Rewrote i386 setjmp in assembly.

Thu Aug 31 13:23:35 1995  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>

	* sysdeps/unix/i386/brk.S [PIC]: Set __curbrk through the GOT.

	Rewrote i386 setjmp code in assembly, so as to avoid fighting
	with the compiler for the register values.
	* sysdeps/i386/setjmp.S, sysdeps/i386/__longjmp.S: New files.
	* sysdeps/i386/setjmp.c, sysdeps/i386/__longjmp.c: Files removed.
	* sysdeps/i386/jmp_buf.h [! _ASM] (__jmp_buf): Define as array of ints.
	[__USE_MISC || _ASM] (JB_*): New macros, for indices therein.
	(_JMPBUF_UNWINDS): Use JB_SP.

5 files changed, 84 insertions, 129 deletions

diff --git a/sysdeps/i386/__longjmp.S b/sysdeps/i386/__longjmp.S
new file mode 100644
index 0000000000..f546622828
--- /dev/null
+++ b/sysdeps/i386/__longjmp.S
@@ -0,0 +1,35 @@
+/* longjmp for i386.
+Copyright (C) 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <sysdep.h>
+#define _ASM
+#include <jmp_buf.h>
+
+ENTRY (__longjmp)
+	movl 4(%esp), %ecx	/* User's jmp_buf in %ecx.  */
+	movl 8(%esp), %eax	/* Second argument is return value.  */
+     	/* Restore registers.  */
+	movl JB_BX(%ecx), %ebx
+	movl JB_SI(%ecx), %esi
+	movl JB_DI(%ecx), %edi
+	movl JB_BP(%ecx), %ebp
+	movl JB_SP(%ecx), %esp
+	/* Jump to saved PC.  */
+     	movl JB_PC(%ecx), %ecx
+     	jmp *%ecx
diff --git a/sysdeps/i386/__longjmp.c b/sysdeps/i386/__longjmp.c
deleted file mode 100644
index 65d6ec18ec..0000000000
--- a/sysdeps/i386/__longjmp.c
+++ /dev/null
@@ -1,66 +0,0 @@
-/* Copyright (C) 1991, 1992, 1994, 1995 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB.  If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
-
-#ifndef	__GNUC__
-  #error This file uses GNU C extensions; you must compile with GCC.
-#endif
-
-/* Put these global register declarations first, because we get an error if
-   they come after any function definition, including inlines which might
-   be in some header.  */
-
-#define REGS \
-  REG (bx);\
-  REG (si);\
-  REG (di);\
-  REG (bp);\
-  REG (sp)
-
-#define REG(xx) register long int xx asm (#xx)
-REGS;
-#undef	REG
-
-#include <ansidecl.h>
-#include <errno.h>
-#include <setjmp.h>
-#include <stdlib.h>
-
-/* Jump to the position specified by ENV, causing the
-   setjmp call there to return VAL, or 1 if VAL is 0.  */
-void
-DEFUN(__longjmp, (env, val),
-      __jmp_buf env AND int val)
-{
-  /* We specify explicit registers because, when not optimizing,
-     the compiler will generate code that uses the frame pointer
-     after it's been munged.  */
-
-  register CONST __typeof (env[0]) *e asm ("cx");
-  register int v asm ("ax");
-
-  e = env;
-  v = val == 0 ? 1 : val;
-
-#define	REG(xx)	xx = (long int) e->__##xx
-  REGS;
-
-  asm volatile ("jmp %*%0" : : "g" (e->__pc), "a" (v));
-
-  /* NOTREACHED */
-  abort ();
-}
diff --git a/sysdeps/i386/jmp_buf.h b/sysdeps/i386/jmp_buf.h
index 7949883b60..0c03073b36 100644
--- a/sysdeps/i386/jmp_buf.h
+++ b/sysdeps/i386/jmp_buf.h
@@ -1,14 +1,19 @@
 /* Define the machine-dependent type `jmp_buf'.  Intel 386 version.  */
 
-typedef struct
-  {
-    long int __bx, __si, __di;
-    __ptr_t __bp;
-    __ptr_t __sp;
-    __ptr_t __pc;
-  } __jmp_buf[1];
+#if	defined (__USE_MISC) || defined (_ASM)
+#define	JB_BX	0
+#define	JB_SI	1
+#define	JB_DI	2
+#define	JB_BP	3
+#define	JB_SP	4
+#define	JB_PC	5
+#endif
+
+#ifndef	_ASM
+typedef int __jmp_buf[6];
+#endif
 
 /* Test if longjmp to JMPBUF would unwind the frame
    containing a local variable at ADDRESS.  */
 #define _JMPBUF_UNWINDS(jmpbuf, address) \
-  ((__ptr_t) (address) < (jmpbuf)[0].__sp)
+  ((int) (address) < (jmpbuf)[JB_SP])
diff --git a/sysdeps/i386/setjmp.S b/sysdeps/i386/setjmp.S
new file mode 100644
index 0000000000..a07d6f1137
--- /dev/null
+++ b/sysdeps/i386/setjmp.S
@@ -0,0 +1,36 @@
+/* setjmp for i386.
+Copyright (C) 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <sysdep.h>
+#define _ASM
+#include <jmp_buf.h>
+
+ENTRY (__sigsetjmp)
+	movl 4(%esp), %eax	/* User's jmp_buf in %eax.  */
+     	/* Save registers.  */
+	movl %ebx, JB_BX(%eax)
+	movl %esi, JB_SI(%eax)
+	movl %edi, JB_DI(%eax)
+	movl %ebp, JB_BP(%eax)
+	leal 4(%esp), %ecx	/* Save SP as it will be after we return.  */
+     	movl %ecx, JB_SP(%eax)
+	movl 0(%esp), %ecx	/* Save PC we are returning to now.  */
+     	movl %ecx, JB_PC(%eax)
+	xorl %eax, %eax		/* Return zero.  */
+	ret
diff --git a/sysdeps/i386/setjmp.c b/sysdeps/i386/setjmp.c
deleted file mode 100644
index fb8fc98659..0000000000
--- a/sysdeps/i386/setjmp.c
+++ /dev/null
@@ -1,55 +0,0 @@
-/* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB.  If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
-
-/* Put these global register declarations first, because we get an error if
-   they come after any function definition, including inlines which might
-   be in some header.  */
-
-#define REGS \
-  REG (bx);\
-  REG (si);\
-  REG (di)
-
-#define REG(xx) register long int xx asm (#xx)
-REGS;
-#undef	REG
-
-#include <errno.h>
-#include <setjmp.h>
-
-/* Save the current program position in ENV and return 0.  */
-int
-__sigsetjmp (jmp_buf env, int savemask)
-{
-  /* Save the general registers.  */
-#define	REG(xx)	env[0].__jmpbuf[0].__##xx = xx
-  REGS;
-#undef REG
-
-  /* Save the return PC.  */
-  env[0].__jmpbuf[0].__pc = ((void **) &env)[-1];
-
-  /* Save caller's FP, not our own.  */
-  env[0].__jmpbuf[0].__bp = ((void **) &env)[-2];
-
-  /* Save caller's SP, not our own.  */
-  env[0].__jmpbuf[0].__sp = (void *) &env;
-
-  /* Save the signal mask if requested.  */
-  return __sigjmp_save (env, savemask);
-}