From patchwork Tue Jul 24 14:56:41 2012
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Subject: un-#ifdef GATHER_STATISTICS
Date: Tue, 24 Jul 2012 04:56:41 -0000
From: Steven Bosscher <stevenb.gcc@gmail.com>
X-Patchwork-Id: 172894
Message-Id: <CABu31nPcF6uD13Od--N2KyFHDiNxPBYQNMhdj-6ijL=KooT=gg@mail.gmail.com>
To: Uros Bizjak <ubizjak@gmail.com>, Andrey Belevantsev <abel@ispras.ru>,
 "H.J. Lu" <hjl.tools@gmail.com>
Cc: gcc-patches@gcc.gnu.org, Richard Guenther <richard.guenther@gmail.com>

On Tue, Jul 24, 2012 at 4:37 PM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> On Tue, Jul 24, 2012 at 3:08 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> This patch (r189803) regressed a bunch of tests on x86_64 [1], [2].
>>
>> [1] http://gcc.gnu.org/ml/gcc-testresults/2012-07/msg02066.html
>> [2] http://gcc.gnu.org/ml/gcc-regression/2012-07/msg00177.html
>
> These are all selective-scheduler test cases. It looks like qsort is
> being used incorrectly.

This seems to fix it for me, but I don't understand why. Apparently, a
pointer subtraction doesn't result in a signed value?? In any case,
the sort on those arrays wasn't correct. Comments?


Index: sel-sched-ir.c
===================================================================
--- sel-sched-ir.c      (revision 189808)
+++ sel-sched-ir.c      (working copy)
@@ -954,7 +954,9 @@ return_regset_to_pool (regset rs)
 static int
 cmp_v_in_regset_pool (const void *x, const void *xx)
 {
-  return *((const regset *) x) - *((const regset *) xx);
+  ptrdiff_t d = (ptrdiff_t) *((const regset *) x);
+  ptrdiff_t dd = (ptrdiff_t) *((const regset *) xx);
+  return d - dd;
 }
 #endif