llvm-6502/lib/CodeGen/Passes.cpp
Jakob Stoklund Olesen 700bfada63 Add a -regalloc=default option that chooses a register allocator based on the -O
optimization level.

This only really affects llc for now because both the llvm-gcc and clang front
ends override the default register allocator. I intend to remove that code later.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104904 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-27 23:57:25 +00:00

69 lines
2.3 KiB
C++

//===-- Passes.cpp - Target independent code generation passes ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines interfaces to access the target independent code
// generation passes provided by the LLVM backend.
//
//===---------------------------------------------------------------------===//
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/CodeGen/Passes.h"
using namespace llvm;
//===---------------------------------------------------------------------===//
///
/// RegisterRegAlloc class - Track the registration of register allocators.
///
//===---------------------------------------------------------------------===//
MachinePassRegistry RegisterRegAlloc::Registry;
static FunctionPass *createDefaultRegisterAllocator() { return 0; }
static RegisterRegAlloc
defaultRegAlloc("default",
"pick register allocator based on -O option",
createDefaultRegisterAllocator);
//===---------------------------------------------------------------------===//
///
/// RegAlloc command line options.
///
//===---------------------------------------------------------------------===//
static cl::opt<RegisterRegAlloc::FunctionPassCtor, false,
RegisterPassParser<RegisterRegAlloc> >
RegAlloc("regalloc",
cl::init(&createDefaultRegisterAllocator),
cl::desc("Register allocator to use"));
//===---------------------------------------------------------------------===//
///
/// createRegisterAllocator - choose the appropriate register allocator.
///
//===---------------------------------------------------------------------===//
FunctionPass *llvm::createRegisterAllocator(CodeGenOpt::Level OptLevel) {
RegisterRegAlloc::FunctionPassCtor Ctor = RegisterRegAlloc::getDefault();
if (!Ctor) {
Ctor = RegAlloc;
RegisterRegAlloc::setDefault(RegAlloc);
}
if (Ctor != createDefaultRegisterAllocator)
return Ctor();
// When the 'default' allocator is requested, pick one based on OptLevel.
switch (OptLevel) {
case CodeGenOpt::None:
return createLocalRegisterAllocator();
default:
return createLinearScanRegisterAllocator();
}
}