C6X: library code

Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <[e-mail]>

Signed-off-by: Aurelien Jacquiot <[e-mail]>
Signed-off-by: Mark Salter <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>

arch/c6x/include/asm/checksum.h

···
+/*
+ *  Copyright (C) 2011 Texas Instruments Incorporated
+ *  Author: Mark Salter <[e-mail]>
+ *
+ *  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.
+ */
+#ifndef _ASM_C6X_CHECKSUM_H
+#define _ASM_C6X_CHECKSUM_H
+
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+		   unsigned short proto, __wsum sum)
+{
+	unsigned long long tmp;
+
+	asm ("add     .d1   %1,%5,%1\n"
+	     "|| addu .l1   %3,%4,%0\n"
+	     "addu    .l1   %2,%0,%0\n"
+#ifndef CONFIG_CPU_BIG_ENDIAN
+	     "|| shl  .s1   %1,8,%1\n"
+#endif
+	     "addu    .l1   %1,%0,%0\n"
+	     "add     .l1   %P0,%p0,%2\n"
+	     : "=&a"(tmp), "+a"(len), "+a"(sum)
+	     : "a" (saddr), "a" (daddr), "a" (proto));
+	return sum;
+}
+#define csum_tcpudp_nofold csum_tcpudp_nofold
+
+#include <asm-generic/checksum.h>
+
+#endif /* _ASM_C6X_CHECKSUM_H */

arch/c6x/lib/checksum.c

···
+/*
+ *		This program 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 of the License, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <net/checksum.h>
+
+#include <asm/byteorder.h>
+
+/*
+ * copy from fs while checksumming, otherwise like csum_partial
+ */
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst, int len,
+			    __wsum sum, int *csum_err)
+{
+	int missing;
+
+	missing = __copy_from_user(dst, src, len);
+	if (missing) {
+		memset(dst + len - missing, 0, missing);
+		*csum_err = -EFAULT;
+	} else
+		*csum_err = 0;
+
+	return csum_partial(dst, len, sum);
+}
+EXPORT_SYMBOL(csum_partial_copy_from_user);
+
+/* These are from csum_64plus.S */
+EXPORT_SYMBOL(csum_partial);
+EXPORT_SYMBOL(csum_partial_copy);
+EXPORT_SYMBOL(ip_compute_csum);
+EXPORT_SYMBOL(ip_fast_csum);

