Install a workaround for a longstanding gcc bug that allows SIGFPE traps

to occur for division by zero, even though the code is carefully avoiding
that.  All available evidence is that the only functions affected are
int24div, int48div, and int28div, so patch just those three functions to
include a "return" after the ereport() call.

Backpatch to 8.4 so that the fix can be tested in production builds.
For older branches our recommendation will continue to be to use -O1
on affected platforms (which are mostly non-mainstream anyway).
This commit is contained in:
Tom Lane 2009-09-03 18:48:14 +00:00
parent fc19373993
commit d0a368c656
2 changed files with 17 additions and 2 deletions

View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/int.c,v 1.84 2009/01/01 17:23:49 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/int.c,v 1.85 2009/09/03 18:48:14 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -950,9 +950,14 @@ int24div(PG_FUNCTION_ARGS)
int32 arg2 = PG_GETARG_INT32(1);
if (arg2 == 0)
{
ereport(ERROR,
(errcode(ERRCODE_DIVISION_BY_ZERO),
errmsg("division by zero")));
/* ensure compiler realizes we mustn't reach the division (gcc bug) */
PG_RETURN_NULL();
}
/* No overflow is possible */
PG_RETURN_INT32((int32) arg1 / arg2);
}

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/int8.c,v 1.74 2009/06/11 14:49:03 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/int8.c,v 1.75 2009/09/03 18:48:14 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -919,9 +919,14 @@ int48div(PG_FUNCTION_ARGS)
int64 arg2 = PG_GETARG_INT64(1);
if (arg2 == 0)
{
ereport(ERROR,
(errcode(ERRCODE_DIVISION_BY_ZERO),
errmsg("division by zero")));
/* ensure compiler realizes we mustn't reach the division (gcc bug) */
PG_RETURN_NULL();
}
/* No overflow is possible */
PG_RETURN_INT64((int64) arg1 / arg2);
}
@ -1098,9 +1103,14 @@ int28div(PG_FUNCTION_ARGS)
int64 arg2 = PG_GETARG_INT64(1);
if (arg2 == 0)
{
ereport(ERROR,
(errcode(ERRCODE_DIVISION_BY_ZERO),
errmsg("division by zero")));
/* ensure compiler realizes we mustn't reach the division (gcc bug) */
PG_RETURN_NULL();
}
/* No overflow is possible */
PG_RETURN_INT64((int64) arg1 / arg2);
}