I use std::inner_product() to do the vector multiplication when performing
matrix multiplication. This involves calling std::inner_product() within 2
nested loops (one across all rows, one across all columns). Unfortunately,
g++-4.1.2 will not, it seems, inline the call even at -O5. If I provide my own
version with an inline hint, it improves the speed of my matrix multiplication
by ~15%, which is not to be sniffed at.
I suppose my questions would be:
(a) erm, do you need proof?
(b) should the compiler do the inlining regardless (ie, it's a compiler issue),
or should the declaration of std::inner_product give a hint with the inline
keyword (and perhaps also other functions)?
Simon.
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Summary: inlining std::inner_product()
Product: gcc
Version: 4.2.1
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: simon dot marshall at misys dot com
GCC host triplet: sparc-sun-solaris2.8
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33293
