This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/66652] try_transform_to_exit_first_loop_alt generates incorrect loop
- From: "vries at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 27 Jun 2015 05:52:41 +0000
- Subject: [Bug tree-optimization/66652] try_transform_to_exit_first_loop_alt generates incorrect loop
- Auto-submitted: auto-generated
- References: <bug-66652-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66652
--- Comment #2 from vries at gcc dot gnu.org ---
Created attachment 35865
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35865&action=edit
follow-up patch for demonstrator patch
This patch in addition allows transform_to_exit_first_loop_alt for unsigned
loop counters. But it's not generic enough to also handle the fortran testcases
in https://gcc.gnu.org/ml/gcc-patches/2015-06/msg01234.html .
For parloops-exit-first-loop-alt.f95, we have:
...
foo (integer(kind=4)D.8 & restrict nrD.3381)
{
integer(kind=4) ii;
integer(kind=4) _6;
integer(kind=4) _7;
integer(kind=8) _8;
integer(kind=4) _9;
integer(kind=4) _10;
integer(kind=4) _11;
integer(kind=4) _12;
integer(kind=4) _13;
integer(kind=8) _16;
unsigned int _19;
integer(kind=4) _20;
integer(kind=4) _22;
integer(kind=4) _23;
integer(kind=4) _24;
signed int ivtmp_27;
signed int ivtmp_28;
<bb 2>:
_6 = *nr_5(D);
_7 = _6 + -1;
if (_7 >= 0)
goto <bb 4>;
else
goto <bb 3>;
<bb 3>:
return;
<bb 4>:
_20 = _6 + -1;
_19 = (unsigned int) _20;
<bb 10>:
if (_19 > 199)
goto <bb 11>;
else
goto <bb 12>;
<bb 11>:
<bb 5>:
# ivtmp_27 = PHI <0(11), ivtmp_28(7)>
ii_1 = ivtmp_27;
_8 = (integer(kind=8)) ii_1;
_9 = __BLNK__.a[_8];
_11 = __BLNK__.b[_8];
_12 = _9 + _11;
_13 = _12 + 25;
__BLNK__.c[_8] = _13;
ii_15 = ii_1 + 1;
if (ivtmp_27 < _19)
goto <bb 7>;
else
goto <bb 6>;
<bb 6>:
goto <bb 3>;
<bb 7>:
ivtmp_28 = ivtmp_27 + 1;
goto <bb 5>;
<bb 12>:
<bb 8>:
# ii_18 = PHI <0(12), ii_26(9)>
_16 = (integer(kind=8)) ii_18;
_10 = __BLNK__.a[_16];
_23 = __BLNK__.b[_16];
_22 = _10 + _23;
_24 = _22 + 25;
__BLNK__.c[_16] = _24;
ii_26 = ii_18 + 1;
if (ii_18 == _7)
goto <bb 6>;
else
goto <bb 9>;
<bb 9>:
goto <bb 8>;
}
...
the nit is _19:
...
_20 = _6 + -1;
_19 = (unsigned int) _20;
...