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* [Bug c/27136] New: Compile failure with -O -ffast-math
@ 2006-04-12 17:25 trt at acm dot org
2006-04-13 1:37 ` [Bug middle-end/27136] [4.0/4.1/4.2 Regression] " pinskia at gcc dot gnu dot org
` (10 more replies)
0 siblings, 11 replies; 12+ messages in thread
From: trt at acm dot org @ 2006-04-12 17:25 UTC (permalink / raw)
To: gcc-bugs
This program, compiled -O -ffast-math, seems to consume infinite stack space
/* -O -ffast-math */
void foo()
{
double x;
for (x = 2; x < 10; x *= x)
;
}
--
Summary: Compile failure with -O -ffast-math
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: trt at acm dot org
GCC host triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
@ 2006-04-13 1:37 ` pinskia at gcc dot gnu dot org
2006-04-17 10:34 ` rguenth at gcc dot gnu dot org
` (9 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-04-13 1:37 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2006-04-13 01:37 -------
Confirmed.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Component|c |middle-end
Ever Confirmed|0 |1
Keywords| |ice-on-valid-code
Known to fail| |4.0.0 4.1.0 4.2.0
Known to work| |3.4.0
Last reconfirmed|0000-00-00 00:00:00 |2006-04-13 01:37:35
date| |
Summary|Compile failure with -O - |[4.0/4.1/4.2 Regression]
|ffast-math |Compile failure with -O -
| |ffast-math
Target Milestone|--- |4.0.4
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
2006-04-13 1:37 ` [Bug middle-end/27136] [4.0/4.1/4.2 Regression] " pinskia at gcc dot gnu dot org
@ 2006-04-17 10:34 ` rguenth at gcc dot gnu dot org
2006-04-17 10:51 ` rguenth at gcc dot gnu dot org
` (8 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-04-17 10:34 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from rguenth at gcc dot gnu dot org 2006-04-17 10:34 -------
#5 0x081a8738 in get_val_for (x=0xb7dedea0, base=0xb7d70480)
at /space/rguenther/src/svn/gcc-4_1-branch/gcc/tree-ssa-loop-niter.c:1254
1254 val = fold (TREE_OPERAND (stmt, 1));
(gdb) call debug_generic_expr(stmt)
xD.1278_3 = __builtin_pow (4.0e+0, 2.0e+0)
which we don't evaluate at compile-time. So loop_niter_by_eval builds
(gdb) call debug_generic_expr(expr)
__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow (__builtin_pow
(__builtin_pow ......
on which we punt at some point. Now, we definitely should fold 4.0**2.0 at
compile time, too.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org, rakdver at gcc dot gnu
| |dot org
Keywords| |missed-optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
2006-04-13 1:37 ` [Bug middle-end/27136] [4.0/4.1/4.2 Regression] " pinskia at gcc dot gnu dot org
2006-04-17 10:34 ` rguenth at gcc dot gnu dot org
@ 2006-04-17 10:51 ` rguenth at gcc dot gnu dot org
2006-04-17 11:12 ` rguenth at gcc dot gnu dot org
` (7 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-04-17 10:51 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from rguenth at gcc dot gnu dot org 2006-04-17 10:51 -------
Hmm, looks more like a tree sharing problem
Breakpoint 5, fold_ternary (code=CALL_EXPR, type=0xb7d5fa6c, op0=0xb7d55540,
op1=0xb7dd9048, op2=0x0)
at /space/rguenther/src/svn/gcc-4_1-branch/gcc/fold-const.c:9945
9945 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
(gdb) call debug_tree(op1)
<tree_list 0xb7dd9048
value <call_expr 0xb7dd1028
type <real_type 0xb7d5fa6c double sizes-gimplified DF
size <integer_cst 0xb7d50540 constant invariant 64>
unit size <integer_cst 0xb7d50558 constant invariant 8>
align 64 symtab 0 alias set -1 precision 64
pointer_to_this <pointer_type 0xb7d5fb80>>
nothrow
arg 0 <addr_expr 0xb7d55240 type <pointer_type 0xb7dcf3f4>
readonly constant invariant arg 0 <function_decl 0xb7d80d80
__builtin_pow>>
arg 1 <tree_list 0xb7dd67e0 value <call_expr 0xb7dd1028>
chain <tree_list 0xb7dd67c8
value <real_cst 0xb7dd6798 type <real_type 0xb7d5fa6c double>
constant invariant 2.0e+0>>>
t.c:5>
chain <tree_list 0xb7dd9030
value <real_cst 0xb7dd9000 type <real_type 0xb7d5fa6c double>
constant invariant 3.2e+1>>>
we are self-referencing and so built up an infinite chain of pow (pow (..., 2)
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords|missed-optimization |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (2 preceding siblings ...)
