//===-- runtime/time-intrinsic.cpp ----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Implements time-related intrinsic subroutines.
#include "flang/Runtime/time-intrinsic.h"
#include "terminator.h"
#include "tools.h"
#include "flang/Runtime/cpp-type.h"
#include "flang/Runtime/descriptor.h"
#include <algorithm>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#ifdef _WIN32
#include "flang/Common/windows-include.h"
#else
#include <sys/time.h> // gettimeofday
#include <sys/times.h>
#include <unistd.h>
#endif
// CPU_TIME (Fortran 2018 16.9.57)
// SYSTEM_CLOCK (Fortran 2018 16.9.168)
//
// We can use std::clock() from the <ctime> header as a fallback implementation
// that should be available everywhere. This may not provide the best resolution
// and is particularly troublesome on (some?) POSIX systems where CLOCKS_PER_SEC
// is defined as 10^6 regardless of the actual precision of std::clock().
// Therefore, we will usually prefer platform-specific alternatives when they
// are available.
//
// We can use SFINAE to choose a platform-specific alternative. To do so, we
// introduce a helper function template, whose overload set will contain only
// implementations relying on interfaces which are actually available. Each
// overload will have a dummy parameter whose type indicates whether or not it
// should be preferred. Any other parameters required for SFINAE should have
// default values provided.
namespace {
// Types for the dummy parameter indicating the priority of a given overload.
// We will invoke our helper with an integer literal argument, so the overload
// with the highest priority should have the type int.
using fallback_implementation = double;
using preferred_implementation = int;
// This is the fallback implementation, which should work everywhere.
template <typename Unused = void> double GetCpuTime(fallback_implementation) {
std::clock_t timestamp{std::clock()};
if (timestamp != static_cast<std::clock_t>(-1)) {
return static_cast<double>(timestamp) / CLOCKS_PER_SEC;
}
// Return some negative value to represent failure.
return -1.0;
}
#if defined __MINGW32__
// clock_gettime is implemented in the pthread library for MinGW.
// Using it here would mean that all programs that link libFortranRuntime are
// required to also link to pthread. Instead, don't use the function.
#undef CLOCKID_CPU_TIME
#undef CLOCKID_ELAPSED_TIME
#else
// Determine what clock to use for CPU time.
#if defined CLOCK_PROCESS_CPUTIME_ID
#define CLOCKID_CPU_TIME CLOCK_PROCESS_CPUTIME_ID
#elif defined CLOCK_THREAD_CPUTIME_ID
#define CLOCKID_CPU_TIME CLOCK_THREAD_CPUTIME_ID
#else
#undef CLOCKID_CPU_TIME
#endif
// Determine what clock to use for elapsed time.
#if defined CLOCK_MONOTONIC
#define CLOCKID_ELAPSED_TIME CLOCK_MONOTONIC
#elif defined CLOCK_REALTIME
#define CLOCKID_ELAPSED_TIME CLOCK_REALTIME
#else
#undef CLOCKID_ELAPSED_TIME
#endif
#endif
#ifdef CLOCKID_CPU_TIME
// POSIX implementation using clock_gettime. This is only enabled where
// clock_gettime is available.
template <typename T = int, typename U = struct timespec>
double GetCpuTime(preferred_implementation,
// We need some dummy parameters to pass to decltype(clock_gettime).
T ClockId = 0, U *Timespec = nullptr,
decltype(clock_gettime(ClockId, Timespec)) *Enabled = nullptr) {
struct timespec tspec;
if (clock_gettime(CLOCKID_CPU_TIME, &tspec) == 0) {
return tspec.tv_nsec * 1.0e-9 + tspec.tv_sec;
}
// Return some negative value to represent failure.
return -1.0;
}
#endif // CLOCKID_CPU_TIME
using count_t = std::int64_t;
using unsigned_count_t = std::uint64_t;
// POSIX implementation using clock_gettime where available. The clock_gettime
// result is in nanoseconds, which is converted as necessary to
// - deciseconds for kind 1
// - milliseconds for kinds 2, 4
// - nanoseconds for kinds 8, 16
constexpr unsigned_count_t DS_PER_SEC{10u};
constexpr unsigned_count_t MS_PER_SEC{1'000u};
constexpr unsigned_count_t NS_PER_SEC{1'000'000'000u};
// Computes HUGE(INT(0,kind)) as an unsigned integer value.