arch/c6x/lib/csum_64plus.S

···
+;
+;  linux/arch/c6x/lib/csum_64plus.s
+;
+;  Port on Texas Instruments TMS320C6x architecture
+;
+;  Copyright (C) 2006, 2009, 2010, 2011 Texas Instruments Incorporated
+;  Author: Aurelien Jacquiot ([e-mail])
+;
+;  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>
+
+;
+;unsigned int csum_partial_copy(const char *src, char * dst,
+;				int len, int sum)
+;
+; A4:	src
+; B4:	dst
+; A6:	len
+; B6:	sum
+; return csum in A4
+;
+
+	.text
+ENTRY(csum_partial_copy)
+	MVC	.S2	ILC,B30
+
+	MV	.D1X	B6,A31		; given csum
+	ZERO	.D1	A9		; csum (a side)
+||	ZERO	.D2	B9		; csum (b side)
+||	SHRU	.S2X	A6,2,B5		; len / 4
+
+	;; Check alignment and size
+	AND	.S1	3,A4,A1
+||	AND	.S2	3,B4,B0
+	OR	.L2X	B0,A1,B0	; non aligned condition
+||	MVC	.S2	B5,ILC
+||	MVK	.D2	1,B2
+||	MV	.D1X	B5,A1		; words condition
+  [!A1]	B	.S1	L8
+   [B0] BNOP	.S1	L6,5
+
+	SPLOOP		1
+
+	;; Main loop for aligned words
+	LDW	.D1T1	*A4++,A7
+	NOP	4
+	MV	.S2X	A7,B7
+||	EXTU	.S1	A7,0,16,A16
+	STW	.D2T2	B7,*B4++
+||	MPYU	.M2	B7,B2,B8
+||	ADD	.L1	A16,A9,A9
+	NOP
+	SPKERNEL	8,0
+||	ADD	.L2	B8,B9,B9
+
+	ZERO	.D1	A1
+||	ADD	.L1X	A9,B9,A9	;  add csum from a and b sides
+
+L6:
+  [!A1]	BNOP	.S1	L8,5
+
+	;; Main loop for non-aligned words
+	SPLOOP		2
+ ||	MVK	.L1	1,A2
+
+	LDNW	.D1T1	*A4++,A7
+	NOP		3
+
+	NOP
+	MV	.S2X	A7,B7
+ ||	EXTU	.S1	A7,0,16,A16
+ ||	MPYU	.M1	A7,A2,A8
+
+	ADD	.L1	A16,A9,A9
+	SPKERNEL	6,0
+ ||	STNW	.D2T2	B7,*B4++
+ ||	ADD	.L1	A8,A9,A9
+
+L8:	AND	.S2X	2,A6,B5
+	CMPGT	.L2	B5,0,B0
+  [!B0]	BNOP	.S1	L82,4
+
+	;; Manage half-word
+	ZERO	.L1	A7
+||	ZERO	.D1	A8
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+
+	LDBU	.D1T1	*A4++,A7
+	LDBU	.D1T1	*A4++,A8
+	NOP		3
+	SHL	.S1	A7,8,A0
+	ADD	.S1	A8,A9,A9
+	STB	.D2T1	A7,*B4++
+||	ADD	.S1	A0,A9,A9
+	STB	.D2T1	A8,*B4++
+
+#else
+
+	LDBU	.D1T1	*A4++,A7
+	LDBU	.D1T1	*A4++,A8
+	NOP		3
+	ADD	.S1	A7,A9,A9
+	SHL	.S1	A8,8,A0
+
+	STB	.D2T1	A7,*B4++
+||	ADD	.S1	A0,A9,A9
+	STB	.D2T1	A8,*B4++
+
+#endif
+
+	;; Manage eventually the last byte
+L82:	AND	.S2X	1,A6,B0
+  [!B0]	BNOP	.S1	L9,5
+
+||	ZERO	.L1	A7
+
+L83:	LDBU	.D1T1	*A4++,A7
+	NOP		4
+
+	MV	.L2X	A7,B7
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+
+	STB	.D2T2	B7,*B4++
+||	SHL	.S1	A7,8,A7
+	ADD	.S1	A7,A9,A9
+
+#else
+
+	STB	.D2T2	B7,*B4++
+||	ADD	.S1	A7,A9,A9
+
+#endif
+
+	;; Fold the csum
+L9:	SHRU	.S2X	A9,16,B0
+  [!B0]	BNOP	.S1	L10,5
+
+L91:	SHRU	.S2X	A9,16,B4
+||	EXTU	.S1	A9,16,16,A3
+	ADD	.D1X	A3,B4,A9
+
+	SHRU	.S1	A9,16,A0
+   [A0]	BNOP	.S1	L91,5
+
+L10:	ADD	.D1	A31,A9,A9
+	MV	.D1	A9,A4
+
+	BNOP	.S2	B3,4
+	MVC	.S2	B30,ILC
+ENDPROC(csum_partial_copy)
+
+;
+;unsigned short
+;ip_fast_csum(unsigned char *iph, unsigned int ihl)
+;{
+;	unsigned int checksum = 0;
+;	unsigned short *tosum = (unsigned short *) iph;
+;	int len;
+;
+;	len = ihl*4;
+;
+;	if (len <= 0)
+;		return 0;
+;
+;	while(len) {
+;		len -= 2;
+;		checksum += *tosum++;
+;	}
+;	if (len & 1)
+;		checksum += *(unsigned char*) tosum;
+;
+;	while(checksum >> 16)
+;		checksum = (checksum & 0xffff) + (checksum >> 16);
+;
+;	return ~checksum;
+;}
+;
+; A4:	iph
+; B4:	ihl
+; return checksum in A4
+;
+	.text
+
+ENTRY(ip_fast_csum)
+	ZERO	.D1	A5
+ ||	MVC	.S2	ILC,B30
+	SHL	.S2	B4,2,B0
+	CMPGT	.L2	B0,0,B1
+  [!B1] BNOP	.S1	L15,4
+  [!B1]	ZERO	.D1	A3
+
+  [!B0]	B	.S1	L12
+	SHRU	.S2	B0,1,B0
+	MVC	.S2	B0,ILC
+	NOP	3
+
+	SPLOOP	1
+	LDHU	.D1T1	*A4++,A3
+	NOP	3
+	NOP
+	SPKERNEL	5,0
+ ||	ADD	.L1	A3,A5,A5
+
+L12:	SHRU	.S1	A5,16,A0
+  [!A0]	BNOP	.S1	L14,5
+
+L13:	SHRU	.S2X	A5,16,B4
+	EXTU	.S1	A5,16,16,A3
+	ADD	.D1X	A3,B4,A5
+	SHRU	.S1	A5,16,A0
+  [A0]	BNOP	.S1	L13,5
+
+L14:	NOT	.D1	A5,A3
+	EXTU	.S1	A3,16,16,A3
+
+L15:	BNOP	.S2	B3,3
+	MVC	.S2	B30,ILC
+	MV	.D1	A3,A4
+ENDPROC(ip_fast_csum)
+
+;
+;unsigned short
+;do_csum(unsigned char *buff, unsigned int len)
+;{
+;	int odd, count;
+;	unsigned int result = 0;
+;
+;	if (len <= 0)
+;		goto out;
+;	odd = 1 & (unsigned long) buff;
+;	if (odd) {
+;#ifdef __LITTLE_ENDIAN
+;		result += (*buff << 8);
+;#else
+;		result = *buff;
