Commit d9b84c2c authored by Vadim Paretsky's avatar Vadim Paretsky
Browse files

[OpenMP] remove usage of std::abs in the new loop collapse support code 

On some platforms, std::abs may inadvertently pull in a math library.
This patch replaces its use in the new loop collapse code with
a no thrills in-situ implementation.

Differential Revision: https://reviews.llvm.org/D150882
parent 3b78065e

openmp/runtime/src/kmp_collapse.cpp

+16 −11
Original line number Diff line number Diff line
@@ -18,8 +18,6 @@ 
#include "kmp_str.h"

#include "kmp_collapse.h"



#include <cmath>



#if OMPT_SUPPORT

#include "ompt-specific.h"

#endif
@@ -27,11 +25,18 @@ 
// OMPTODO: different style of comments (see kmp_sched)

// OMPTODO: OMPT/OMPD



// avoid inadevertently using a library based abs

template <typename T> T __kmp_abs(const T val) {

  return (val < 0) ? -val: val;

}

kmp_uint32 __kmp_abs(const kmp_uint32 val) { return val; }

kmp_uint64 __kmp_abs(const kmp_uint64 val) { return val; }



//----------------------------------------------------------------------------

// Common functions for working with rectangular and non-rectangular loops

//----------------------------------------------------------------------------



template <typename T> int sign(T val) { return (T(0) < val) - (val < T(0)); }

template <typename T> int __kmp_sign(T val) { return (T(0) < val) - (val < T(0)); }



//----------Loop canonicalization---------------------------------------------
@@ -131,7 +136,7 @@ kmp_loop_nest_iv_t kmp_calculate_trip_count_XX( 
      // kmp_loop_nest_iv_t anyway

      bounds->trip_count =

          static_cast<kmp_loop_nest_iv_t>(bounds->ub0 - bounds->lb0) /

              std::abs(bounds->step) +

              __kmp_abs(bounds->step) +

          1;

    }

  } else if (bounds->comparison == comparison_t::comp_greater_or_eq) {
@@ -144,7 +149,7 @@ kmp_loop_nest_iv_t kmp_calculate_trip_count_XX( 
      // kmp_loop_nest_iv_t anyway

      bounds->trip_count =

          static_cast<kmp_loop_nest_iv_t>(bounds->lb0 - bounds->ub0) /

              std::abs(bounds->step) +

              __kmp_abs(bounds->step) +

          1;

    }

  } else {
@@ -658,16 +663,16 @@ void kmp_calc_new_bounds_XX( 
    T old_lb1 = bbounds.lb1;

    T old_ub1 = bbounds.ub1;



    if (sign(old_lb1) != sign(old_ub1)) {

    if (__kmp_sign(old_lb1) != __kmp_sign(old_ub1)) {

      // With this shape we can adjust to a rectangle:

      bbounds.lb1 = 0;

      bbounds.ub1 = 0;

    } else {

      // get upper and lower bounds to be parallel

      // with values in the old range.

      // Note: std::abs didn't work here.

      if (((sign(old_lb1) == -1) && (old_lb1 < old_ub1)) ||

          ((sign(old_lb1) == 1) && (old_lb1 > old_ub1))) {

      // Note: abs didn't work here.

      if (((old_lb1 < 0) && (old_lb1 < old_ub1)) ||

          ((old_lb1 > 0) && (old_lb1 > old_ub1))) {

        bbounds.lb1 = old_ub1;

      } else {

        bbounds.ub1 = old_lb1;
@@ -804,13 +809,13 @@ kmp_calc_number_of_iterations_XX(const bounds_infoXX_template<T> *bounds, 
    iterations =

        (static_cast<T>(original_ivs[ind]) - bounds->lb0 -

         bounds->lb1 * static_cast<T>(original_ivs[bounds->outer_iv])) /

        std::abs(bounds->step);

        __kmp_abs(bounds->step);

  } else {

    KMP_DEBUG_ASSERT(bounds->comparison == comparison_t::comp_greater_or_eq);

    iterations = (bounds->lb0 +

                  bounds->lb1 * static_cast<T>(original_ivs[bounds->outer_iv]) -

                  static_cast<T>(original_ivs[ind])) /

                 std::abs(bounds->step);

                 __kmp_abs(bounds->step);

  }



  return iterations;