static constexpr inline unsigned_count_t GetHUGE(int kind) {
if (kind > 8) {
kind = 8;
}
return (unsigned_count_t{1} << ((8 * kind) - 1)) - 1;
}
// Function converts a std::timespec_t into the desired count to
// be returned by the timing functions in accordance with the requested
// kind at the call site.
count_t ConvertTimeSpecToCount(int kind, const struct timespec &tspec) {
const unsigned_count_t huge{GetHUGE(kind)};
unsigned_count_t sec{static_cast<unsigned_count_t>(tspec.tv_sec)};
unsigned_count_t nsec{static_cast<unsigned_count_t>(tspec.tv_nsec)};
if (kind >= 8) {
return (sec * NS_PER_SEC + nsec) % (huge + 1);
} else if (kind >= 2) {
return (sec * MS_PER_SEC + (nsec / (NS_PER_SEC / MS_PER_SEC))) % (huge + 1);
} else { // kind == 1
return (sec * DS_PER_SEC + (nsec / (NS_PER_SEC / DS_PER_SEC))) % (huge + 1);
}
}
#ifndef _AIX
// This is the fallback implementation, which should work everywhere.
template <typename Unused = void>
count_t GetSystemClockCount(int kind, fallback_implementation) {
struct timespec tspec;
if (timespec_get(&tspec, TIME_UTC) < 0) {
// Return -HUGE(COUNT) to represent failure.
return -static_cast<count_t>(GetHUGE(kind));
}
// Compute the timestamp as seconds plus nanoseconds in accordance
// with the requested kind at the call site.
return ConvertTimeSpecToCount(kind, tspec);
}
#endif
template <typename Unused = void>
count_t GetSystemClockCountRate(int kind, fallback_implementation) {
return kind >= 8 ? NS_PER_SEC : kind >= 2 ? MS_PER_SEC : DS_PER_SEC;
}
template <typename Unused = void>
count_t GetSystemClockCountMax(int kind, fallback_implementation) {
unsigned_count_t maxCount{GetHUGE(kind)};
return maxCount;
}
#ifdef CLOCKID_ELAPSED_TIME
template <typename T = int, typename U = struct timespec>
count_t GetSystemClockCount(int kind, preferred_implementation,
// We need some dummy parameters to pass to decltype(clock_gettime).
T ClockId = 0, U *Timespec = nullptr,
decltype(clock_gettime(ClockId, Timespec)) *Enabled = nullptr) {
struct timespec tspec;
const unsigned_count_t huge{GetHUGE(kind)};
if (clock_gettime(CLOCKID_ELAPSED_TIME, &tspec) != 0) {
return -huge; // failure
}
// Compute the timestamp as seconds plus nanoseconds in accordance
// with the requested kind at the call site.
return ConvertTimeSpecToCount(kind, tspec);
}
#endif // CLOCKID_ELAPSED_TIME
template <typename T = int, typename U = struct timespec>
count_t GetSystemClockCountRate(int kind, preferred_implementation,
// We need some dummy parameters to pass to decltype(clock_gettime).
T ClockId = 0, U *Timespec = nullptr,
decltype(clock_gettime(ClockId, Timespec)) *Enabled = nullptr) {
return kind >= 8 ? NS_PER_SEC : kind >= 2 ? MS_PER_SEC : DS_PER_SEC;
}
template <typename T = int, typename U = struct timespec>
count_t GetSystemClockCountMax(int kind, preferred_implementation,
// We need some dummy parameters to pass to decltype(clock_gettime).
