llvm-project/llvm/lib/Support/Memory.cpp

110 lines
3.9 KiB
C++

//===- Memory.cpp - Memory Handling Support ---------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines some helpful functions for allocating memory and dealing
// with memory mapped files
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Memory.h"
#include "llvm/Support/Valgrind.h"
#include "llvm/Config/config.h"
namespace llvm {
using namespace sys;
}
// Include the platform-specific parts of this class.
#ifdef LLVM_ON_UNIX
#include "Unix/Memory.inc"
#endif
#ifdef LLVM_ON_WIN32
#include "Windows/Memory.inc"
#endif
extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
/// ClearMipsCache - Invalidates instruction cache for Mips. This assembly code
/// is copied from the MIPS32 Instruction Set Reference. Since the code ends
/// with the return instruction "jr.hb ra" (Jump Register with Hazard Barrier),
/// it must be implemented as a function (which is called from the
/// InvalidateInstructionCache function). It cannot be directly inlined into
/// InvalidateInstructionCache function, because in that case the epilog of
/// InvalidateInstructionCache will not be executed.
#if defined(__mips__)
extern "C" void ClearMipsCache(const void* Addr, size_t Size);
asm volatile(
".text\n"
".align 2\n"
".globl ClearMipsCache\n"
"ClearMipsCache:\n"
".set noreorder\n"
"beq $a1, $zero, 20f\n" /* If size==0, branch around */
"nop\n"
"addu $a1, $a0, $a1\n" /* Calculate end address + 1 */
"rdhwr $v0, $1\n" /* Get step size for SYNCI */
/* $1 is $HW_SYNCI_Step */
"beq $v0, $zero, 20f\n" /* If no caches require synchronization, */
/* branch around */
"nop\n"
"10: synci 0($a0)\n" /* Synchronize all caches around address */
"sltu $v1, $a0, $a1\n" /* Compare current with end address */
"bne $v1, $zero, 10b\n" /* Branch if more to do */
"addu $a0, $a0, $v0\n" /* Add step size in delay slot */
"sync\n" /* Clear memory hazards */
"20: jr.hb $ra\n" /* Return, clearing instruction hazards */
"nop\n"
);
#endif
/// InvalidateInstructionCache - Before the JIT can run a block of code
/// that has been emitted it must invalidate the instruction cache on some
/// platforms.
void llvm::sys::Memory::InvalidateInstructionCache(const void *Addr,
size_t Len) {
// icache invalidation for PPC and ARM.
#if defined(__APPLE__)
# if (defined(__POWERPC__) || defined (__ppc__) || \
defined(_POWER) || defined(_ARCH_PPC)) || defined(__arm__)
sys_icache_invalidate(Addr, Len);
# endif
#else
# if (defined(__POWERPC__) || defined (__ppc__) || \
defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
const size_t LineSize = 32;
const intptr_t Mask = ~(LineSize - 1);
const intptr_t StartLine = ((intptr_t) Addr) & Mask;
const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
asm volatile("dcbf 0, %0" : : "r"(Line));
asm volatile("sync");
for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
asm volatile("icbi 0, %0" : : "r"(Line));
asm volatile("isync");
# elif defined(__arm__) && defined(__GNUC__)
// FIXME: Can we safely always call this for __GNUC__ everywhere?
char *Start = (char*) Addr;
char *End = Start + Len;
__clear_cache(Start, End);
# elif defined(__mips__)
ClearMipsCache(Addr, Len);
# endif
#endif // end apple
ValgrindDiscardTranslations(Addr, Len);
}