[ARM] 3049/1: More optimized libgcc functions

Patch from Nicolas Pitre

This patch gets rid of the last C implementations of needed libgcc
functions for the kernel, replacing them with optimized assembly
versions.

Those functions are:

__ashldi3
__ashrdi3
__lshrdi3
__muldi3
__ucmpdi2

The first 3 were lifted from gcc, the other two were written from scratch.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

11 files changed, 223 insertions, 312 deletions

diff --git a/arch/arm/lib/ashldi3.S b/arch/arm/lib/ashldi3.S
new file mode 100644
index 0000000..561e207
--- /dev/null
+++ b/arch/arm/lib/ashldi3.S
@@ -0,0 +1,48 @@
+/* Copyright 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005
+   Free Software Foundation, Inc.
+
+This file is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+This file 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
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; see the file COPYING.  If not, write to
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+
+#include <linux/linkage.h>
+
+#ifdef __ARMEB__
+#define al r1
+#define ah r0
+#else
+#define al r0
+#define ah r1
+#endif
+
+ENTRY(__ashldi3)
+
+	subs	r3, r2, #32
+	rsb	ip, r2, #32
+	movmi	ah, ah, lsl r2
+	movpl	ah, al, lsl r3
+	orrmi	ah, ah, al, lsr ip
+	mov	al, al, lsl r2
+	mov	pc, lr
+
diff --git a/arch/arm/lib/ashldi3.c b/arch/arm/lib/ashldi3.c
deleted file mode 100644
index b62875c..0000000
--- a/arch/arm/lib/ashldi3.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/* More subroutines needed by GCC output code on some machines.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
-
-This file is part of GNU CC.
-
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU CC 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 General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
-
-/* As a special exception, if you link this library with other files,
-   some of which are compiled with GCC, to produce an executable,
-   this library does not by itself cause the resulting executable
-   to be covered by the GNU General Public License.
-   This exception does not however invalidate any other reasons why
-   the executable file might be covered by the GNU General Public License.
- */
-/* support functions required by the kernel. based on code from gcc-2.95.3 */
-/* I Molton	29/07/01 */
-
-#include "gcclib.h"
-
-s64 __ashldi3(s64 u, int b)
-{
-	DIunion w;
-	int bm;
-	DIunion uu;
-
-	if (b == 0)
-		return u;
-
-	uu.ll = u;
-
-	bm = (sizeof(s32) * BITS_PER_UNIT) - b;
-	if (bm <= 0) {
-		w.s.low = 0;
-		w.s.high = (u32) uu.s.low << -bm;
-	} else {
-		u32 carries = (u32) uu.s.low >> bm;
-		w.s.low = (u32) uu.s.low << b;
-		w.s.high = ((u32) uu.s.high << b) | carries;
-	}
-
-	return w.ll;
-}
diff --git a/arch/arm/lib/ashrdi3.S b/arch/arm/lib/ashrdi3.S
new file mode 100644
index 0000000..86fb2a9
--- /dev/null
+++ b/arch/arm/lib/ashrdi3.S
@@ -0,0 +1,48 @@
+/* Copyright 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005
+   Free Software Foundation, Inc.
+
+This file is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+This file 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
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; see the file COPYING.  If not, write to
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+
+#include <linux/linkage.h>
+
+#ifdef __ARMEB__
+#define al r1
+#define ah r0
+#else
+#define al r0
+#define ah r1
+#endif
+
+ENTRY(__ashrdi3)
+
+	subs	r3, r2, #32
+	rsb	ip, r2, #32
+	movmi	al, al, lsr r2
+	movpl	al, ah, asr r3
+	orrmi	al, al, ah, lsl ip
+	mov	ah, ah, asr r2
+	mov	pc, lr
+
diff --git a/arch/arm/lib/ashrdi3.c b/arch/arm/lib/ashrdi3.c
deleted file mode 100644
index 9a8600a..0000000
--- a/arch/arm/lib/ashrdi3.c
+++ /dev/null
@@ -1,57 +0,0 @@
-/* More subroutines needed by GCC output code on some machines.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
-
-This file is part of GNU CC.
-
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU CC 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 General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
-
-/* As a special exception, if you link this library with other files,
-   some of which are compiled with GCC, to produce an executable,
-   this library does not by itself cause the resulting executable
-   to be covered by the GNU General Public License.
-   This exception does not however invalidate any other reasons why
