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-rw-r--r--llvm/lib/Target/ARM/ARMGlobalMerge.cpp219
-rw-r--r--llvm/lib/Target/ARM/ARMTargetMachine.cpp3
2 files changed, 2 insertions, 220 deletions
diff --git a/llvm/lib/Target/ARM/ARMGlobalMerge.cpp b/llvm/lib/Target/ARM/ARMGlobalMerge.cpp
deleted file mode 100644
index 5f863ea241c..00000000000
--- a/llvm/lib/Target/ARM/ARMGlobalMerge.cpp
+++ /dev/null
@@ -1,219 +0,0 @@
-//===-- ARMGlobalMerge.cpp - Internal globals merging --------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// This pass merges globals with internal linkage into one. This way all the
-// globals which were merged into a biggest one can be addressed using offsets
-// from the same base pointer (no need for separate base pointer for each of the
-// global). Such a transformation can significantly reduce the register pressure
-// when many globals are involved.
-//
-// For example, consider the code which touches several global variables at
-// once:
-//
-// static int foo[N], bar[N], baz[N];
-//
-// for (i = 0; i < N; ++i) {
-// foo[i] = bar[i] * baz[i];
-// }
-//
-// On ARM the addresses of 3 arrays should be kept in the registers, thus
-// this code has quite large register pressure (loop body):
-//
-// ldr r1, [r5], #4
-// ldr r2, [r6], #4
-// mul r1, r2, r1
-// str r1, [r0], #4
-//
-// Pass converts the code to something like:
-//
-// static struct {
-// int foo[N];
-// int bar[N];
-// int baz[N];
-// } merged;
-//
-// for (i = 0; i < N; ++i) {
-// merged.foo[i] = merged.bar[i] * merged.baz[i];
-// }
-//
-// and in ARM code this becomes:
-//
-// ldr r0, [r5, #40]
-// ldr r1, [r5, #80]
-// mul r0, r1, r0
-// str r0, [r5], #4
-//
-// note that we saved 2 registers here almostly "for free".
-// ===---------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "arm-global-merge"
-#include "ARM.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Attributes.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetLowering.h"
-#include "llvm/Target/TargetLoweringObjectFile.h"
-using namespace llvm;
-
-namespace {
- class ARMGlobalMerge : public FunctionPass {
- /// TLI - Keep a pointer of a TargetLowering to consult for determining
- /// target type sizes.
- const TargetLowering *TLI;
-
- bool doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
- Module &M, bool isConst) const;
-
- public:
- static char ID; // Pass identification, replacement for typeid.
- explicit ARMGlobalMerge(const TargetLowering *tli)
- : FunctionPass(ID), TLI(tli) {}
-
- virtual bool doInitialization(Module &M);
- virtual bool runOnFunction(Function &F);
-
- const char *getPassName() const {
- return "Merge internal globals";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesCFG();
- FunctionPass::getAnalysisUsage(AU);
- }
-
- struct GlobalCmp {
- const TargetData *TD;
-
- GlobalCmp(const TargetData *td) : TD(td) { }
-
- bool operator()(const GlobalVariable *GV1, const GlobalVariable *GV2) {
- Type *Ty1 = cast<PointerType>(GV1->getType())->getElementType();
- Type *Ty2 = cast<PointerType>(GV2->getType())->getElementType();
-
- return (TD->getTypeAllocSize(Ty1) < TD->getTypeAllocSize(Ty2));
- }
- };
- };
-} // end anonymous namespace
-
-char ARMGlobalMerge::ID = 0;
-
-bool ARMGlobalMerge::doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
- Module &M, bool isConst) const {
- const TargetData *TD = TLI->getTargetData();
-
- // FIXME: Infer the maximum possible offset depending on the actual users
- // (these max offsets are different for the users inside Thumb or ARM
- // functions)
- unsigned MaxOffset = TLI->getMaximalGlobalOffset();
-
- // FIXME: Find better heuristics
