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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "jit/arm/Architecture-arm.h"
#if !defined(JS_ARM_SIMULATOR) && !defined(__APPLE__)
#include <elf.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#include "jit/arm/Assembler-arm.h"
#include "jit/RegisterSets.h"
#if !defined(__linux__) || defined(ANDROID) || defined(JS_SIMULATOR_ARM)
// The Android NDK and B2G do not include the hwcap.h kernel header, and it is not
// defined when building the simulator, so inline the header defines we need.
# define HWCAP_VFP (1 << 6)
# define HWCAP_NEON (1 << 12)
# define HWCAP_VFPv3 (1 << 13)
# define HWCAP_VFPv3D16 (1 << 14) /* also set for VFPv4-D16 */
# define HWCAP_VFPv4 (1 << 16)
# define HWCAP_IDIVA (1 << 17)
# define HWCAP_IDIVT (1 << 18)
# define HWCAP_VFPD32 (1 << 19) /* set if VFP has 32 regs (not 16) */
# define AT_HWCAP 16
#else
# include <asm/hwcap.h>
# if !defined(HWCAP_IDIVA)
# define HWCAP_IDIVA (1 << 17)
# endif
# if !defined(HWCAP_VFPD32)
# define HWCAP_VFPD32 (1 << 19) /* set if VFP has 32 regs (not 16) */
# endif
#endif
namespace js {
namespace jit {
// Parse the Linux kernel cpuinfo features. This is also used to parse the
// override features which has some extensions: 'armv7', 'align' and 'hardfp'.
static uint32_t
ParseARMCpuFeatures(const char* features, bool override = false)
{
uint32_t flags = 0;
for (;;) {
char ch = *features;
if (!ch) {
// End of string.
break;
}
if (ch == ' ' || ch == ',') {
// Skip separator characters.
features++;
continue;
}
// Find the end of the token.
const char* end = features + 1;
for (; ; end++) {
ch = *end;
if (!ch || ch == ' ' || ch == ',')
break;
}
size_t count = end - features;
if (count == 3 && strncmp(features, "vfp", 3) == 0)
flags |= HWCAP_VFP;
else if (count == 4 && strncmp(features, "neon", 4) == 0)
flags |= HWCAP_NEON;
else if (count == 5 && strncmp(features, "vfpv3", 5) == 0)
flags |= HWCAP_VFPv3;
else if (count == 8 && strncmp(features, "vfpv3d16", 8) == 0)
flags |= HWCAP_VFPv3D16;
else if (count == 5 && strncmp(features, "vfpv4", 5) == 0)
flags |= HWCAP_VFPv4;
else if (count == 5 && strncmp(features, "idiva", 5) == 0)
flags |= HWCAP_IDIVA;
else if (count == 5 && strncmp(features, "idivt", 5) == 0)
flags |= HWCAP_IDIVT;
else if (count == 6 && strncmp(features, "vfpd32", 6) == 0)
flags |= HWCAP_VFPD32;
else if (count == 5 && strncmp(features, "armv7", 5) == 0)
flags |= HWCAP_ARMv7;
else if (count == 5 && strncmp(features, "align", 5) == 0)
flags |= HWCAP_ALIGNMENT_FAULT;
#if defined(JS_SIMULATOR_ARM)
else if (count == 6 && strncmp(features, "hardfp", 6) == 0)
flags |= HWCAP_USE_HARDFP_ABI;
#endif
else if (override)
fprintf(stderr, "Warning: unexpected ARM feature at: %s\n", features);
features = end;
}
return flags;
}
static uint32_t
CanonicalizeARMHwCapFlags(uint32_t flags)
{
// Canonicalize the flags. These rules are also applied to the features
// supplied for simulation.
// The VFPv3 feature is expected when the VFPv3D16 is reported, but add it
// just in case of a kernel difference in feature reporting.
if (flags & HWCAP_VFPv3D16)
flags |= HWCAP_VFPv3;
// If VFPv3 or Neon is supported then this must be an ARMv7.
if (flags & (HWCAP_VFPv3 | HWCAP_NEON))
flags |= HWCAP_ARMv7;
// Some old kernels report VFP and not VFPv3, but if ARMv7 then it must be
// VFPv3.
if (flags & HWCAP_VFP && flags & HWCAP_ARMv7)
flags |= HWCAP_VFPv3;
// Older kernels do not implement the HWCAP_VFPD32 flag.
if ((flags & HWCAP_VFPv3) && !(flags & HWCAP_VFPv3D16))
flags |= HWCAP_VFPD32;
return flags;
}
// The override flags parsed from the ARMHWCAP environment variable or from the
// --arm-hwcap js shell argument.
volatile uint32_t armHwCapFlags = HWCAP_UNINITIALIZED;
bool
ParseARMHwCapFlags(const char* armHwCap)
{
uint32_t flags = 0;
if (!armHwCap)
return false;
if (strstr(armHwCap, "help")) {
fflush(NULL);
printf(
"\n"
"usage: ARMHWCAP=option,option,option,... where options can be:\n"
"\n"
" vfp \n"
" neon \n"
" vfpv3 \n"
" vfpv3d16 \n"
" vfpv4 \n"
" idiva \n"
" idivt \n"
" vfpd32 \n"
" armv7 \n"
" align \n"
#ifdef JS_SIMULATOR_ARM
" hardfp \n"
#endif
"\n"
);
exit(0);
/*NOTREACHED*/
}
flags = ParseARMCpuFeatures(armHwCap, /* override = */ true);
#ifdef JS_CODEGEN_ARM_HARDFP
flags |= HWCAP_USE_HARDFP_ABI;
#endif
armHwCapFlags = CanonicalizeARMHwCapFlags(flags);
JitSpew(JitSpew_Codegen, "ARM HWCAP: 0x%x\n", armHwCapFlags);
return true;
}
void
InitARMFlags()
{
uint32_t flags = 0;
if (armHwCapFlags != HWCAP_UNINITIALIZED)
return;
const char* env = getenv("ARMHWCAP");
if (ParseARMHwCapFlags(env))
return;
#ifdef JS_SIMULATOR_ARM
flags = HWCAP_ARMv7 | HWCAP_VFP | HWCAP_VFPv3 | HWCAP_VFPv4 | HWCAP_NEON;
#else
#if defined(__linux__)
// This includes Android and B2G.
