llvm-6502/include/llvm/CodeGen/LinkAllCodegenComponents.h

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//===- llvm/Codegen/LinkAllCodegenComponents.h ------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header file pulls in all codegen related passes for tools like lli and
// llc that need this functionality.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_LINKALLCODEGENCOMPONENTS_H
#define LLVM_CODEGEN_LINKALLCODEGENCOMPONENTS_H
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/SchedulerRegistry.h"
#include "llvm/CodeGen/GCs.h"
#include "llvm/Target/TargetMachine.h"
#include <cstdlib>
namespace {
struct ForceCodegenLinking {
ForceCodegenLinking() {
// We must reference the passes in such a way that compilers will not
// delete it all as dead code, even with whole program optimization,
// yet is effectively a NO-OP. As the compiler isn't smart enough
// to know that getenv() never returns -1, this will do the job.
if (std::getenv("bar") != (char*) -1)
return;
(void) llvm::createDeadMachineInstructionElimPass();
(void) llvm::createLocalRegisterAllocator();
(void) llvm::createLinearScanRegisterAllocator();
(void) llvm::createPBQPRegisterAllocator();
(void) llvm::createSimpleRegisterCoalescer();
llvm::linkOcamlGC();
llvm::linkShadowStackGC();
With this patch, the LowerGC transformation becomes the ShadowStackCollector, which additionally has reduced overhead with no sacrifice in portability. Considering a function @fun with 8 loop-local roots, ShadowStackCollector introduces the following overhead (x86): ; shadowstack prologue movl L_llvm_gc_root_chain$non_lazy_ptr, %eax movl (%eax), %ecx movl $___gc_fun, 20(%esp) movl $0, 24(%esp) movl $0, 28(%esp) movl $0, 32(%esp) movl $0, 36(%esp) movl $0, 40(%esp) movl $0, 44(%esp) movl $0, 48(%esp) movl $0, 52(%esp) movl %ecx, 16(%esp) leal 16(%esp), %ecx movl %ecx, (%eax) ; shadowstack loop overhead (none) ; shadowstack epilogue movl 48(%esp), %edx movl %edx, (%ecx) ; shadowstack metadata .align 3 ___gc_fun: # __gc_fun .long 8 .space 4 In comparison to LowerGC: ; lowergc prologue movl L_llvm_gc_root_chain$non_lazy_ptr, %eax movl (%eax), %ecx movl %ecx, 48(%esp) movl $8, 52(%esp) movl $0, 60(%esp) movl $0, 56(%esp) movl $0, 68(%esp) movl $0, 64(%esp) movl $0, 76(%esp) movl $0, 72(%esp) movl $0, 84(%esp) movl $0, 80(%esp) movl $0, 92(%esp) movl $0, 88(%esp) movl $0, 100(%esp) movl $0, 96(%esp) movl $0, 108(%esp) movl $0, 104(%esp) movl $0, 116(%esp) movl $0, 112(%esp) ; lowergc loop overhead leal 44(%esp), %eax movl %eax, 56(%esp) leal 40(%esp), %eax movl %eax, 64(%esp) leal 36(%esp), %eax movl %eax, 72(%esp) leal 32(%esp), %eax movl %eax, 80(%esp) leal 28(%esp), %eax movl %eax, 88(%esp) leal 24(%esp), %eax movl %eax, 96(%esp) leal 20(%esp), %eax movl %eax, 104(%esp) leal 16(%esp), %eax movl %eax, 112(%esp) ; lowergc epilogue movl 48(%esp), %edx movl %edx, (%ecx) ; lowergc metadata (none) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45670 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-07 01:30:53 +00:00
(void) llvm::createBURRListDAGScheduler(NULL, llvm::CodeGenOpt::Default);
(void) llvm::createTDRRListDAGScheduler(NULL, llvm::CodeGenOpt::Default);
(void) llvm::createTDListDAGScheduler(NULL, llvm::CodeGenOpt::Default);
(void) llvm::createFastDAGScheduler(NULL, llvm::CodeGenOpt::Default);
(void) llvm::createDefaultScheduler(NULL, llvm::CodeGenOpt::Default);
}
} ForceCodegenLinking; // Force link by creating a global definition.
}
#endif