- std::stable_sort(Globals.begin(), Globals.end(), GlobalCmp(TD));
-
- Type *Int32Ty = Type::getInt32Ty(M.getContext());
-
- for (size_t i = 0, e = Globals.size(); i != e; ) {
- size_t j = 0;
- uint64_t MergedSize = 0;
- std::vector<Type*> Tys;
- std::vector<Constant*> Inits;
- for (j = i; j != e; ++j) {
- Type *Ty = Globals[j]->getType()->getElementType();
- MergedSize += TD->getTypeAllocSize(Ty);
- if (MergedSize > MaxOffset) {
- break;
- }
- Tys.push_back(Ty);
- Inits.push_back(Globals[j]->getInitializer());
- }
-
- StructType *MergedTy = StructType::get(M.getContext(), Tys);
- Constant *MergedInit = ConstantStruct::get(MergedTy, Inits);
- GlobalVariable *MergedGV = new GlobalVariable(M, MergedTy, isConst,
- GlobalValue::InternalLinkage,
- MergedInit, "_MergedGlobals");
- for (size_t k = i; k < j; ++k) {
- Constant *Idx[2] = {
- ConstantInt::get(Int32Ty, 0),
- ConstantInt::get(Int32Ty, k-i)
- };
- Constant *GEP = ConstantExpr::getInBoundsGetElementPtr(MergedGV, Idx);
- Globals[k]->replaceAllUsesWith(GEP);
- Globals[k]->eraseFromParent();
- }
- i = j;
- }
-
- return true;
-}
-
-
-bool ARMGlobalMerge::doInitialization(Module &M) {
- SmallVector<GlobalVariable*, 16> Globals, ConstGlobals, BSSGlobals;
- const TargetData *TD = TLI->getTargetData();
- unsigned MaxOffset = TLI->getMaximalGlobalOffset();
- bool Changed = false;
-
- // Grab all non-const globals.
- for (Module::global_iterator I = M.global_begin(),
- E = M.global_end(); I != E; ++I) {
- // Merge is safe for "normal" internal globals only
- if (!I->hasLocalLinkage() || I->isThreadLocal() || I->hasSection())
- continue;
-
- // Ignore fancy-aligned globals for now.
- unsigned Alignment = I->getAlignment();
- Type *Ty = I->getType()->getElementType();
- if (Alignment > TD->getABITypeAlignment(Ty))
- continue;
-
- // Ignore all 'special' globals.
- if (I->getName().startswith("llvm.") ||
- I->getName().startswith(".llvm."))
- continue;
-
- if (TD->getTypeAllocSize(Ty) < MaxOffset) {
- const TargetLoweringObjectFile &TLOF = TLI->getObjFileLowering();
- if (TLOF.getKindForGlobal(I, TLI->getTargetMachine()).isBSSLocal())
- BSSGlobals.push_back(I);
- else if (I->isConstant())
- ConstGlobals.push_back(I);
- else
- Globals.push_back(I);
- }
- }
-
- if (Globals.size() > 1)
- Changed |= doMerge(Globals, M, false);
- if (BSSGlobals.size() > 1)
- Changed |= doMerge(BSSGlobals, M, false);
-
- // FIXME: This currently breaks the EH processing due to way how the
- // typeinfo detection works. We might want to detect the TIs and ignore
- // them in the future.
- // if (ConstGlobals.size() > 1)
- // Changed |= doMerge(ConstGlobals, M, true);
-
- return Changed;
-}
-
-bool ARMGlobalMerge::runOnFunction(Function &F) {
- return false;
-}
-
-FunctionPass *llvm::createARMGlobalMergePass(const TargetLowering *tli) {
- return new ARMGlobalMerge(tli);
-}
diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.cpp b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
index 96b1e89b0df..cf1432d64f2 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
@@ -20,6 +20,7 @@
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetOptions.h"
+#include "llvm/Transforms/Scalar.h"
using namespace llvm;
static cl::opt<bool>
@@ -97,7 +98,7 @@ ThumbTargetMachine::ThumbTargetMachine(const Target &T, StringRef TT,
bool ARMBaseTargetMachine::addPreISel(PassManagerBase &PM,
CodeGenOpt::Level OptLevel) {
if (OptLevel != CodeGenOpt::None && EnableGlobalMerge)
- PM.add(createARMGlobalMergePass(getTargetLowering()));
+ PM.add(createGlobalMergePass(getTargetLowering()));
return false;
}
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