2006-04-17 10:51 ` rguenth at gcc dot gnu dot org
@ 2006-04-17 11:12 ` rguenth at gcc dot gnu dot org
2006-04-17 11:18 ` rguenth at gcc dot gnu dot org
` (6 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-04-17 11:12 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from rguenth at gcc dot gnu dot org 2006-04-17 11:12 -------
1329 aval[j] = get_val_for (op[j], val[j]);
(gdb) call debug_generic_expr(val[0])
__builtin_pow (xD.1278_4, 2.0e+0)
(gdb) call debug_generic_expr(op[0])
xD.1278_3
Program received signal SIGSEGV, Segmentation fault.
0x08316db6 in operand_equal_p (arg0=0xb7dc0798, arg1=0xb7c556c0, flags=0)
at /space/rguenther/src/svn/gcc-4_1-branch/gcc/fold-const.c:2423
2423 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE
(arg1)))
I think the brute-force evaluation should stop as soon as val[i] is no longer
a constant.
get_val_for (x=0xb7d3aea0, base=0xb7d39028)
at /space/rguenther/src/svn/gcc-4_1-branch/gcc/tree-ssa-loop-niter.c:1242
1246 if (TREE_CODE (stmt) == PHI_NODE)
(gdb) call debug_generic_expr(stmt)
xD.1278_3 = __builtin_pow (xD.1278_4, 2.0e+0)
(gdb) call debug_generic_expr(x)
xD.1278_3
(gdb) call debug_generic_expr(base)
__builtin_pow (xD.1278_4, 2.0e+0)
now, stmt is the same as the stmt of the first use.
get_val_for (x=0xb7d40104, base=0xb7d39028)
at /space/rguenther/src/svn/gcc-4_1-branch/gcc/tree-ssa-loop-niter.c:1242
1242 if (!x)
(gdb) finish
Value returned is $11 = (union tree_node *) 0xb7d39028
(gdb) call debug_generic_expr($11)
__builtin_pow (xD.1278_4, 2.0e+0)
1253 SET_USE (op, val);
kaboom. We just created a self-referencing tree here. Now, either punt on
non-constant/SSA_NAME val, or unshare val, or punt earlier.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (3 preceding siblings ...)
2006-04-17 11:12 ` rguenth at gcc dot gnu dot org
@ 2006-04-17 11:18 ` rguenth at gcc dot gnu dot org
2006-04-17 13:10 ` patchapp at dberlin dot org
` (5 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-04-17 11:18 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from rguenth at gcc dot gnu dot org 2006-04-17 11:18 -------
Now, the comment before get_val_for is confusing, as it says
* if BASE is NULL_TREE, X must be a constant and we return X.
but we do
if (!x)
return base;
now, I believe a
gcc_assert (is_gimple_min_invariant (base));
before this statement is what needs to hold. So the caller needs to be fixed.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (4 preceding siblings ...)
2006-04-17 11:18 ` rguenth at gcc dot gnu dot org
@ 2006-04-17 13:10 ` patchapp at dberlin dot org
2006-05-07 13:07 ` rguenth at gcc dot gnu dot org
` (4 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: patchapp at dberlin dot org @ 2006-04-17 13:10 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from patchapp at dberlin dot org 2006-04-17 13:10 -------
Subject: Bug number PR 27136
A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2006-04/msg00623.html
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1/4.2 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (5 preceding siblings ...)
2006-04-17 13:10 ` patchapp at dberlin dot org
@ 2006-05-07 13:07 ` rguenth at gcc dot gnu dot org
2006-05-07 13:13 ` [Bug middle-end/27136] [4.0/4.1 " rguenth at gcc dot gnu dot org
` (3 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-05-07 13:07 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from rguenth at gcc dot gnu dot org 2006-05-07 13:07 -------
Subject: Bug 27136
Author: rguenth
Date: Sun May 7 13:07:22 2006
New Revision: 113601
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113601
Log:
2006-05-07 Richard Guenther <rguenther@suse.de>
PR tree-optimization/27136
* tree-ssa-loop-niter.c (get_val_for): Correct function
comment, assert requirements.
(loop_niter_by_eval): Stop processing if the iterated
value did not simplify.
* gcc.dg/torture/pr27136.c: New testcase.
Added:
trunk/gcc/testsuite/gcc.dg/torture/pr27136.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/testsuite/ChangeLog
trunk/gcc/tree-ssa-loop-niter.c
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (6 preceding siblings ...)
