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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___SUPPORT_IBM_GETTOD_ZOS_H
#define _LIBCPP___SUPPORT_IBM_GETTOD_ZOS_H
#include <time.h>
inline _LIBCPP_HIDE_FROM_ABI int gettimeofdayMonotonic(struct timespec64* Output) {
// The POSIX gettimeofday() function is not available on z/OS. Therefore,
// we will call stcke and other hardware instructions in implement equivalent.
// Note that nanoseconds alone will overflow when reaching new epoch in 2042.
struct _t {
uint64_t Hi;
uint64_t Lo;
};
struct _t Value = {0, 0};
uint64_t CC = 0;
asm(" stcke %0\n"
" ipm %1\n"
" srlg %1,%1,28\n"
: "=m"(Value), "+r"(CC)::);
if (CC != 0) {
errno = EMVSTODNOTSET;
return CC;
}
uint64_t us = (Value.Hi >> 4);
uint64_t ns = ((Value.Hi & 0x0F) << 8) + (Value.Lo >> 56);
ns = (ns * 1000) >> 12;
us = us - 2208988800000000;
register uint64_t DivPair0 asm("r0"); // dividend (upper half), remainder
DivPair0 = 0;
register uint64_t DivPair1 asm("r1"); // dividend (lower half), quotient
DivPair1 = us;
uint64_t Divisor = 1000000;
asm(" dlgr %0,%2" : "+r"(DivPair0), "+r"(DivPair1) : "r"(Divisor) :);
Output->tv_sec = DivPair1;
Output->tv_nsec = DivPair0 * 1000 + ns;
return 0;
}
#endif // _LIBCPP___SUPPORT_IBM_GETTOD_ZOS_H
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