[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 --- Comment #11 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-26 09:19:39 UTC --- Author: jakub Date: Mon Nov 26 09:19:30 2012 New Revision: 193806 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=193806 Log: PR tree-optimization/54471 * tree-vrp.c (extract_range_from_binary_expr_1): For MULT_EXPR, don't canonicalize range if min2 is zero. * gcc.dg/tree-ssa/vrp86.c: New test. * gcc.c-torture/execute/pr54471.c: New test. Added: trunk/gcc/testsuite/gcc.c-torture/execute/pr54471.c trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp86.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vrp.c
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 Jakub Jelinek jakub at gcc dot gnu.org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution||FIXED --- Comment #12 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-26 09:26:14 UTC --- Fixed.
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 --- Comment #3 from John David Anglin danglin at gcc dot gnu.org 2012-11-21 13:01:33 UTC --- Created attachment 28753 -- http://gcc.gnu.org/bugzilla/attachment.cgi?id=28753 Tree dump
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 --- Comment #4 from John David Anglin danglin at gcc dot gnu.org 2012-11-21 13:02:32 UTC --- Created attachment 28754 -- http://gcc.gnu.org/bugzilla/attachment.cgi?id=28754 Tree dump
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 --- Comment #5 from John David Anglin danglin at gcc dot gnu.org 2012-11-21 13:13:22 UTC --- Get the same with stage1 compiler. Maybe this is a HWI32 issue?
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471
Jakub Jelinek jakub at gcc dot gnu.org changed:
What|Removed |Added
Target|hppa*-*-* (32-bit) |
Status|WAITING |NEW
Host|hppa*-*-* (32-bit) |
Build|hppa*-*-* (32-bit) |
--- Comment #6 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-21
13:36:56 UTC ---
Reproduced with
extern void abort (void);
__attribute__ ((noinline))
unsigned __int128
foo (__int128 ixi, unsigned ctr)
{
unsigned __int128 irslt = 1;
__int128 ix = ixi;
for (; ctr; ctr--)
{
irslt *= ix;
ix *= ix;
}
if (irslt != 14348907)
abort ();
return irslt;
}
int
main ()
{
unsigned __int128 res;
res = foo (3, 4);
return 0;
}
on x86_64-linux at -O2, seems to be a VRP bug.
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 --- Comment #7 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-21 13:55:59 UTC --- Caused by http://gcc.gnu.org/viewcvs?root=gccview=revrev=190125
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471
Jakub Jelinek jakub at gcc dot gnu.org changed:
What|Removed |Added
Status|NEW |ASSIGNED
AssignedTo|unassigned at gcc dot |jakub at gcc dot gnu.org
|gnu.org |
--- Comment #8 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-21
14:42:13 UTC ---
Created attachment 28755
-- http://gcc.gnu.org/bugzilla/attachment.cgi?id=28755
gcc48-pr54471.patch
Untested fix. I believe the bug is in invalid canonicalization. When
sizem1 is { -1, -1 } double_int, sizem1 + double_int_one is { 0, 0 }, as it
wrapped, instead of { 0, 0, 1, 0 } quad_int. And if min0 or min1 is zero, then
size - min{0,1} is also zero, and so is very likely smaller than max{0,1}
(unless min{0,1} == max{0,1}), but we still don't want to canonicalize that
to signed. IMHO testing min2.is_zero () is sufficient, as min0 or min1 should
be a valid double_int in the range 0 to { -1, -1 }, which is always smaller
than the maximum unsigned integer + 1 in infinite precision and thus min2
should never be zero, unless size overflowed to 0 and min{0,1} is zero.
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471
--- Comment #9 from Marc Glisse glisse at gcc dot gnu.org 2012-11-21 17:18:47
UTC ---
Jakub, your patch makes sense to me (or min0.is_zero() and min1.is_zero()). I
am ashamed I managed to get products with [0,n] (with n larger than MAX/2)
wrong. Good thing Kenneth Zadeck's wide_int will soon allow us to remove most
of this horrible code.
Another test that shows the error (optimizes away the call to g):
void g();
void h();
void f(unsigned __int128 x){
if(x(unsigned __int128)(-3))return;
unsigned __int128 y=2*x;
if(y==42) g();
else h();
}
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471
--- Comment #10 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-21
17:31:58 UTC ---
Thanks, I'm going to include your test too then:
--- gcc/testsuite/gcc.dg/tree-ssa/vrp86.c.jj2012-11-21 18:27:53.389280736
+0100
+++ gcc/testsuite/gcc.dg/tree-ssa/vrp86.c2012-11-21 18:27:47.0
+0100
@@ -0,0 +1,26 @@
+/* PR tree-optimization/54471 */
+/* { dg-do compile } */
+/* { dg-options -O2 -fdump-tree-vrp1 } */
+
+#ifdef __SIZEOF_INT128__
+#define T __int128
+#else
+#define T long long
+#endif
+
+void fn1call ();
+void fn2call ();
+void f (unsigned T x)
+{
+ if (x (unsigned T) -3)
+return;
+ unsigned T y = 2 * x;
+ if (y == 42)
+fn1call ();
+ else
+fn2call ();
+}
+
+/* { dg-final { scan-tree-dump fn1call vrp1} } */
+/* { dg-final { scan-tree-dump fn2call vrp1} } */
+/* { dg-final { cleanup-tree-dump vrp1 } } */
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 Jakub Jelinek jakub at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |WAITING Last reconfirmed|2012-09-28 00:00:00 |2012-11-20 CC||jakub at gcc dot gnu.org Ever Confirmed|0 |1 --- Comment #1 from Jakub Jelinek jakub at gcc dot gnu.org 2012-11-20 12:06:16 UTC --- Can't reproduce that with a cross. The tree optimizers definitely don't optimize it into abort, and neither the assembly looks like what you are mentioning above.
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 --- Comment #2 from dave.anglin at bell dot net 2012-11-21 02:26:56 UTC --- On 20-Nov-12, at 7:06 AM, jakub at gcc dot gnu.org wrote: Can't reproduce that with a cross. The tree optimizers definitely don't optimize it into abort, and neither the assembly looks like what you are mentioning above. I'll recheck. I definitely remember looking at the RTL from the expand pass. That's why I marked it as a tree optimizer bug. Dave -- John David Anglindave.ang...@bell.net
[Bug tree-optimization/54471] [4.8 Regression] FAIL: gcc.dg/sms-8.c execution test
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54471 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Target Milestone|--- |4.8.0
