTX.h"
|
|
#include "NVPTXUtilities.h"
|
|
#include "llvm/IR/Function.h"
|
|
#include "llvm/IR/Instructions.h"
|
|
#include "llvm/IR/IntrinsicInst.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/IR/Type.h"
|
|
#include "llvm/Pass.h"
|
|
|
|
using namespace llvm;
|
|
|
|
namespace llvm {
|
|
void initializeNVPTXLowerAllocaPass(PassRegistry &);
|
|
}
|
|
|
|
namespace {
|
|
class NVPTXLowerAlloca : public BasicBlockPass {
|
|
bool runOnBasicBlock(BasicBlock &BB) override;
|
|
|
|
public:
|
|
static char ID; // Pass identification, replacement for typeid
|
|
NVPTXLowerAlloca() : BasicBlockPass(ID) {}
|
|
StringRef getPassName() const override {
|
|
return "convert address space of alloca'ed memory to local";
|
|
}
|
|
};
|
|
} // namespace
|
|
|
|
char NVPTXLowerAlloca::ID = 1;
|
|
|
|
INITIALIZE_PASS(NVPTXLowerAlloca, "nvptx-lower-alloca",
|
|
"Lower Alloca", false, false)
|
|
|
|
// =============================================================================
|
|
// Main function for this pass.
|
|
// =============================================================================
|
|
bool NVPTXLowerAlloca::runOnBasicBlock(BasicBlock &BB) {
|
|
if (skipBasicBlock(BB))
|
|
return false;
|
|
|
|
bool Changed = false;
|
|
for (auto &I : BB) {
|
|
if (auto allocaInst = dyn_cast<AllocaInst>(&I)) {
|
|
Changed = true;
|
|
auto PTy = dyn_cast<PointerType>(allocaInst->getType());
|
|
auto ETy = PTy->getElementType();
|
|
auto LocalAddrTy = PointerType::get(ETy, ADDRESS_SPACE_LOCAL);
|
|
auto NewASCToLocal = new AddrSpaceCastInst(allocaInst, LocalAddrTy, "");
|
|
auto GenericAddrTy = PointerType::get(ETy, ADDRESS_SPACE_GENERIC);
|
|
auto NewASCToGeneric = new AddrSpaceCastInst(NewASCToLocal,
|
|
GenericAddrTy, "");
|
|
NewASCToLocal->insertAfter(allocaInst);
|
|
NewASCToGeneric->insertAfter(NewASCToLocal);
|
|
for (Value::use_iterator UI = allocaInst->use_begin(),
|
|
UE = allocaInst->use_end();
|
|
UI != UE; ) {
|
|
// Check Load, Store, GEP, and BitCast Uses on alloca and make them
|
|
// use the converted generic address, in order to expose non-generic
|
|
// addrspacecast to NVPTXFavorNonGenericAddrSpace. For other types
|
|
// of instructions this is unnecessary and may introduce redundant
|
|
// address cast.
|
|
const auto &AllocaUse = *UI++;
|
|
auto LI = dyn_cast<LoadInst>(AllocaUse.getUser());
|
|
if (LI && LI->getPointerOperand() == allocaInst && !LI->isVolatile()) {
|
|
LI->setOperand(LI->getPointerOperandIndex(), NewASCToGeneric);
|
|
continue;
|
|
}
|
|
auto SI = dyn_cast<StoreInst>(AllocaUse.getUser());
|
|
if (SI && SI->getPointerOperand() == allocaInst && !SI->isVolatile()) {
|
|
SI->setOperand(SI->getPointerOperandIndex(), NewASCToGeneric);
|
|
continue;
|
|
}
|
|
auto GI = dyn_cast<GetElementPtrInst>(AllocaUse.getUser());
|
|
if (GI && GI->getPointerOperand() == allocaInst) {
|
|
GI->setOperand(GI->getPointerOperandIndex(), NewASCToGeneric);
|
|
continue;
|
|
}
|
|
auto BI = dyn_cast<BitCastInst>(AllocaUse.getUser());
|
|
if (BI && BI->getOperand(0) == allocaInst) {
|
|
BI->setOperand(0, NewASCToGeneric);
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return Changed;
|
|
}
|
|
|
|
BasicBlockPass *llvm::createNVPTXLowerAllocaPass() {
|
|
return new NVPTXLowerAlloca();
|
|
}
|