[Bug optimization/14593] New: [tree-ssa] bcopy is mysteriously replaced with memcpy
kazu at cs dot umass dot edu
gcc-bugzilla@gcc.gnu.org
Tue Mar 16 04:32:00 GMT 2004
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
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