+;#endif
+;		len--;
+;		buff++;
+;	}
+;	count = len >> 1;		/* nr of 16-bit words.. */
+;	if (count) {
+;		if (2 & (unsigned long) buff) {
+;			result += *(unsigned short *) buff;
+;			count--;
+;			len -= 2;
+;			buff += 2;
+;		}
+;		count >>= 1;		/* nr of 32-bit words.. */
+;		if (count) {
+;			unsigned int carry = 0;
+;			do {
+;				unsigned int w = *(unsigned int *) buff;
+;				count--;
+;				buff += 4;
+;				result += carry;
+;				result += w;
+;				carry = (w > result);
+;			} while (count);
+;			result += carry;
+;			result = (result & 0xffff) + (result >> 16);
+;		}
+;		if (len & 2) {
+;			result += *(unsigned short *) buff;
+;			buff += 2;
+;		}
+;	}
+;	if (len & 1)
+;#ifdef __LITTLE_ENDIAN
+;		result += *buff;
+;#else
+;		result += (*buff << 8);
+;#endif
+;	result = (result & 0xffff) + (result >> 16);
+;	/* add up carry.. */
+;	result = (result & 0xffff) + (result >> 16);
+;	if (odd)
+;		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+;out:
+;	return result;
+;}
+;
+; A4:	buff
+; B4:	len
+; return checksum in A4
+;
+
+ENTRY(do_csum)
+	   CMPGT   .L2	   B4,0,B0
+   [!B0]   BNOP    .S1	   L26,3
+	   EXTU    .S1	   A4,31,31,A0
+
+	   MV	   .L1	   A0,A3
+||	   MV	   .S1X    B3,A5
+||	   MV	   .L2	   B4,B3
+||	   ZERO    .D1	   A1
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+   [A0]    SUB	   .L2	   B3,1,B3
+|| [A0]    LDBU    .D1T1   *A4++,A1
+#else
+   [!A0]   BNOP    .S1	   L21,5
+|| [A0]    LDBU    .D1T1   *A4++,A0
+	   SUB	   .L2	   B3,1,B3
+||	   SHL	   .S1	   A0,8,A1
+L21:
+#endif
+	   SHR	   .S2	   B3,1,B0
+   [!B0]   BNOP    .S1	   L24,3
+	   MVK	   .L1	   2,A0
+	   AND	   .L1	   A4,A0,A0
+
+   [!A0]   BNOP    .S1	   L22,5
+|| [A0]    LDHU    .D1T1   *A4++,A0
+	   SUB	   .L2	   B0,1,B0
+||	   SUB	   .S2	   B3,2,B3
+||	   ADD	   .L1	   A0,A1,A1
+L22:
+	   SHR	   .S2	   B0,1,B0
+||	   ZERO    .L1	   A0
+
+   [!B0]   BNOP    .S1	   L23,5
+|| [B0]    MVC	   .S2	   B0,ILC
+
+	   SPLOOP  3
+	   SPMASK  L1
+||	   MV	   .L1	   A1,A2
+||	   LDW	   .D1T1   *A4++,A1
+
+	   NOP	   4
+	   ADD	   .L1	   A0,A1,A0
+	   ADD	   .L1	   A2,A0,A2
+
+	   SPKERNEL 1,2
+||	   CMPGTU  .L1	   A1,A2,A0
+
+	   ADD	   .L1	   A0,A2,A6
+	   EXTU    .S1	   A6,16,16,A7
+	   SHRU    .S2X    A6,16,B0
+	   NOP		   1
+	   ADD	   .L1X    A7,B0,A1
+L23:
+	   MVK	   .L2	   2,B0
+	   AND	   .L2	   B3,B0,B0
+   [B0]    LDHU    .D1T1   *A4++,A0
+	   NOP	   4
+   [B0]    ADD	   .L1	   A0,A1,A1
+L24:
+	   EXTU    .S2	   B3,31,31,B0
+#ifdef CONFIG_CPU_BIG_ENDIAN
+   [!B0]   BNOP    .S1	   L25,4
+|| [B0]    LDBU    .D1T1   *A4,A0
+	   SHL	   .S1	   A0,8,A0
+	   ADD	   .L1	   A0,A1,A1
+L25:
+#else
+   [B0]    LDBU    .D1T1   *A4,A0
+	   NOP	   4
+   [B0]    ADD	   .L1	   A0,A1,A1
+#endif
+	   EXTU    .S1	   A1,16,16,A0
+	   SHRU    .S2X    A1,16,B0
+	   NOP	   1
+	   ADD	   .L1X    A0,B0,A0
+	   SHRU    .S1	   A0,16,A1
+	   ADD	   .L1	   A0,A1,A0
+	   EXTU    .S1	   A0,16,16,A1
+	   EXTU    .S1	   A1,16,24,A2
+
+	   EXTU    .S1	   A1,24,16,A0
+||	   MV	   .L2X    A3,B0
+
+   [B0]    OR	   .L1	   A0,A2,A1
+L26:
+	   NOP	   1
+	   BNOP    .S2X    A5,4
+	   MV	   .L1	   A1,A4
+ENDPROC(do_csum)
+
+;__wsum csum_partial(const void *buff, int len, __wsum wsum)
+;{
+;	unsigned int sum = (__force unsigned int)wsum;
+;	unsigned int result = do_csum(buff, len);
+;
+;	/* add in old sum, and carry.. */
+;	result += sum;
+;	if (sum > result)
+;		result += 1;
+;	return (__force __wsum)result;
+;}
+;
+ENTRY(csum_partial)
+	   MV	   .L1X    B3,A9
+||	   CALLP   .S2	   do_csum,B3
+||	   MV	   .S1	   A6,A8
+	   BNOP    .S2X    A9,2
+	   ADD	   .L1	   A8,A4,A1
+	   CMPGTU  .L1	   A8,A1,A0
+	   ADD	   .L1	   A1,A0,A4
+ENDPROC(csum_partial)
+
+;unsigned short
+;ip_compute_csum(unsigned char *buff, unsigned int len)
+;
+; A4:	buff
+; B4:	len
+; return checksum in A4
+
+ENTRY(ip_compute_csum)
+	   MV	   .L1X    B3,A9
+||	   CALLP   .S2	   do_csum,B3
+	   BNOP    .S2X    A9,3
+	   NOT	   .S1	   A4,A4
+	   CLR     .S1	   A4,16,31,A4
+ENDPROC(ip_compute_csum)

