http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59739
Bug ID: 59739
Summary: missed optimization: attribute ((pure)) could be
honored more often
Product: gcc
Version: 4.8.2
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: joerg.rich...@pdv-fs.de
Created attachment 31786
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31786&action=edit
Script for demonstration
Attached is a script (t.sh) that creates two .cc files, compiles and executes
them.
It tests whether attribute ((pure)) is used on different functions with this
signatures:
struct Struct { int val; };
int globalInt();
Struct globalStruct();
struct Class {
int classInt();
Struct classStruct();
virtual int classVirtualInt();
virtual Struct classVirtualStruct();
};
The output with GCC is 4.8.2 is this:
globalInt: 1
globalStruct: 0
classInt: 1
classStruct: 0
classVirtualInt: 0
classVirtualStruct: 0
Meaning only globalInt and classInt are optimised.
All other functions are also candidates for attribute-pure optimisation.