T ClockId = 0, U *Timespec = nullptr,
decltype(clock_gettime(ClockId, Timespec)) *Enabled = nullptr) {
return GetHUGE(kind);
}
// DATE_AND_TIME (Fortran 2018 16.9.59)
// Helper to set an integer value to -HUGE
template <int KIND> struct StoreNegativeHugeAt {
void operator()(
const Fortran::runtime::Descriptor &result, std::size_t at) const {
*result.ZeroBasedIndexedElement<Fortran::runtime::CppTypeFor<
Fortran::common::TypeCategory::Integer, KIND>>(at) =
-std::numeric_limits<Fortran::runtime::CppTypeFor<
Fortran::common::TypeCategory::Integer, KIND>>::max();
}
};
// Default implementation when date and time information is not available (set
// strings to blanks and values to -HUGE as defined by the standard).
static void DateAndTimeUnavailable(Fortran::runtime::Terminator &terminator,
char *date, std::size_t dateChars, char *time, std::size_t timeChars,
char *zone, std::size_t zoneChars,
const Fortran::runtime::Descriptor *values) {
if (date) {
std::memset(date, static_cast<int>(' '), dateChars);
}
if (time) {
std::memset(time, static_cast<int>(' '), timeChars);
}
if (zone) {
std::memset(zone, static_cast<int>(' '), zoneChars);
}
if (values) {
auto typeCode{values->type().GetCategoryAndKind()};
RUNTIME_CHECK(terminator,
values->rank() == 1 && values->GetDimension(0).Extent() >= 8 &&
typeCode &&
typeCode->first == Fortran::common::TypeCategory::Integer);
// DATE_AND_TIME values argument must have decimal range > 4. Do not accept
// KIND 1 here.
int kind{typeCode->second};
RUNTIME_CHECK(terminator, kind != 1);
for (std::size_t i = 0; i < 8; ++i) {
Fortran::runtime::ApplyIntegerKind<StoreNegativeHugeAt, void>(
kind, terminator, *values, i);
}
}
}
#ifndef _WIN32
#ifdef _AIX
// Compute the time difference from GMT/UTC to get around the behavior of
// strfname on AIX that requires setting an environment variable for numeric
// value for ZONE.
// The ZONE and the VALUES(4) arguments of the DATE_AND_TIME intrinsic has
// the resolution to the minute.
static int computeUTCDiff(const tm &localTime, bool *err) {
tm utcTime;
const time_t timer{mktime(const_cast<tm *>(&localTime))};
if (timer < 0) {
*err = true;
return 0;
}
// Get the GMT/UTC time
if (gmtime_r(&timer, &utcTime) == nullptr) {
*err = true;
return 0;
}
// Adjust for day difference
auto dayDiff{localTime.tm_mday - utcTime.tm_mday};
auto localHr{localTime.tm_hour};
if (dayDiff > 0) {
if (dayDiff == 1) {
localHr += 24;
} else {
utcTime.tm_hour += 24;
}
} else if (dayDiff < 0) {
if (dayDiff == -1) {
utcTime.tm_hour += 24;
} else {
localHr += 24;
}
}
return (localHr * 60 + localTime.tm_min) -
(utcTime.tm_hour * 60 + utcTime.tm_min);
}
#endif
static std::size_t getUTCOffsetToBuffer(
char *buffer, const std::size_t &buffSize, tm *localTime) {
#ifdef _AIX
// format: +HHMM or -HHMM
bool err{false};
auto utcOffset{computeUTCDiff(*localTime, &err)};
auto hour{utcOffset / 60};
auto hrMin{hour * 100 + (utcOffset - hour * 60)};
auto n{sprintf(buffer, "%+05d", hrMin)};
return err ? 0 : n + 1;
#else
return std::strftime(buffer, buffSize, "%z", localTime);
#endif
}
// SFINAE helper to return the struct tm.tm_gmtoff which is not a POSIX standard
// field.
template <int KIND, typename TM = struct tm>
Fortran::runtime::CppTypeFor<Fortran::common::TypeCategory::Integer, KIND>
GetGmtOffset(const TM &tm, preferred_implementation,
decltype(tm.tm_gmtoff) *Enabled = nullptr) {
// Returns the GMT offset in minutes.