arch/c6x/lib/divi.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	;; ABI considerations for the divide functions
+	;; The following registers are call-used:
+	;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
+	;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
+	;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
+	;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
+	;;
+	;; In our implementation, divu and remu are leaf functions,
+	;; while both divi and remi call into divu.
+	;; A0 is not clobbered by any of the functions.
+	;; divu does not clobber B2 either, which is taken advantage of
+	;; in remi.
+	;; divi uses B5 to hold the original return address during
+	;; the call to divu.
+	;; remi uses B2 and A5 to hold the input values during the
+	;; call to divu.  It stores B3 in on the stack.
+
+	.text
+ENTRY(__c6xabi_divi)
+	call	.s2	__c6xabi_divu
+||	mv	.d2	B3, B5
+||	cmpgt	.l1	0, A4, A1
+||	cmpgt	.l2	0, B4, B1
+
+   [A1]	neg	.l1	A4, A4
+|| [B1]	neg	.l2	B4, B4
+||	xor	.s1x	A1, B1, A1
+   [A1] addkpc	.s2	_divu_ret, B3, 4
+_divu_ret:
+	neg	.l1	A4, A4
+||	mv	.l2	B3,B5
+||	ret	.s2	B5
+	nop		5
+ENDPROC(__c6xabi_divi)

