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* [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu
@ 2015-08-05 7:49 su at cs dot ucdavis.edu
2015-08-05 9:12 ` [Bug tree-optimization/67121] [6 Regression] " mpolacek at gcc dot gnu.org
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: su at cs dot ucdavis.edu @ 2015-08-05 7:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
Bug ID: 67121
Summary: wrong code at -O3 on x86_64-linux-gnu
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: su at cs dot ucdavis.edu
Target Milestone: ---
The current gcc trunk miscompiles the following code on x86_64-linux-gnu at -O3
in both 32-bit and 64-bit modes.
This is a regression from 5.1.x.
$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 6.0.0 20150804 (experimental) [trunk revision 226592] (GCC)
$
$ gcc-trunk -O2 small.c; ./a.out
$ gcc-5.1 -O3 small.c; ./a.out
$
$ gcc-trunk -O3 small.c
$ ./a.out
Aborted (core dumped)
$
-----------------------------------
int a[6], b, c = 226, d, e, f;
char g;
void
fn1 (int p1)
{
b = a[p1];
}
int
main ()
{
a[0] = 1;
for (f = 0; f < 9; f++)
{
char h = c;
int i = 1;
g = h < 0 ? h : h >> i;
e = g;
for (d = 1; d; d = 0)
;
}
fn1 (g >> 8 & 1);
if (b != 0)
__builtin_abort ();
return 0;
}
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [6 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
@ 2015-08-05 9:12 ` mpolacek at gcc dot gnu.org
2015-08-05 10:43 ` rguenth at gcc dot gnu.org
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-08-05 9:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-08-05
CC| |mpolacek at gcc dot gnu.org
Target Milestone|--- |6.0
Summary|wrong code at -O3 on |[6 Regression] wrong code
|x86_64-linux-gnu |at -O3 on x86_64-linux-gnu
Ever confirmed|0 |1
--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [6 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
2015-08-05 9:12 ` [Bug tree-optimization/67121] [6 Regression] " mpolacek at gcc dot gnu.org
@ 2015-08-05 10:43 ` rguenth at gcc dot gnu.org
2015-08-05 13:06 ` mpolacek at gcc dot gnu.org
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-08-05 10:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hmm.
Visiting statement:
h_38 = (char) pretmp_48;
Found new range for h_38: VARYING
...
Visiting statement:
_42 = (int) h_38;
Intersecting
[-128, 127]
and
[0, 127]
to
[0, 127]
Found new range for _42: [0, 127]
so it seems that the old value-range for _42 is bad:
# RANGE [0, 127] NONZERO 127
_42 = (int) h_38;
Before if-conversion we have
<bb 2>:
a[0] = 1;
f = 0;
pretmp_48 = c;
<bb 3>:
# f.4_36 = PHI <0(2), _19(6)>
# ivtmp_59 = PHI <9(2), ivtmp_28(6)>
h_9 = (char) pretmp_48;
if (h_9 >= 0)
goto <bb 4>;
else
goto <bb 10>;
<bb 4>:
# RANGE [0, 127] NONZERO 127
_10 = (int) h_9;
while after:
<bb 2>:
a[0] = 1;
f = 0;
pretmp_48 = c;
<bb 3>:
# f.4_36 = PHI <0(2), _19(4)>
# ivtmp_59 = PHI <9(2), ivtmp_28(4)>
h_9 = (char) pretmp_48;
# RANGE [0, 127] NONZERO 127
_10 = (int) h_9;
...
prephitmp_3 = h_9 >= 0 ? _14 : _38;
so if-conversion has to reset value-range info on stmts previously
conditionally
executed.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [6 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
2015-08-05 9:12 ` [Bug tree-optimization/67121] [6 Regression] " mpolacek at gcc dot gnu.org
2015-08-05 10:43 ` rguenth at gcc dot gnu.org
@ 2015-08-05 13:06 ` mpolacek at gcc dot gnu.org
2015-08-05 14:17 ` rguenth at gcc dot gnu.org
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2015-08-05 13:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Started with r223863.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [6 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
` (2 preceding siblings ...)
2015-08-05 13:06 ` mpolacek at gcc dot gnu.org
@ 2015-08-05 14:17 ` rguenth at gcc dot gnu.org
2015-08-05 14:18 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-08-05 14:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Aug 5 14:16:51 2015
New Revision: 226630
URL: https://gcc.gnu.org/viewcvs?rev=226630&root=gcc&view=rev
Log:
2015-08-05 Richard Biener <rguenther@suse.de>
PR tree-optimization/67121
* tree-if-conv.c (combine_blocks): Clear range-info produced
by stmts no longer executed conditionally.
* gcc.dg/torture/pr67121.c: New testcase.
Added:
trunk/gcc/testsuite/gcc.dg/torture/pr67121.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-if-conv.c
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [5 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
` (3 preceding siblings ...)
