ia64: a few more unwind-related fixes

[David Mosberger <davidm at napali dot hpl dot hp dot com>]

Below are a couple of more unwind-related fixes to ia64-specific code.
"make check" passes as before.

	--david

2003-03-27  David Mosberger  <davidm at hpl dot hp dot com>

	* sysdeps/ia64/dl-machine.h (RTLD_START): Wrap ".save rp, r0"
	directive into empty .prologue region to ensure that call-chain
	is terminated even for the first instruction.

	* sysdeps/ia64/elf/start.S (_start): Use ".save rp, r0" idiom
	to terminate call-chain right from the get-go.

	* sysdeps/unix/sysv/linux/ia64/fork.S (fork): Remove unnecessary
	stop bit between compare & branch.

	* sysdeps/unix/sysv/linux/ia64/sysdep.S (__syscall_error):
	Bring register usage in sync with unwind info (ar.pfs is saved
	in r33, according to unwind info).

Index: sysdeps/ia64/dl-machine.h
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/ia64/dl-machine.h,v
retrieving revision 1.22
diff -u -r1.22 dl-machine.h
--- sysdeps/ia64/dl-machine.h	12 Jan 2003 08:54:00 -0000	1.22
+++ sysdeps/ia64/dl-machine.h	29 Mar 2003 06:53:06 -0000
@@ -301,8 +301,10 @@
 "_start:\n"								      \
 "0:	{ .mii\n"							      \
 "	  .prologue\n"							      \
-"	  .save ar.pfs, r32\n"						      \
 "	  .save rp, r0\n"						      \
+"	  .body\n"							      \
+"	  .prologue\n"							      \
+"	  .save ar.pfs, r32\n"						      \
 "	  alloc loc0 = ar.pfs, 0, 3, 4, 0\n"				      \
 "	  .body\n"							      \
 "	  mov r2 = ip\n"						      \
@@ -332,8 +334,10 @@
 "	.proc _dl_start_user#\n"					      \
 "_dl_start_user:\n"							      \
 "	 .prologue\n"							      \
-"	 .save ar.pfs, r32\n"						      \
 "	 .save rp, r0\n"						      \
+"	  .body\n"							      \
+"	 .prologue\n"							      \
+"	 .save ar.pfs, r32\n"						      \
 "	 .body\n"							      \
 "	{ .mii\n"							      \
 "	  /* Save the pointer to the user entry point fptr in loc2.  */\n"    \
Index: sysdeps/ia64/elf/start.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/ia64/elf/start.S,v
retrieving revision 1.11
diff -u -r1.11 start.S
--- sysdeps/ia64/elf/start.S	9 Dec 2002 20:37:21 -0000	1.11
+++ sysdeps/ia64/elf/start.S	29 Mar 2003 06:53:06 -0000
@@ -40,6 +40,9 @@
 	.type _start,@function
 _start:
 	.prologue
+	.save rp, r0
+	.body
+	.prologue
 	{ .mlx
 	  alloc r2 = ar.pfs,0,0,7,0
 	  movl r3 = FPSR_DEFAULT
@@ -76,8 +79,7 @@
 	{ .mmi
 	  ld8 out3 = [out3]	/* pointer to `init' function descriptor */
 	  ld8 out4 = [out4]	/* pointer to `fini' function descriptor */
-	  .save rp, r4
-	  mov r4 = r0		/* terminate unwind chain with a NULL return-pointer */
+	  nop 0
 	}
 	.body
 	{ .mib
Index: sysdeps/unix/sysv/linux/ia64/fork.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/ia64/fork.S,v
retrieving revision 1.6
diff -u -r1.6 fork.S
--- sysdeps/unix/sysv/linux/ia64/fork.S	31 Dec 2002 20:37:30 -0000	1.6
+++ sysdeps/unix/sysv/linux/ia64/fork.S	29 Mar 2003 06:53:07 -0000
@@ -32,7 +32,6 @@
 	;;
 	DO_CALL (SYS_ify (clone))
 	cmp.eq p6,p0=-1,r10
-	;;
 (p6)	br.cond.spnt.few __syscall_error
 	ret
 PSEUDO_END(__libc_fork)
Index: sysdeps/unix/sysv/linux/ia64/sysdep.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/ia64/sysdep.S,v
retrieving revision 1.5
diff -u -r1.5 sysdep.S
--- sysdeps/unix/sysv/linux/ia64/sysdep.S	11 Oct 2002 10:51:24 -0000	1.5
+++ sysdeps/unix/sysv/linux/ia64/sysdep.S	29 Mar 2003 06:53:07 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2000, 2001, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by David Mosberger-Tang <davidm at hpl dot hp dot com>.
 
@@ -23,18 +23,19 @@
 ENTRY(__syscall_error)
 #ifdef _LIBC_REENTRANT
 	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(0)
-	alloc	r35=ar.pfs, 0, 4, 0, 0
+	alloc	r33=ar.pfs, 0, 4, 0, 0
 	mov	r32=rp
-	mov	r33=r8
+	.body
+	mov	r35=r8
 	mov	r34=r1
 	;;
-	br.call.sptk.many b0 = __errno_location#
+	br.call.sptk.many b0 = __errno_location
 .Lret0:		/* force new bundle */
-	st4	[r8]=r33
+	st4	[r8]=r35
 	mov	r1=r34
 	mov	rp=r32
 	mov	r8=-1
-	mov	ar.pfs=r35
+	mov	ar.pfs=r33
 #else /* _LIBC_REENTRANT */
 	/*
 	 * Note that the gp has to be set properly for this to work.