[src/trunk]: src/doc Document -O0 hack for ibm4xx copy{in,out}() for clang 13...

[rin <rin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/fac02ba999cf
branches:  trunk
changeset: 370009:fac02ba999cf
user:      rin <rin%NetBSD.org@localhost>
date:      Mon Sep 12 08:11:51 2022 +0000

description:
Document -O0 hack for ibm4xx copy{in,out}() for clang 13.0.0.

diffstat:

 doc/HACKS |  12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diffs (23 lines):

diff -r 9132077c756c -r fac02ba999cf doc/HACKS
--- a/doc/HACKS Mon Sep 12 08:06:36 2022 +0000
+++ b/doc/HACKS Mon Sep 12 08:11:51 2022 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: HACKS,v 1.230 2022/08/10 13:38:26 rin Exp $
+# $NetBSD: HACKS,v 1.231 2022/09/12 08:11:51 rin Exp $
 #
 # This file is intended to document workarounds for currently unsolved
 # (mostly) compiler bugs.
@@ -1054,3 +1054,13 @@
 
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105209
 kcah
+
+hack   compile copy{in,out}() for ibm4xx with -O0 for clang
+cdate  Mon Sep 12 08:06:36 UTC 2022
+who    rin
+port   evbppc
+file   sys/arch/powerpc/ibm4xx/trap.c: 1.99
+descr
+       clang 13.0.0 miscompiles copy{in,out}() with -O[12]. As a result,
+       kernel cannot execute /sbin/init.
+kcah