[flang-commits] [flang] [llvm] [flang][flang-rt] Add support for non-standard TIMEF intrinsic (PR #185377)

[Eugene Epshteyn via flang-commits]

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@@ -413,6 +413,18 @@ double RTNAME(Dsecnds)(double *refTime, const char *sourceFile, int line) {
 // GNU extension function TIME()
 std::int64_t RTNAME(time)() { return time(nullptr); }
 
+// Intel extension function TIMEF()
+// Returns number of seconds that have elapsed since the first time
+// TIMEF was called. For the first call, it returns 0.
+double RTNAME(Timef)() {
+  static double first = -1;
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eugeneepshteyn wrote:

`thread_local` could work, please try it.

Here's the parallel tests I wrote for `secnds()` intrinsic, you can adapt it to test multithreaded `timef()`:
```
use omp_lib
real sec_mid
real results(1000)
integer i, num_threads

results = 0.0
!$omp parallel do
do i=1, size(results)
  results(i) = secnds(0.0)
  num_threads = omp_get_num_threads()
end do
!$omp end parallel do

print *, "Number of threads in parallel region:", num_threads

sec_mid = minval(results)
print *, "Seconds from midnight: min:", sec_mid, ", max:", maxval(results) 

call sleep(2)

!$omp parallel do
do i=1, size(results)
  results(i) = secnds(sec_mid)
end do
!$omp end parallel do

print *, "Seconds from sec_mid: min:", minval(results), ", max:", maxval(results)
print *, "Seconds from midnight:", secnds(0.0)
end
```

https://github.com/llvm/llvm-project/pull/185377