2006-05-07 13:07 ` rguenth at gcc dot gnu dot org
@ 2006-05-07 13:13 ` rguenth at gcc dot gnu dot org
2006-05-09 15:56 ` rguenth at gcc dot gnu dot org
` (2 subsequent siblings)
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-05-07 13:13 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from rguenth at gcc dot gnu dot org 2006-05-07 13:13 -------
Fixed on the mainline.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |rguenth at gcc dot gnu dot
|dot org |org
Status|NEW |ASSIGNED
Known to fail|4.0.0 4.1.0 4.2.0 |4.0.0 4.1.0
Known to work|3.4.0 |3.4.0 4.2.0
Last reconfirmed|2006-04-13 01:37:35 |2006-05-07 13:13:02
date| |
Summary|[4.0/4.1/4.2 Regression] |[4.0/4.1 Regression] Compile
|Compile failure with -O - |failure with -O -ffast-math
|ffast-math |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (7 preceding siblings ...)
2006-05-07 13:13 ` [Bug middle-end/27136] [4.0/4.1 " rguenth at gcc dot gnu dot org
@ 2006-05-09 15:56 ` rguenth at gcc dot gnu dot org
2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-05-09 15:56 UTC (permalink / raw)
To: gcc-bugs
------- Comment #9 from rguenth at gcc dot gnu dot org 2006-05-09 15:56 -------
Subject: Bug 27136
Author: rguenth
Date: Tue May 9 15:56:12 2006
New Revision: 113656
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113656
Log:
2006-05-09 Richard Guenther <rguenther@suse.de>
PR tree-optimization/27136
* tree-ssa-loop-niter.c (get_val_for): Correct function
comment, assert requirements.
(loop_niter_by_eval): Stop processing if the iterated
value did not simplify.
* gcc.dg/torture/pr27136.c: New testcase.
Added:
branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/torture/pr27136.c
- copied unchanged from r113601,
trunk/gcc/testsuite/gcc.dg/torture/pr27136.c
Modified:
branches/gcc-4_1-branch/gcc/ChangeLog
branches/gcc-4_1-branch/gcc/testsuite/ChangeLog
branches/gcc-4_1-branch/gcc/tree-ssa-loop-niter.c
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (8 preceding siblings ...)
2006-05-09 15:56 ` rguenth at gcc dot gnu dot org
@ 2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-05-09 16:02 UTC (permalink / raw)
To: gcc-bugs
------- Comment #11 from rguenth at gcc dot gnu dot org 2006-05-09 16:02 -------
Fixed.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug middle-end/27136] [4.0/4.1 Regression] Compile failure with -O -ffast-math
2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
` (9 preceding siblings ...)
2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
@ 2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
10 siblings, 0 replies; 12+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-05-09 16:02 UTC (permalink / raw)
To: gcc-bugs
------- Comment #10 from rguenth at gcc dot gnu dot org 2006-05-09 16:02 -------
Subject: Bug 27136
Author: rguenth
Date: Tue May 9 16:01:53 2006
New Revision: 113657
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113657
Log:
2006-05-09 Richard Guenther <rguenther@suse.de>
PR tree-optimization/27136
* tree-ssa-loop-niter.c (get_val_for): Correct function
comment, assert requirements.
(loop_niter_by_eval): Stop processing if the iterated
value did not simplify.
* gcc.dg/torture/pr27136.c: New testcase.
Added:
branches/gcc-4_0-branch/gcc/testsuite/gcc.dg/torture/pr27136.c
- copied unchanged from r113601,
trunk/gcc/testsuite/gcc.dg/torture/pr27136.c
Modified:
branches/gcc-4_0-branch/gcc/ChangeLog
branches/gcc-4_0-branch/gcc/testsuite/ChangeLog
branches/gcc-4_0-branch/gcc/tree-ssa-loop-niter.c
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27136
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2006-05-09 16:02 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
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2006-04-12 17:25 [Bug c/27136] New: Compile failure with -O -ffast-math trt at acm dot org
2006-04-13 1:37 ` [Bug middle-end/27136] [4.0/4.1/4.2 Regression] " pinskia at gcc dot gnu dot org
2006-04-17 10:34 ` rguenth at gcc dot gnu dot org
2006-04-17 10:51 ` rguenth at gcc dot gnu dot org
2006-04-17 11:12 ` rguenth at gcc dot gnu dot org
2006-04-17 11:18 ` rguenth at gcc dot gnu dot org
2006-04-17 13:10 ` patchapp at dberlin dot org
2006-05-07 13:07 ` rguenth at gcc dot gnu dot org
2006-05-07 13:13 ` [Bug middle-end/27136] [4.0/4.1 " rguenth at gcc dot gnu dot org
2006-05-09 15:56 ` rguenth at gcc dot gnu dot org
2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
2006-05-09 16:02 ` rguenth at gcc dot gnu dot org
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