return tm.tm_gmtoff / 60;
}
template <int KIND, typename TM = struct tm>
Fortran::runtime::CppTypeFor<Fortran::common::TypeCategory::Integer, KIND>
GetGmtOffset(const TM &tm, fallback_implementation) {
// tm.tm_gmtoff is not available, there may be platform dependent alternatives
// (such as using timezone from <time.h> when available), but so far just
// return -HUGE to report that this information is not available.
const auto negHuge{-std::numeric_limits<Fortran::runtime::CppTypeFor<
Fortran::common::TypeCategory::Integer, KIND>>::max()};
#ifdef _AIX
bool err{false};
auto diff{computeUTCDiff(tm, &err)};
if (err) {
return negHuge;
} else {
return diff;
}
#else
return negHuge;
#endif
}
template <typename TM = struct tm> struct GmtOffsetHelper {
template <int KIND> struct StoreGmtOffset {
void operator()(const Fortran::runtime::Descriptor &result, std::size_t at,
TM &tm) const {
*result.ZeroBasedIndexedElement<Fortran::runtime::CppTypeFor<
Fortran::common::TypeCategory::Integer, KIND>>(at) =
GetGmtOffset<KIND>(tm, 0);
}
};
};
// Dispatch to posix implementation where gettimeofday and localtime_r are
// available.
static void GetDateAndTime(Fortran::runtime::Terminator &terminator, char *date,
std::size_t dateChars, char *time, std::size_t timeChars, char *zone,
std::size_t zoneChars, const Fortran::runtime::Descriptor *values) {
timeval t;
if (gettimeofday(&t, nullptr) != 0) {
DateAndTimeUnavailable(
terminator, date, dateChars, time, timeChars, zone, zoneChars, values);
return;
}
time_t timer{t.tv_sec};
tm localTime;
localtime_r(&timer, &localTime);
std::intmax_t ms{t.tv_usec / 1000};
static constexpr std::size_t buffSize{16};
char buffer[buffSize];
auto copyBufferAndPad{
[&](char *dest, std::size_t destChars, std::size_t len) {
auto copyLen{std::min(len, destChars)};
std::memcpy(dest, buffer, copyLen);
for (auto i{copyLen}; i < destChars; ++i) {
dest[i] = ' ';
}
}};
if (date) {
auto len = std::strftime(buffer, buffSize, "%Y%m%d", &localTime);
copyBufferAndPad(date, dateChars, len);
}
if (time) {
auto len{std::snprintf(buffer, buffSize, "%02d%02d%02d.%03jd",
localTime.tm_hour, localTime.tm_min, localTime.tm_sec, ms)};
copyBufferAndPad(time, timeChars, len);
}
if (zone) {
// Note: this may leave the buffer empty on many platforms. Classic flang
// has a much more complex way of doing this (see __io_timezone in classic
// flang).
auto len{getUTCOffsetToBuffer(buffer, buffSize, &localTime)};
copyBufferAndPad(zone, zoneChars, len);
}
if (values) {
auto typeCode{values->type().GetCategoryAndKind()};
RUNTIME_CHECK(terminator,
values->rank() == 1 && values->GetDimension(0).Extent() >= 8 &&
typeCode &&
typeCode->first == Fortran::common::TypeCategory::Integer);
// DATE_AND_TIME values argument must have decimal range > 4. Do not accept
// KIND 1 here.
int kind{typeCode->second};
RUNTIME_CHECK(terminator, kind != 1);
auto storeIntegerAt = [&](std::size_t atIndex, std::int64_t value) {
Fortran::runtime::ApplyIntegerKind<Fortran::runtime::StoreIntegerAt,
void>(kind, terminator, *values, atIndex, value);
};
storeIntegerAt(0, localTime.tm_year + 1900);
storeIntegerAt(1, localTime.tm_mon + 1);
storeIntegerAt(2, localTime.tm_mday);
Fortran::runtime::ApplyIntegerKind<
GmtOffsetHelper<struct tm>::StoreGmtOffset, void>(
kind, terminator, *values, 3, localTime);
storeIntegerAt(4, localTime.tm_hour);
storeIntegerAt(5, localTime.tm_min);
storeIntegerAt(6, localTime.tm_sec);
storeIntegerAt(7, ms);
}
}
#else
// Fallback implementation where gettimeofday or localtime_r are not both
// available (e.g. windows).
static void GetDateAndTime(Fortran::runtime::Terminator &terminator, char *date,
std::size_t dateChars, char *time, std::size_t timeChars, char *zone,
std::size_t zoneChars, const Fortran::runtime::Descriptor *values) {
// TODO: An actual implementation for non Posix system should be added.
