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ARM setjmp/longjmp support for iWMMXt
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: libc-ports at sourceware dot org
- Date: Fri, 18 Aug 2006 23:13:41 +0000 (UTC)
- Subject: ARM setjmp/longjmp support for iWMMXt
This patch teaches glibc's ARM EABI setjmp and longjmp to save and restore
iWMMXt registers, if they are present and the kernel announces this with
HWCAP_IWMMXT, as done for VFP registers. The HWCAP_IWMMXT setting has
been accepted for the kernel, see
<http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=3756/1>.
At present, these functions get HWCAP_VFP from <asm/procinfo.h>. Getting
HWCAP_IWMMXT that way would be a problem because it would require very new
git kernel headers; making the code conditional on the define might also
be undesirable, since the kernel headers don't necessarily correspond
exactly to the kernel being used at runtime.
Use of <asm/procinfo.h>, a Linux-specific kernel header, in
sysdeps/arm/eabi, is also an abstraction violation. glibc already
hardcodes a list of HWCAP values in dl-procinfo.h and dl-procinfo.c. I
decided it would be better to move the hardcoded list to use #defines and
be in sysdep.h, so that they can be used from assembly. (PowerPC also
uses #defines in sysdep.h for HWCAP values.) So this patch follows that
approach. (In principle I think all the other files in sysdeps/arm/eabi
should also use sysdep.h not asm/procinfo.h for HWCAP_VFP.)
2006-08-18 Joseph Myers <joseph@codesourcery.com>
* sysdeps/unix/sysv/linux/arm/dl-procinfo.c (_dl_arm_cap_flags):
Add "java" and "iwmmxt".
* sysdeps/unix/sysv/linux/arm/dl-procinfo.h: Use <sysdep.h> for
HWCAP values.
(_DL_HWCAP_COUNT): Increase to 10.
* sysdeps/unix/sysv/linux/arm/sysdep.h (HWCAP_ARM_SWP,
HWCAP_ARM_HALF, HWCAP_ARM_THUMB, HWCAP_ARM_26BIT,
HWCAP_ARM_FAST_MULT, HWCAP_ARM_FPA, HWCAP_ARM_VFP, HWCAP_ARM_EDSP,
HWCAP_ARM_JAVA, HWCAP_ARM_IWMMXT): Define.
* sysdeps/arm/eabi/setjmp.S (__sigsetjmp): Save iWMMXt registers
if HWCAP_ARM_IWMMXT set. Don't include <asm/procinfo.h>. Use
HWCAP_ARM_VFP instead of HWCAP_VFP.
* sysdeps/arm/eabi/__longjmp.S (__longjmp): Restore iWMMXt
registers if HWCAP_ARM_IWMMXT set. Don't include
<asm/procinfo.h>. Use HWCAP_ARM_VFP instead of HWCAP_VFP.
Index: sysdeps/arm/eabi/__longjmp.S
===================================================================
RCS file: /cvs/glibc/ports/sysdeps/arm/eabi/__longjmp.S,v
retrieving revision 1.1
diff -u -r1.1 __longjmp.S
--- sysdeps/arm/eabi/__longjmp.S 10 Oct 2005 15:29:32 -0000 1.1
+++ sysdeps/arm/eabi/__longjmp.S 18 Aug 2006 23:12:07 -0000
@@ -1,5 +1,5 @@
/* longjmp for ARM.
- Copyright (C) 1997, 1998, 2005 Free Software Foundation, Inc.
+ Copyright (C) 1997, 1998, 2005, 2006 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
@@ -21,8 +21,6 @@
#define _SETJMP_H
#define _ASM
#include <bits/setjmp.h>
-#define __ASSEMBLY__
-#include <asm/procinfo.h>
#include <rtld-global-offsets.h>
/* __longjmp(jmpbuf, val) */
@@ -53,7 +51,7 @@
#endif
#endif
- tst a2, #HWCAP_VFP
+ tst a2, #HWCAP_ARM_VFP
beq Lno_vfp
/* Restore the VFP registers. */
@@ -65,6 +63,19 @@
mcr p10, 7, r1, cr1, cr0, 0
Lno_vfp:
+ tst a2, #HWCAP_ARM_IWMMXT
+ beq Lno_iwmmxt
+
+ /* Restore the call-preserved iWMMXt registers. */
+ /* Following instructions are wldrd wr10, [ip], #8 (etc.) */
+ ldcl p1, cr10, [r12], #8
+ ldcl p1, cr11, [r12], #8
+ ldcl p1, cr12, [r12], #8
+ ldcl p1, cr13, [r12], #8
+ ldcl p1, cr14, [r12], #8
+ ldcl p1, cr15, [r12], #8
+Lno_iwmmxt:
+
DO_RET(lr)
#ifdef IS_IN_rtld
Index: sysdeps/arm/eabi/setjmp.S
===================================================================
RCS file: /cvs/glibc/ports/sysdeps/arm/eabi/setjmp.S,v
retrieving revision 1.1
diff -u -r1.1 setjmp.S
--- sysdeps/arm/eabi/setjmp.S 10 Oct 2005 15:29:32 -0000 1.1
+++ sysdeps/arm/eabi/setjmp.S 18 Aug 2006 23:12:07 -0000
@@ -1,5 +1,5 @@
/* setjmp for ARM.
- Copyright (C) 1997, 1998, 2005 Free Software Foundation, Inc.
