https://llvm.org/bugs/show_bug.cgi?id=23619
Bug ID: 23619
Summary: Performance regression versus GCC 4.9.1 -- test case
and ASM attached
Product: clang
Version: 3.6
Hardware: Macintosh
OS: MacOS X
Status: NEW
Severity: normal
Priority: P
Component: LLVM Codegen
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Classification: Unclassified
Created attachment 14358
--> https://llvm.org/bugs/attachment.cgi?id=14358&action=edit
Compiler-generated ASM
With the attached code, the gcc version is 20% faster than the clang version.
clang++
--------
clang++ --version
Apple LLVM version 6.1.0 (clang-602.0.49) (based on LLVM 3.6.0svn)
Target: x86_64-apple-darwin14.3.0
Thread model: posix
clang++ -std=c++11 -O2 dsp.cpp main.cpp -o dsp && ./dsp
85,758,063 shorts/second
gcc
--------
gcc-mp-4.9 --version
gcc-mp-4.9 (MacPorts gcc49 4.9.2_1) 4.9.2
gcc-mp-4.9 -std=c++11 -O2 dsp.cpp main.cpp -o dsp && ./dsp
102,104,163 shorts/second
Source code: https://gist.github.com/anonymous/fd213a7b8ffdcfd219dc
Compiler-generated ASM attached.
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
LLVMbugs mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/llvmbugs