2015-08-05 14:17 ` rguenth at gcc dot gnu.org
@ 2015-08-05 14:18 ` rguenth at gcc dot gnu.org
2015-08-05 14:18 ` [Bug tree-optimization/67121] [6 " rguenth at gcc dot gnu.org
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-08-05 14:18 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |6.0
Target Milestone|6.0 |5.3
Summary|[6 Regression] wrong code |[5 Regression] wrong code
|at -O3 on x86_64-linux-gnu |at -O3 on x86_64-linux-gnu
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Marking for backport.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [6 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
` (4 preceding siblings ...)
2015-08-05 14:18 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org
@ 2015-08-05 14:18 ` rguenth at gcc dot gnu.org
2015-09-21 9:56 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org
2015-09-21 9:58 ` rguenth at gcc dot gnu.org
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-08-05 14:18 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk but latent issue on the branches, esp. the gcc 5 branch which
also uses old ranges during VRP2.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [5 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
` (5 preceding siblings ...)
2015-08-05 14:18 ` [Bug tree-optimization/67121] [6 " rguenth at gcc dot gnu.org
@ 2015-09-21 9:56 ` rguenth at gcc dot gnu.org
2015-09-21 9:58 ` rguenth at gcc dot gnu.org
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-09-21 9:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Mon Sep 21 09:55:57 2015
New Revision: 227961
URL: https://gcc.gnu.org/viewcvs?rev=227961&root=gcc&view=rev
Log:
2015-09-21 Richard Biener <rguenther@suse.de>
Backport from mainline
2015-07-08 Richard Biener <rguenther@suse.de>
PR tree-optimization/66793
* gimple-ssa-isolate-paths.c
(insert_trap_and_remove_trailing_statemen):
Properly split the block after stmts ending it.
* gcc.dg/torture/pr66793.c: New testcase.
2015-08-05 Richard Biener <rguenther@suse.de>
PR tree-optimization/67055
* tree-ssa-ccp.c (fold_builtin_alloca_with_align): Handle
NULL gimple_block.
* g++.dg/torture/pr67055.C: New testcase.
2015-08-05 Richard Biener <rguenther@suse.de>
PR tree-optimization/67121
* tree-if-conv.c (combine_blocks): Clear range-info produced
by stmts no longer executed conditionally.
* gcc.dg/torture/pr67121.c: New testcase.
2015-09-16 Richard Biener <rguenther@suse.de>
PR middle-end/67271
* fold-const.c (native_encode_expr): Bail out on bogus offsets.
* gcc.dg/pr67271.c: New testcase.
2015-07-22 Richard Biener <rguenther@suse.de>
PR tree-optimization/66952
* tree-ssa-ifcombine.c (pass_tree_ifcombine::execute): For
blocks we end up executing unconditionally reset all SSA
info such as range and alignment.
* tree-ssanames.h (reset_flow_sensitive_info): Declare.
* tree-ssanames.c (reset_flow_sensitive_info): New function.
* gcc.dg/torture/pr66952.c: New testcase.
2015-09-15 Richard Biener <rguenther@suse.de>
PR tree-optimization/67470
* tree-ssa-loop-im.c (execute_sm_if_changed): Preserve PHI
structure for PHI hoisting by inserting a forwarder block
if appropriate.
* gcc.dg/torture/pr67470.c: New testcase.
Added:
branches/gcc-5-branch/gcc/testsuite/g++.dg/torture/pr67055.C
branches/gcc-5-branch/gcc/testsuite/gcc.dg/pr67271.c
branches/gcc-5-branch/gcc/testsuite/gcc.dg/torture/pr66793.c
branches/gcc-5-branch/gcc/testsuite/gcc.dg/torture/pr66952.c
branches/gcc-5-branch/gcc/testsuite/gcc.dg/torture/pr67121.c
branches/gcc-5-branch/gcc/testsuite/gcc.dg/torture/pr67470.c
Modified:
branches/gcc-5-branch/gcc/ChangeLog
branches/gcc-5-branch/gcc/fold-const.c
branches/gcc-5-branch/gcc/gimple-ssa-isolate-paths.c
branches/gcc-5-branch/gcc/testsuite/ChangeLog
branches/gcc-5-branch/gcc/tree-if-conv.c
branches/gcc-5-branch/gcc/tree-ssa-ccp.c
branches/gcc-5-branch/gcc/tree-ssa-ifcombine.c
branches/gcc-5-branch/gcc/tree-ssa-loop-im.c
branches/gcc-5-branch/gcc/tree-ssanames.c
branches/gcc-5-branch/gcc/tree-ssanames.h
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/67121] [5 Regression] wrong code at -O3 on x86_64-linux-gnu
2015-08-05 7:49 [Bug tree-optimization/67121] New: wrong code at -O3 on x86_64-linux-gnu su at cs dot ucdavis.edu
` (6 preceding siblings ...)
2015-09-21 9:56 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org
@ 2015-09-21 9:58 ` rguenth at gcc dot gnu.org
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2015-09-21 9:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67121
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
Known to fail| |5.2.0
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 9+ messages in thread
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2015-08-05 10:43 ` rguenth at gcc dot gnu.org
2015-08-05 13:06 ` mpolacek at gcc dot gnu.org
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2015-08-05 14:18 ` [Bug tree-optimization/67121] [5 " rguenth at gcc dot gnu.org
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