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[patch] Bump size of stack checking protection area
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Mon, 14 Sep 2015 10:23:16 +0200
- Subject: [patch] Bump size of stack checking protection area
- Authentication-results: sourceware.org; auth=none
Hi,
as documented, STACK_CHECK_PROTECT is supposed to be an "estimate of the
amount of stack required to propagate an exception". It's (mainly) for Ada
and it needs to distinguish the various EH schemes, which might have different
needs. While the current setting is OK for the front-end SJLJ scheme used up
to now in Ada, it's not sufficient for the middle-end SJLJ scheme that we are
experimenting with; you need 8K on some platforms to pass the ACATS testsuite.
Tested on x86_64-suse-linux, OK for the mainline?
2015-09-14 Eric Botcazou <ebotcazou@adacore.com>
* defaults.h (STACK_OLD_CHECK_PROTECT): Adjust for -fno-exceptions.
Bump to 4K for SJLJ exceptions.
(STACK_CHECK_PROTECT): Likewise. Bump to 8K for SJLJ exceptions.
--
Eric Botcazou
Index: defaults.h
===================================================================
--- defaults.h (revision 227729)
+++ defaults.h (working copy)
@@ -1406,9 +1406,11 @@ see the files COPYING3 and COPYING.RUNTI
#define STACK_OLD_CHECK_PROTECT STACK_CHECK_PROTECT
#else
#define STACK_OLD_CHECK_PROTECT \
- (targetm_common.except_unwind_info (&global_options) == UI_SJLJ \
+ (!global_options.x_flag_exceptions \
? 75 * UNITS_PER_WORD \
- : 8 * 1024)
+ : targetm_common.except_unwind_info (&global_options) == UI_SJLJ \
+ ? 4 * 1024 \
+ : 8 * 1024)
#endif
/* Minimum amount of stack required to recover from an anticipated stack
@@ -1416,9 +1418,11 @@ see the files COPYING3 and COPYING.RUNTI
of stack required to propagate an exception. */
#ifndef STACK_CHECK_PROTECT
#define STACK_CHECK_PROTECT \
- (targetm_common.except_unwind_info (&global_options) == UI_SJLJ \
- ? 75 * UNITS_PER_WORD \
- : 12 * 1024)
+ (!global_options.x_flag_exceptions \
+ ? 4 * 1024 \
+ : targetm_common.except_unwind_info (&global_options) == UI_SJLJ \
+ ? 8 * 1024 \
+ : 12 * 1024)
#endif
/* Make the maximum frame size be the largest we can and still only need