1// -*- C++ -*- 2//===----------------------------------------------------------------------===// 3// 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5// See https://llvm.org/LICENSE.txt for license information. 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7// 8//===----------------------------------------------------------------------===// 9 10#ifndef _LIBCPP___SUPPORT_IBM_GETTOD_ZOS_H 11#define _LIBCPP___SUPPORT_IBM_GETTOD_ZOS_H 12 13#include <time.h> 14 15inline _LIBCPP_HIDE_FROM_ABI int 16gettimeofdayMonotonic(struct timespec64* Output) { 17 18 // The POSIX gettimeofday() function is not available on z/OS. Therefore, 19 // we will call stcke and other hardware instructions in implement equivalent. 20 // Note that nanoseconds alone will overflow when reaching new epoch in 2042. 21 22 struct _t { 23 uint64_t Hi; 24 uint64_t Lo; 25 }; 26 struct _t Value = {0, 0}; 27 uint64_t CC = 0; 28 asm(" stcke %0\n" 29 " ipm %1\n" 30 " srlg %1,%1,28\n" 31 : "=m"(Value), "+r"(CC)::); 32 33 if (CC != 0) { 34 errno = EMVSTODNOTSET; 35 return CC; 36 } 37 uint64_t us = (Value.Hi >> 4); 38 uint64_t ns = ((Value.Hi & 0x0F) << 8) + (Value.Lo >> 56); 39 ns = (ns * 1000) >> 12; 40 us = us - 2208988800000000; 41 42 register uint64_t DivPair0 asm("r0"); // dividend (upper half), remainder 43 DivPair0 = 0; 44 register uint64_t DivPair1 asm("r1"); // dividend (lower half), quotient 45 DivPair1 = us; 46 uint64_t Divisor = 1000000; 47 asm(" dlgr %0,%2" : "+r"(DivPair0), "+r"(DivPair1) : "r"(Divisor) :); 48 49 Output->tv_sec = DivPair1; 50 Output->tv_nsec = DivPair0 * 1000 + ns; 51 return 0; 52} 53 54#endif // _LIBCPP___SUPPORT_IBM_GETTOD_ZOS_H 55