// So far, implement as if the date and time is not available on those
// platforms.
DateAndTimeUnavailable(
terminator, date, dateChars, time, timeChars, zone, zoneChars, values);
}
#endif
} // namespace
namespace Fortran::runtime {
extern "C" {
double RTNAME(CpuTime)() { return GetCpuTime(0); }
std::int64_t RTNAME(SystemClockCount)(int kind) {
return GetSystemClockCount(kind, 0);
}
std::int64_t RTNAME(SystemClockCountRate)(int kind) {
return GetSystemClockCountRate(kind, 0);
}
std::int64_t RTNAME(SystemClockCountMax)(int kind) {
return GetSystemClockCountMax(kind, 0);
}
void RTNAME(DateAndTime)(char *date, std::size_t dateChars, char *time,
std::size_t timeChars, char *zone, std::size_t zoneChars,
const char *source, int line, const Descriptor *values) {
Fortran::runtime::Terminator terminator{source, line};
return GetDateAndTime(
terminator, date, dateChars, time, timeChars, zone, zoneChars, values);
}
void RTNAME(Etime)(const Descriptor *values, const Descriptor *time,
const char *sourceFile, int line) {
Fortran::runtime::Terminator terminator{sourceFile, line};
double usrTime = -1.0, sysTime = -1.0, realTime = -1.0;
#ifdef _WIN32
FILETIME creationTime;
FILETIME exitTime;
FILETIME kernelTime;
FILETIME userTime;
if (GetProcessTimes(GetCurrentProcess(), &creationTime, &exitTime,
&kernelTime, &userTime) == 0) {
ULARGE_INTEGER userSystemTime;
ULARGE_INTEGER kernelSystemTime;
memcpy(&userSystemTime, &userTime, sizeof(FILETIME));
memcpy(&kernelSystemTime, &kernelTime, sizeof(FILETIME));
usrTime = ((double)(userSystemTime.QuadPart)) / 10000000.0;
sysTime = ((double)(kernelSystemTime.QuadPart)) / 10000000.0;
realTime = usrTime + sysTime;
}
#else
struct tms tms;
if (times(&tms) != (clock_t)-1) {
usrTime = ((double)(tms.tms_utime)) / sysconf(_SC_CLK_TCK);
sysTime = ((double)(tms.tms_stime)) / sysconf(_SC_CLK_TCK);
realTime = usrTime + sysTime;
}
#endif
if (values) {
auto typeCode{values->type().GetCategoryAndKind()};
// ETIME values argument must have decimal range == 2.
RUNTIME_CHECK(terminator,
values->rank() == 1 && values->GetDimension(0).Extent() == 2 &&
typeCode && typeCode->first == Fortran::common::TypeCategory::Real);
// Only accept KIND=4 here.
int kind{typeCode->second};
RUNTIME_CHECK(terminator, kind == 4);
ApplyFloatingPointKind<StoreFloatingPointAt, void>(
kind, terminator, *values, /* atIndex = */ 0, usrTime);
ApplyFloatingPointKind<StoreFloatingPointAt, void>(
kind, terminator, *values, /* atIndex = */ 1, sysTime);
}
if (time) {
auto typeCode{time->type().GetCategoryAndKind()};
// ETIME time argument must have decimal range == 0.
RUNTIME_CHECK(terminator,
time->rank() == 0 && typeCode &&
typeCode->first == Fortran::common::TypeCategory::Real);
// Only accept KIND=4 here.
int kind{typeCode->second};
RUNTIME_CHECK(terminator, kind == 4);
ApplyFloatingPointKind<StoreFloatingPointAt, void>(
kind, terminator, *time, /* atIndex = */ 0, realTime);
}
}
} // extern "C"
} // namespace Fortran::runtime
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