-   the executable file might be covered by the GNU General Public License.
- */
-/* support functions required by the kernel. based on code from gcc-2.95.3 */
-/* I Molton     29/07/01 */
-
-#include "gcclib.h"
-
-s64 __ashrdi3(s64 u, int b)
-{
-	DIunion w;
-	int bm;
-	DIunion uu;
-
-	if (b == 0)
-		return u;
-
-	uu.ll = u;
-
-	bm = (sizeof(s32) * BITS_PER_UNIT) - b;
-	if (bm <= 0) {
-		/* w.s.high = 1..1 or 0..0 */
-		w.s.high = uu.s.high >> (sizeof(s32) * BITS_PER_UNIT - 1);
-		w.s.low = uu.s.high >> -bm;
-	} else {
-		u32 carries = (u32) uu.s.high << bm;
-		w.s.high = uu.s.high >> b;
-		w.s.low = ((u32) uu.s.low >> b) | carries;
-	}
-
-	return w.ll;
-}
diff --git a/arch/arm/lib/gcclib.h b/arch/arm/lib/gcclib.h
deleted file mode 100644
index 8b6dcc6..0000000
--- a/arch/arm/lib/gcclib.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* gcclib.h -- definitions for various functions 'borrowed' from gcc-2.95.3 */
-/* I Molton     29/07/01 */
-
-#include <linux/types.h>
-
-#define BITS_PER_UNIT	8
-#define SI_TYPE_SIZE	(sizeof(s32) * BITS_PER_UNIT)
-
-#ifdef __ARMEB__
-struct DIstruct {
-	s32 high, low;
-};
-#else
-struct DIstruct {
-	s32 low, high;
-};
-#endif
-
-typedef union {
-	struct DIstruct s;
-	s64 ll;
-} DIunion;
diff --git a/arch/arm/lib/lshrdi3.S b/arch/arm/lib/lshrdi3.S
new file mode 100644
index 0000000..46c2ed1
--- /dev/null
+++ b/arch/arm/lib/lshrdi3.S
@@ -0,0 +1,48 @@
+/* Copyright 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005
+   Free Software Foundation, Inc.
+
+This file is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+This file 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
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; see the file COPYING.  If not, write to
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+
+#include <linux/linkage.h>
+
+#ifdef __ARMEB__
+#define al r1
+#define ah r0
+#else
+#define al r0
+#define ah r1
+#endif
+
+ENTRY(__lshrdi3)
+
+	subs	r3, r2, #32
+	rsb	ip, r2, #32
+	movmi	al, al, lsr r2
+	movpl	al, ah, lsr r3
+	orrmi	al, al, ah, lsl ip
+	mov	ah, ah, lsr r2
+	mov	pc, lr
+
diff --git a/arch/arm/lib/lshrdi3.c b/arch/arm/lib/lshrdi3.c
deleted file mode 100644
index 3681f49..0000000
--- a/arch/arm/lib/lshrdi3.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/* More subroutines needed by GCC output code on some machines.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
-
-This file is part of GNU CC.
-
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU CC 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 General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
-
-/* As a special exception, if you link this library with other files,
-   some of which are compiled with GCC, to produce an executable,
-   this library does not by itself cause the resulting executable
-   to be covered by the GNU General Public License.
-   This exception does not however invalidate any other reasons why
-   the executable file might be covered by the GNU General Public License.
- */
-/* support functions required by the kernel. based on code from gcc-2.95.3 */
-/* I Molton     29/07/01 */
-
-#include "gcclib.h"
-
-s64 __lshrdi3(s64 u, int b)
-{
-	DIunion w;
-	int bm;
-	DIunion uu;
-
-	if (b == 0)
-		return u;
-
-	uu.ll = u;
-
-	bm = (sizeof(s32) * BITS_PER_UNIT) - b;
-	if (bm <= 0) {
-		w.s.high = 0;
-		w.s.low = (u32) uu.s.high >> -bm;
-	} else {
-		u32 carries = (u32) uu.s.high << bm;
-		w.s.high = (u32) uu.s.high >> b;
-		w.s.low = ((u32) uu.s.low >> b) | carries;
-	}
-
-	return w.ll;
-}
diff --git a/arch/arm/lib/muldi3.S b/arch/arm/lib/muldi3.S
new file mode 100644
index 0000000..c7fbdf0
--- /dev/null
+++ b/arch/arm/lib/muldi3.S
@@ -0,0 +1,44 @@
+/*
+ *  linux/arch/arm/lib/muldi3.S
+ *
+ *  Author:     Nicolas Pitre
+ *  Created:    Oct 19, 2005
+ *  Copyright:  Monta Vista Software, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+#ifdef __ARMEB__
+#define xh r0
+#define xl r1
+#define yh r2
+#define yl r3
+#else
+#define xl r0
+#define xh r1
+#define yl r2
+#define yh r3
+#endif
+
+ENTRY(__muldi3)
+
+	mul	xh, yl, xh
+	mla	xh, xl, yh, xh
+	mov	ip, xl, asr #16
+	mov	yh, yl, asr #16
+	bic	xl, xl, ip, lsl #16
+	bic	yl, yl, yh, lsl #16
+	mla	xh, yh, ip, xh
+	mul	yh, xl, yh
+	mul	xl, yl, xl
+	mul	ip, yl, ip
+	adds	xl, xl, yh, lsl #16
+	adc	xh, xh, yh, lsr #16
+	adds	xl, xl, ip, lsl #16
+	adc	xh, xh, ip, lsr #16
+	mov	pc, lr
+
diff --git a/arch/arm/lib/muldi3.c b/arch/arm/lib/muldi3.c
deleted file mode 100644
index 0a3b933..0000000
