From 84098e25fabc160c0178602082dcfbe547f5bc8d Mon Sep 17 00:00:00 2001 From: singler Date: Tue, 8 Jun 2010 09:11:49 +0000 Subject: [PATCH] 2010-06-08 Johannes Singler * include/parallel/partial_sum.h (__parallel_partial_sum_linear): Correctly calculate part lengths for partial_sum_dilation!=1.0f. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@160428 138bc75d-0d04-0410-961f-82ee72b054a4 --- libstdc++-v3/ChangeLog | 6 ++++++ libstdc++-v3/include/parallel/partial_sum.h | 9 ++++++--- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 0f24ab4..3ebfd13 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,9 @@ +2010-06-08 Johannes Singler + + * include/parallel/partial_sum.h + (__parallel_partial_sum_linear): + Correctly calculate part lengths for partial_sum_dilation!=1. + 2010-06-07 Paolo Carlini PR libstdc++/44417 diff --git a/libstdc++-v3/include/parallel/partial_sum.h b/libstdc++-v3/include/parallel/partial_sum.h index 966d9db..d398c45 100644 --- a/libstdc++-v3/include/parallel/partial_sum.h +++ b/libstdc++-v3/include/parallel/partial_sum.h @@ -127,10 +127,13 @@ namespace __gnu_parallel equally_split(__n, __num_threads + 1, __borders); else { + _DifferenceType __first_part_length = + std::max<_DifferenceType>(1, + __n / (1.0f + __s.partial_sum_dilation * __num_threads)); _DifferenceType __chunk_length = - ((double)__n - / ((double)__num_threads + __s.partial_sum_dilation)), - __borderstart = __n - __num_threads * __chunk_length; + (__n - __first_part_length) / __num_threads; + _DifferenceType __borderstart = + __n - __num_threads * __chunk_length; __borders[0] = 0; for (_ThreadIndex __i = 1; __i < (__num_threads + 1); ++__i) { -- 2.7.4