Bug 78401 - SciMark v2.0 Composite test runs 1,5 times slower under GCC 6.2 than under Clang 3.9
Summary: SciMark v2.0 Composite test runs 1,5 times slower under GCC 6.2 than under Cl...
Status: RESOLVED INVALID
Alias: None
Product: gcc
Classification: Unclassified
Component: middle-end (show other bugs)
Version: 6.2.0
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks: 79703
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Reported: 2016-11-17 16:48 UTC by Artem S. Tashkinov
Modified: 2017-07-26 07:24 UTC (History)
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Description Artem S. Tashkinov 2016-11-17 16:48:37 UTC 
As per http://www.phoronix.com/scan.php?page=article&item=gcc-clang-kblclear&num=2

GCC 6.2.0 - 1057
Clang 3.9.0 - 1603

g++ options: -O3 -march=native

CPU: Kaby Lake 7200U (the same CPU core as Sandy Bridge)
Comment 1 Uroš Bizjak 2017-02-24 10:30:02 UTC 
Can you please provide perf report of hot spots?
Comment 2 Uroš Bizjak 2017-07-26 07:24:46 UTC 
Phoronix Scimark 2.0 tests were faulty [1].

[1] https://kristerw.blogspot.si/2017/07/phoronix-scimark-benchmarking-results.html