--- a/arch/arm/lib/muldi3.c
+++ /dev/null
@@ -1,72 +0,0 @@
-/* More subroutines needed by GCC output code on some machines.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
-
-This file is part of GNU CC.
-
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU CC 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 General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
-
-/* As a special exception, if you link this library with other files,
-   some of which are compiled with GCC, to produce an executable,
-   this library does not by itself cause the resulting executable
-   to be covered by the GNU General Public License.
-   This exception does not however invalidate any other reasons why
-   the executable file might be covered by the GNU General Public License.
- */
-/* support functions required by the kernel. based on code from gcc-2.95.3 */
-/* I Molton     29/07/01 */
-
-#include "gcclib.h"
-
-#define umul_ppmm(xh, xl, a, b) \
-{register u32 __t0, __t1, __t2;                                     \
-  __asm__ ("%@ Inlined umul_ppmm					\n\
-        mov     %2, %5, lsr #16						\n\
-        mov     %0, %6, lsr #16						\n\
-        bic     %3, %5, %2, lsl #16					\n\
-        bic     %4, %6, %0, lsl #16					\n\
-        mul     %1, %3, %4						\n\
-        mul     %4, %2, %4						\n\
-        mul     %3, %0, %3						\n\
-        mul     %0, %2, %0						\n\
-        adds    %3, %4, %3						\n\
-        addcs   %0, %0, #65536						\n\
-        adds    %1, %1, %3, lsl #16					\n\
-        adc     %0, %0, %3, lsr #16"                                    \
-           : "=&r" ((u32) (xh)),                                    \
-             "=r" ((u32) (xl)),                                     \
-             "=&r" (__t0), "=&r" (__t1), "=r" (__t2)                    \
-           : "r" ((u32) (a)),                                       \
-             "r" ((u32) (b)));}
-
-#define __umulsidi3(u, v) \
-  ({DIunion __w;                                                        \
-    umul_ppmm (__w.s.high, __w.s.low, u, v);                            \
-    __w.ll; })
-
-s64 __muldi3(s64 u, s64 v)
-{
-	DIunion w;
-	DIunion uu, vv;
-
-	uu.ll = u, vv.ll = v;
-
-	w.ll = __umulsidi3(uu.s.low, vv.s.low);
-	w.s.high += ((u32) uu.s.low * (u32) vv.s.high
-		     + (u32) uu.s.high * (u32) vv.s.low);
-
-	return w.ll;
-}
diff --git a/arch/arm/lib/ucmpdi2.S b/arch/arm/lib/ucmpdi2.S
new file mode 100644
index 0000000..112630f
--- /dev/null
+++ b/arch/arm/lib/ucmpdi2.S
@@ -0,0 +1,35 @@
+/*
+ *  linux/arch/arm/lib/ucmpdi2.S
+ *
+ *  Author:	Nicolas Pitre
+ *  Created:	Oct 19, 2005
+ *  Copyright:	Monta Vista Software, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+#ifdef __ARMEB__
+#define xh r0
+#define xl r1
+#define yh r2
+#define yl r3
+#else
+#define xl r0
+#define xh r1
+#define yl r2
+#define yh r3
+#endif
+
+ENTRY(__ucmpdi2)
+
+	cmp	xh, yh
+	cmpeq	xl, yl
+	movlo	r0, #0
+	moveq	r0, #1
+	movhi	r0, #2
+	mov	pc, lr
+
diff --git a/arch/arm/lib/ucmpdi2.c b/arch/arm/lib/ucmpdi2.c
deleted file mode 100644
index 57f3f2d..0000000
--- a/arch/arm/lib/ucmpdi2.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/* More subroutines needed by GCC output code on some machines.  */
-/* Compile this one with gcc.  */
-/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
-
-This file is part of GNU CC.
-
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU CC 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 General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING.  If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
-
-/* As a special exception, if you link this library with other files,
-   some of which are compiled with GCC, to produce an executable,
-   this library does not by itself cause the resulting executable
-   to be covered by the GNU General Public License.
-   This exception does not however invalidate any other reasons why
-   the executable file might be covered by the GNU General Public License.
- */
-/* support functions required by the kernel. based on code from gcc-2.95.3 */
-/* I Molton     29/07/01 */
-
-#include "gcclib.h"
-
-int __ucmpdi2(s64 a, s64 b)
-{
-	DIunion au, bu;
-
-	au.ll = a, bu.ll = b;
-
-	if ((u32) au.s.high < (u32) bu.s.high)
-		return 0;
-	else if ((u32) au.s.high > (u32) bu.s.high)
-		return 2;
-	if ((u32) au.s.low < (u32) bu.s.low)
-		return 0;
-	else if ((u32) au.s.low > (u32) bu.s.low)
-		return 2;
-	return 1;
-}