+ Copyright (C) 1997, 1998, 2005, 2006 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
@@ -21,8 +21,6 @@
#define _SETJMP_H
#define _ASM
#include <bits/setjmp.h>
-#define __ASSEMBLY__
-#include <asm/procinfo.h>
#include <rtld-global-offsets.h>
ENTRY (__sigsetjmp)
@@ -51,7 +49,7 @@
#endif
#endif
- tst a3, #HWCAP_VFP
+ tst a3, #HWCAP_ARM_VFP
beq Lno_vfp
/* Store the VFP registers. */
@@ -63,6 +61,19 @@
str r2, [ip], #4
Lno_vfp:
+ tst a3, #HWCAP_ARM_IWMMXT
+ beq Lno_iwmmxt
+
+ /* Save the call-preserved iWMMXt registers. */
+ /* Following instructions are wstrd wr10, [ip], #8 (etc.) */
+ stcl p1, cr10, [r12], #8
+ stcl p1, cr11, [r12], #8
+ stcl p1, cr12, [r12], #8
+ stcl p1, cr13, [r12], #8
+ stcl p1, cr14, [r12], #8
+ stcl p1, cr15, [r12], #8
+Lno_iwmmxt:
+
/* Make a tail call to __sigjmp_save; it takes the same args. */
B PLTJMP(C_SYMBOL_NAME(__sigjmp_save))
Index: sysdeps/unix/sysv/linux/arm/dl-procinfo.c
===================================================================
RCS file: /cvs/glibc/ports/sysdeps/unix/sysv/linux/arm/dl-procinfo.c,v
retrieving revision 1.5
diff -u -r1.5 dl-procinfo.c
--- sysdeps/unix/sysv/linux/arm/dl-procinfo.c 22 Jul 2003 22:07:18 -0000 1.5
+++ sysdeps/unix/sysv/linux/arm/dl-procinfo.c 18 Aug 2006 23:12:07 -0000
@@ -1,5 +1,5 @@
/* Data for Linux/ARM version of processor capability information.
- Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Philip Blundell <philb@gnu.org>, 2001.
@@ -47,11 +47,12 @@
#if !defined PROCINFO_DECL && defined SHARED
._dl_arm_cap_flags
#else
-PROCINFO_CLASS const char _dl_arm_cap_flags[8][10]
+PROCINFO_CLASS const char _dl_arm_cap_flags[10][10]
#endif
#ifndef PROCINFO_DECL
= {
"swp", "half", "thumb", "26bit", "fast-mult", "fpa", "vfp", "edsp",
+ "java", "iwmmxt",
}
#endif
#if !defined SHARED || defined PROCINFO_DECL
Index: sysdeps/unix/sysv/linux/arm/dl-procinfo.h
===================================================================
RCS file: /cvs/glibc/ports/sysdeps/unix/sysv/linux/arm/dl-procinfo.h,v
retrieving revision 1.5
diff -u -r1.5 dl-procinfo.h
--- sysdeps/unix/sysv/linux/arm/dl-procinfo.h 7 Mar 2004 08:38:42 -0000 1.5
+++ sysdeps/unix/sysv/linux/arm/dl-procinfo.h 18 Aug 2006 23:12:07 -0000
@@ -1,5 +1,5 @@
/* Linux/ARM version of processor capability information handling macros.
- Copyright (C) 2001, 2002, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2004, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Philip Blundell <philb@gnu.org>, 2001.
@@ -22,8 +22,9 @@
#define _DL_PROCINFO_H 1
#include <ldsodefs.h>
+#include <sysdep.h>
-#define _DL_HWCAP_COUNT 8
+#define _DL_HWCAP_COUNT 10
/* The kernel provides platform data but it is not interesting. */
#define _DL_HWCAP_PLATFORM 0
@@ -53,19 +54,7 @@
return GLRO(dl_arm_cap_flags)[idx];
};
-enum
-{
- HWCAP_ARM_SWP = 1 << 0,
- HWCAP_ARM_HALF = 1 << 1,
- HWCAP_ARM_THUMB = 1 << 2,
- HWCAP_ARM_26BIT = 1 << 3,
- HWCAP_ARM_FAST_MULT = 1 << 4,
- HWCAP_ARM_FPA = 1 << 5,
- HWCAP_ARM_VFP = 1 << 6,
- HWCAP_ARM_EDSP = 1 << 7,
-
- HWCAP_IMPORTANT = (HWCAP_ARM_HALF | HWCAP_ARM_FAST_MULT)
-};
+#define HWCAP_IMPORTANT (HWCAP_ARM_HALF | HWCAP_ARM_FAST_MULT)
static inline int
__attribute__ ((unused))
Index: sysdeps/unix/sysv/linux/arm/sysdep.h
===================================================================
RCS file: /cvs/glibc/ports/sysdeps/unix/sysv/linux/arm/sysdep.h,v
retrieving revision 1.30
diff -u -r1.30 sysdep.h
--- sysdeps/unix/sysv/linux/arm/sysdep.h 28 Feb 2006 19:26:36 -0000 1.30
+++ sysdeps/unix/sysv/linux/arm/sysdep.h 18 Aug 2006 23:12:07 -0000
@@ -37,6 +37,18 @@
#define SYS_ify(syscall_name) (__NR_##syscall_name)
+/* The following must match the kernel's <asm/procinfo.h>. */
+#define HWCAP_ARM_SWP 1
+#define HWCAP_ARM_HALF 2
+#define HWCAP_ARM_THUMB 4
+#define HWCAP_ARM_26BIT 8
+#define HWCAP_ARM_FAST_MULT 16
+#define HWCAP_ARM_FPA 32
+#define HWCAP_ARM_VFP 64
+#define HWCAP_ARM_EDSP 128
+#define HWCAP_ARM_JAVA 256
+#define HWCAP_ARM_IWMMXT 512
+
#ifdef __ASSEMBLER__
/* Linux uses a negative return value to indicate syscall errors,
--
Joseph S. Myers
joseph@codesourcery.com