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[Bug optimization/4079] unnecessary register move on simple code
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 29 Mar 2004 05:32:13 -0000
- Subject: [Bug optimization/4079] unnecessary register move on simple code
- References: <20010822061601.4079.mattias@virtutech.se>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-03-29 05:32 -------
Using unions make the code not use a "mv" instruction:
unsigned mulh(unsigned a, unsigned b)
{
union a{
unsigned long long ull;
unsigned long ul[2];
}ullul;
ullul.ull = ((unsigned long long)a * (unsigned long long)b);
return ullul.ul[1];
}
--
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2003-11-28 07:53:38 |2004-03-29 05:32:12
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=4079