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[Bug target/17381] Unnecessary register move for float extend
- From: "pinskia at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 5 Jan 2011 00:15:52 +0000
- Subject: [Bug target/17381] Unnecessary register move for float extend
- Auto-submitted: auto-generated
- References: <bug-17381-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17381
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-01-05 00:15:50 UTC ---
(In reply to comment #5)
> This is the patch which fixes the issue:Index: regrename.c
> ===================================================================
> --- regrename.c (revision 3023)
> +++ regrename.c (working copy)
> @@ -1374,6 +1374,10 @@ maybe_mode_change (enum machine_mode ori
> enum machine_mode new_mode, unsigned int regno,
> unsigned int copy_regno ATTRIBUTE_UNUSED)
> {
> + if (GET_MODE_SIZE (copy_mode) == GET_MODE_SIZE (new_mode)
> + && hard_regno_nregs[copy_regno][copy_mode] ==
> hard_regno_nregs[copy_regno][new_mode]
> + && hard_regno_nregs[regno][copy_mode] ==
> hard_regno_nregs[copy_regno][new_mode])
> + return gen_rtx_raw_REG (new_mode, regno);
> if (orig_mode == new_mode)
> return gen_rtx_raw_REG (new_mode, regno);
> else if (mode_change_ok (orig_mode, new_mode, regno))
MIPS64 has a similar issue too, take:
long long d;
int test1(int fParm)
{
d = fParm + 1;
return fParm + 1;
}
The same regrename.c patch is needed to fix the MIPS64 issue too.