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* [Bug c++/26116] New: Optimizer regression from v3 to v4
@ 2006-02-06 8:01 gianni at mariani dot ws
2006-02-06 10:34 ` [Bug c++/26116] " rguenth at gcc dot gnu dot org
0 siblings, 1 reply; 2+ messages in thread
From: gianni at mariani dot ws @ 2006-02-06 8:01 UTC (permalink / raw)
To: gcc-bugs
Prior to the 4.* series compilers, the following code :
char tell_endian()
{
unsigned x = 1;
return *(char*)&x;
}
... used to produce a simple contant load to a register and return. The 4.x
compilers seem like they can no longer make this optimization. It used to be
very convenient because code written using this construct would automatically
eliminate code since it was correctly able to identify that the return value
from "tell_endian" is a constant, i.e.
if ( tell_endian() ) little_stuff() else big_stuff()
would generate code consistant with simply writing "little_stuff()" on little
endian systems (and visa versa).
--
Summary: Optimizer regression from v3 to v4
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: gianni at mariani dot ws
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26116
^ permalink raw reply [flat|nested] 2+ messages in thread
* [Bug c++/26116] Optimizer regression from v3 to v4
2006-02-06 8:01 [Bug c++/26116] New: Optimizer regression from v3 to v4 gianni at mariani dot ws
@ 2006-02-06 10:34 ` rguenth at gcc dot gnu dot org
0 siblings, 0 replies; 2+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-02-06 10:34 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from rguenth at gcc dot gnu dot org 2006-02-06 10:34 -------
*** This bug has been marked as a duplicate of 26069 ***
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26116
^ permalink raw reply [flat|nested] 2+ messages in thread
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2006-02-06 8:01 [Bug c++/26116] New: Optimizer regression from v3 to v4 gianni at mariani dot ws
2006-02-06 10:34 ` [Bug c++/26116] " rguenth at gcc dot gnu dot org
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