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* [Bug optimization/14593] New: [tree-ssa] bcopy is mysteriously replaced with memcpy
@ 2004-03-16 4:32 kazu at cs dot umass dot edu
2004-03-16 4:34 ` [Bug optimization/14593] " kazu at cs dot umass dot edu
2004-03-16 4:43 ` pinskia at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: kazu at cs dot umass dot edu @ 2004-03-16 4:32 UTC (permalink / raw)
To: gcc-bugs
Reduced from gcc.c-torture/execute/builtins/string-asm-2*
typedef __SIZE_TYPE__ size_t;
extern void abort (void);
extern void bcopy (const void *, void *, size_t);
char y[64] = "foX";
void *
memcpy (void *d, const void *s, size_t n)
{
char *dst = (char *) d;
const char *src = (const char *) s;
while (n--)
*dst++ = *src++;
return (char *) d;
}
int
main (void)
{
bcopy (y + 1, y + 2, 3);
if (y[3] != 'X')
abort ();
return 0;
}
With -O0, bcopy stays as is in the final assembly output.
With -O1 and above, bcopy is somehow transformed into memcpy.
This problem seems to occur at expand-time.
On mainline, this problem does not exist.
--
Summary: [tree-ssa] bcopy is mysteriously replaced with memcpy
Product: gcc
Version: tree-ssa
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: kazu at cs dot umass dot edu
CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: h8300-elf
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14593
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug optimization/14593] [tree-ssa] bcopy is mysteriously replaced with memcpy
2004-03-16 4:32 [Bug optimization/14593] New: [tree-ssa] bcopy is mysteriously replaced with memcpy kazu at cs dot umass dot edu
@ 2004-03-16 4:34 ` kazu at cs dot umass dot edu
2004-03-16 4:43 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: kazu at cs dot umass dot edu @ 2004-03-16 4:34 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From kazu at cs dot umass dot edu 2004-03-16 04:34 -------
Note that on this testcase, bcopy must stay as is because
source and destination of bcopy overlap.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14593
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug optimization/14593] [tree-ssa] bcopy is mysteriously replaced with memcpy
2004-03-16 4:32 [Bug optimization/14593] New: [tree-ssa] bcopy is mysteriously replaced with memcpy kazu at cs dot umass dot edu
2004-03-16 4:34 ` [Bug optimization/14593] " kazu at cs dot umass dot edu
@ 2004-03-16 4:43 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-03-16 4:43 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-03-16 04:43 -------
This is an almost exact (very close in fact references the same test case even) dup of bug 14197.
*** This bug has been marked as a duplicate of 14197 ***
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14593
^ permalink raw reply [flat|nested] 3+ messages in thread
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2004-03-16 4:32 [Bug optimization/14593] New: [tree-ssa] bcopy is mysteriously replaced with memcpy kazu at cs dot umass dot edu
2004-03-16 4:34 ` [Bug optimization/14593] " kazu at cs dot umass dot edu
2004-03-16 4:43 ` pinskia at gcc dot gnu dot org
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