bool readAuxv = false;
int fd = open("/proc/self/auxv", O_RDONLY);
if (fd > 0) {
struct { uint32_t a_type; uint32_t a_val; } aux;
while (read(fd, &aux, sizeof(aux))) {
if (aux.a_type == AT_HWCAP) {
flags = aux.a_val;
readAuxv = true;
break;
}
}
close(fd);
}
if (!readAuxv) {
// Read the cpuinfo Features if the auxv is not available.
FILE* fp = fopen("/proc/cpuinfo", "r");
if (fp) {
char buf[1024];
memset(buf, 0, sizeof(buf));
size_t len = fread(buf, sizeof(char), sizeof(buf) - 1, fp);
fclose(fp);
buf[len] = '\0';
char* featureList = strstr(buf, "Features");
if (featureList) {
if (char* featuresEnd = strstr(featureList, "\n"))
*featuresEnd = '\0';
flags = ParseARMCpuFeatures(featureList + 8);
}
if (strstr(buf, "ARMv7"))
flags |= HWCAP_ARMv7;
}
}
#endif
// If compiled to use specialized features then these features can be
// assumed to be present otherwise the compiler would fail to run.
#ifdef JS_CODEGEN_ARM_HARDFP
// Compiled to use the hardfp ABI.
flags |= HWCAP_USE_HARDFP_ABI;
#endif
#if defined(__VFP_FP__) && !defined(__SOFTFP__)
// Compiled to use VFP instructions so assume VFP support.
flags |= HWCAP_VFP;
#endif
#if defined(__ARM_ARCH_7__) || defined (__ARM_ARCH_7A__)
// Compiled to use ARMv7 instructions so assume the ARMv7 arch.
flags |= HWCAP_ARMv7;
#endif
#if defined(__APPLE__)
#if defined(__ARM_NEON__)
flags |= HWCAP_NEON;
#endif
#if defined(__ARMVFPV3__)
flags |= HWCAP_VFPv3 | HWCAP_VFPD32
#endif
#endif
#endif // JS_SIMULATOR_ARM
armHwCapFlags = CanonicalizeARMHwCapFlags(flags);
JitSpew(JitSpew_Codegen, "ARM HWCAP: 0x%x\n", armHwCapFlags);
return;
}
uint32_t
GetARMFlags()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags;
}
bool HasMOVWT()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_ARMv7;
}
bool HasLDSTREXBHD()
{
// These are really available from ARMv6K and later, but why bother?
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_ARMv7;
}
bool HasDMBDSBISB()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_ARMv7;
}
bool HasVFPv3()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_VFPv3;
}
bool HasVFP()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_VFP;
}
bool Has32DP()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_VFPD32;
}
bool HasIDIV()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_IDIVA;
}
// This is defined in the header and inlined when not using the simulator.
#ifdef JS_SIMULATOR_ARM
bool UseHardFpABI()
{
MOZ_ASSERT(armHwCapFlags != HWCAP_UNINITIALIZED);
return armHwCapFlags & HWCAP_USE_HARDFP_ABI;
}
#endif
Registers::Code
Registers::FromName(const char* name)
{
// Check for some register aliases first.
if (strcmp(name, "ip") == 0)
return ip;
if (strcmp(name, "r13") == 0)
return r13;
if (strcmp(name, "lr") == 0)
return lr;
if (strcmp(name, "r15") == 0)
return r15;
for (size_t i = 0; i < Total; i++) {
if (strcmp(GetName(i), name) == 0)
return Code(i);
}
return Invalid;
}
FloatRegisters::Code
FloatRegisters::FromName(const char* name)
{
for (size_t i = 0; i < Total; i++) {
if (strcmp(GetName(i), name) == 0)
return Code(i);
}
return Invalid;
}
FloatRegisterSet
VFPRegister::ReduceSetForPush(const FloatRegisterSet& s)
{
LiveFloatRegisterSet mod;
for (FloatRegisterIterator iter(s); iter.more(); iter++) {
if ((*iter).isSingle()) {
// Add in just this float.
mod.addUnchecked(*iter);
} else if ((*iter).id() < 16) {
// A double with an overlay, add in both floats.
mod.addUnchecked((*iter).singleOverlay(0));
mod.addUnchecked((*iter).singleOverlay(1));
} else {
// Add in the lone double in the range 16-31.
mod.addUnchecked(*iter);
}
}
return mod.set();
}
uint32_t
VFPRegister::GetPushSizeInBytes(const FloatRegisterSet& s)
{
FloatRegisterSet ss = s.reduceSetForPush();
uint64_t bits = ss.bits();
uint32_t ret = mozilla::CountPopulation32(bits&0xffffffff) * sizeof(float);
ret += mozilla::CountPopulation32(bits >> 32) * sizeof(double);
return ret;
}
uint32_t
VFPRegister::getRegisterDumpOffsetInBytes()
{
if (isSingle())
return id() * sizeof(float);
if (isDouble())
return id() * sizeof(double);
MOZ_CRASH("not Single or Double");
}
uint32_t
FloatRegisters::ActualTotalPhys()
{
if (Has32DP())
return 32;
return 16;
}
} // namespace jit
} // namespace js