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* [Bug tree-optimization/48714] New: gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly
@ 2011-04-21 18:38 arthur.j.odwyer at gmail dot com
2011-04-21 21:35 ` [Bug tree-optimization/48714] " arthur.j.odwyer at gmail dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: arthur.j.odwyer at gmail dot com @ 2011-04-21 18:38 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48714
Summary: gcc -O hangs gobbling memory, while gcc -O
-fno-tree-fre finishes quickly
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: arthur.j.odwyer@gmail.com
Created attachment 24067
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24067
Output of "ajo-gcc -v -w -O -ftree-fre -c test105974-reduced.c"
This reproduces for me with svn revision 172796 (2011-04-20), but it doesn't
reproduce with gcc-4.4. I'm on Ubuntu 10.10, x86-64. Attached "gcc-v.txt".
cat >test105974.c <<EOF
extern volatile int g_4[1][4]; extern int g_7; void modify(int *);
void func_2() {
int l_46 = 4;
if (g_7) {
modify(&l_46);
} else {
int i;
for (i = 0; i != 5; i += 1) {
volatile int *vp = &g_4[0][l_46]; *vp = 0;
}
}
}
EOF
gcc -w -O -c test105974.c
[hangs]
gcc -w -O -fno-tree-fre -c test105974.c
[passes]
This test case is reduced from the output of Csmith
(http://embed.cs.utah.edu/csmith/), using the following command line:
csmith --bitfields --packed-struct -s 105974 >test105974.c
gcc -w -I../csmith-2.0.0/runtime -O -c test105974.c
As I said, it reproduces for me only with a home-built bleeding-edge GCC, and
I'm still pretty unfamiliar with the GCC build process, so don't bite too hard
if this turns out to be user error on my end. ;)
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/48714] gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly
2011-04-21 18:38 [Bug tree-optimization/48714] New: gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly arthur.j.odwyer at gmail dot com
@ 2011-04-21 21:35 ` arthur.j.odwyer at gmail dot com
2011-04-22 9:22 ` rguenth at gcc dot gnu.org
2011-04-26 9:20 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: arthur.j.odwyer at gmail dot com @ 2011-04-21 21:35 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48714
Arthur O'Dwyer <arthur.j.odwyer at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to work| |4.4.5, 4.5.1
Version|unknown |4.7.0
--- Comment #1 from Arthur O'Dwyer <arthur.j.odwyer at gmail dot com> 2011-04-21 21:34:41 UTC ---
Here's another test case with exactly the same symptom. Again, it works with
gcc-4.4 but fails with my bleeding-edge gcc. The braces around the inner loop
are significant. Notice that the offending assignment to "gp" is actually dead
code.
cat >test106865.c <<EOF
extern volatile int g_89[5][9];
extern int g, *gp;
void func_64() {
int i;
for (i = 0; i < 1; ) {
for (g = 0; g < 1; ) {
return;
}
gp = &g_89[g][0];
}
}
EOF
gcc -w -O1 -c test106865.c
[hangs]
gcc -w -O1 -fno-tree-pre -c test106865.c
[passes]
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/48714] gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly
2011-04-21 18:38 [Bug tree-optimization/48714] New: gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly arthur.j.odwyer at gmail dot com
2011-04-21 21:35 ` [Bug tree-optimization/48714] " arthur.j.odwyer at gmail dot com
@ 2011-04-22 9:22 ` rguenth at gcc dot gnu.org
2011-04-26 9:20 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-04-22 9:22 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48714
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2011.04.22 09:21:41
Depends on| |48694
AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org
|gnu.org |
Ever Confirmed|0 |1
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-04-22 09:21:41 UTC ---
Mine. Indeed looks like 48694 - thanks for the small testcases.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/48714] gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly
2011-04-21 18:38 [Bug tree-optimization/48714] New: gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly arthur.j.odwyer at gmail dot com
2011-04-21 21:35 ` [Bug tree-optimization/48714] " arthur.j.odwyer at gmail dot com
2011-04-22 9:22 ` rguenth at gcc dot gnu.org
@ 2011-04-26 9:20 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-04-26 9:20 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48714
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |DUPLICATE
--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-04-26 09:20:14 UTC ---
Dup.
*** This bug has been marked as a duplicate of bug 48694 ***
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-04-26 9:20 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2011-04-21 18:38 [Bug tree-optimization/48714] New: gcc -O hangs gobbling memory, while gcc -O -fno-tree-fre finishes quickly arthur.j.odwyer at gmail dot com
2011-04-21 21:35 ` [Bug tree-optimization/48714] " arthur.j.odwyer at gmail dot com
2011-04-22 9:22 ` rguenth at gcc dot gnu.org
2011-04-26 9:20 ` rguenth at gcc dot gnu.org
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