[src/netbsd-6]: src/lib/libc/arch/alpha/gen Pull up following revision(s) (re...

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

details:   https://anonhg.NetBSD.org/src/rev/9c0ff51280f8
branches:  netbsd-6
changeset: 775734:9c0ff51280f8
user:      riz <riz%NetBSD.org@localhost>
date:      Thu Mar 14 22:36:05 2013 +0000

description:
Pull up following revision(s) (requested by martin in ticket #846):
        lib/libc/arch/alpha/gen/__setjmp14.S: revision 1.6
        lib/libc/arch/alpha/gen/__longjmp14.c: revision 1.6
        lib/libc/arch/alpha/gen/__longjmp14.c: revision 1.7
Save the GP register value and restore it on longjmp.
While formally GP is not a callee-saved register, for static linking
the link time optimization described in section 3.2.3 of the "Calling
Standard for Alpha Systems" allows the caller to rely on GP being the
value needed within setjmp() - and not restore it after return if setjmp
and the call site share a GP value.
This fixes longjmp/setjmp for statically linked programs, e.g. /rescue/csh
or the static tcsh variant from pkgsrc.
Remove clearing of ucontext_t, the only random register values now are
argument and scratch registers (which will be reloaded after return anyway).

diffstat:

 lib/libc/arch/alpha/gen/__longjmp14.c |  3 ++-
 lib/libc/arch/alpha/gen/__setjmp14.S  |  3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diffs (34 lines):

diff -r a6d1fa5a86eb -r 9c0ff51280f8 lib/libc/arch/alpha/gen/__longjmp14.c
--- a/lib/libc/arch/alpha/gen/__longjmp14.c     Thu Mar 14 22:33:15 2013 +0000
+++ b/lib/libc/arch/alpha/gen/__longjmp14.c     Thu Mar 14 22:36:05 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: __longjmp14.c,v 1.5 2008/04/28 20:22:55 martin Exp $   */
+/*     $NetBSD: __longjmp14.c,v 1.5.24.1 2013/03/14 22:36:06 riz Exp $ */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -74,6 +74,7 @@
        uc.uc_mcontext.__gregs[_REG_S5] = sc->sc_regs[R_S5];
        uc.uc_mcontext.__gregs[_REG_S6] = sc->sc_regs[R_S6];
        uc.uc_mcontext.__gregs[_REG_RA] = sc->sc_regs[R_RA];
+       uc.uc_mcontext.__gregs[_REG_GP] = sc->sc_regs[R_GP];
        uc.uc_mcontext.__gregs[_REG_SP] = sc->sc_sp;
        uc.uc_mcontext.__gregs[_REG_PC] = sc->sc_pc;
        uc.uc_mcontext.__gregs[_REG_PS] =
diff -r a6d1fa5a86eb -r 9c0ff51280f8 lib/libc/arch/alpha/gen/__setjmp14.S
--- a/lib/libc/arch/alpha/gen/__setjmp14.S      Thu Mar 14 22:33:15 2013 +0000
+++ b/lib/libc/arch/alpha/gen/__setjmp14.S      Thu Mar 14 22:36:05 2013 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: __setjmp14.S,v 1.5 2011/06/12 05:44:36 matt Exp $ */
+/* $NetBSD: __setjmp14.S,v 1.5.4.1 2013/03/14 22:36:05 riz Exp $ */
 
 /*
  * Copyright (c) 1994, 1995 Carnegie-Mellon University.
@@ -55,6 +55,7 @@
        stq     s6, (SC_REGS+_REG_S6)(a0)
        stq     ra, (SC_REGS+_REG_RA)(a0)
        stq     sp, (SC_REGS+_REG_SP)(a0)
+       stq     gp, (SC_REGS+_REG_GP)(a0)
 
        /*
         * get signal information