arch/c6x/lib/divremi.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(__c6xabi_divremi)
+	stw	.d2t2	B3, *B15--[2]
+||	cmpgt	.l1	0, A4, A1
+||	cmpgt	.l2	0, B4, B2
+||	mv	.s1	A4, A5
+||	call	.s2	__c6xabi_divu
+
+   [A1]	neg	.l1	A4, A4
+|| [B2]	neg	.l2	B4, B4
+||	xor	.s2x	B2, A1, B0
+||	mv	.d2	B4, B2
+
+   [B0]	addkpc	.s2	_divu_ret_1, B3, 1
+  [!B0] addkpc	.s2	_divu_ret_2, B3, 1
+	nop	2
+_divu_ret_1:
+	neg	.l1	A4, A4
+_divu_ret_2:
+	ldw	.d2t2	*++B15[2], B3
+
+	mpy32	.m1x	A4, B2, A6
+	nop		3
+	ret	.s2	B3
+	sub	.l1	A5, A6, A5
+	nop	4
+ENDPROC(__c6xabi_divremi)

arch/c6x/lib/divremu.S

···
+;;  Copyright 2011  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(__c6xabi_divremu)
+	;; We use a series of up to 31 subc instructions.  First, we find
+	;; out how many leading zero bits there are in the divisor.  This
+	;; gives us both a shift count for aligning (shifting) the divisor
+	;; to the, and the number of times we have to execute subc.
+
+	;; At the end, we have both the remainder and most of the quotient
+	;; in A4.  The top bit of the quotient is computed first and is
+	;; placed in A2.
+
+	;; Return immediately if the dividend is zero.	Setting B4 to 1
+	;; is a trick to allow us to leave the following insns in the jump
+	;; delay slot without affecting the result.
+	mv	.s2x	A4, B1
+
+  [b1]	lmbd	.l2	1, B4, B1
+||[!b1] b	.s2	B3	; RETURN A
+||[!b1] mvk	.d2	1, B4
+
+||[!b1] zero	.s1	A5
+	mv	.l1x	B1, A6
+||	shl	.s2	B4, B1, B4
+
+	;; The loop performs a maximum of 28 steps, so we do the
+	;; first 3 here.
+	cmpltu	.l1x	A4, B4, A2
+  [!A2]	sub	.l1x	A4, B4, A4
+||	shru	.s2	B4, 1, B4
+||	xor	.s1	1, A2, A2
+
+	shl	.s1	A2, 31, A2
+|| [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+
+	;; RETURN A may happen here (note: must happen before the next branch)
+__divremu0:
+	cmpgt	.l2	B1, 7, B0
+|| [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+|| [b0] b	.s1	__divremu0
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+   [b1]	subc	.l1x	A4,B4,A4
+|| [b1]	add	.s2	-1, B1, B1
+	;; loop backwards branch happens here
+
+	ret	.s2	B3
+||	mvk	.s1	32, A1
+	sub	.l1	A1, A6, A6
+||	extu	.s1	A4, A6, A5
+	shl	.s1	A4, A6, A4
+	shru	.s1	A4, 1, A4
+||	sub	.l1	A6, 1, A6
+	or	.l1	A2, A4, A4
+	shru	.s1	A4, A6, A4
+	nop
+ENDPROC(__c6xabi_divremu)

arch/c6x/lib/divu.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	;; ABI considerations for the divide functions
+	;; The following registers are call-used:
+	;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
+	;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
+	;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
+	;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
+	;;
+	;; In our implementation, divu and remu are leaf functions,
+	;; while both divi and remi call into divu.
+	;; A0 is not clobbered by any of the functions.
+	;; divu does not clobber B2 either, which is taken advantage of
+	;; in remi.
+	;; divi uses B5 to hold the original return address during
+	;; the call to divu.
+	;; remi uses B2 and A5 to hold the input values during the
+	;; call to divu.  It stores B3 in on the stack.
+
+	.text
+ENTRY(__c6xabi_divu)
+	;; We use a series of up to 31 subc instructions.  First, we find
+	;; out how many leading zero bits there are in the divisor.  This
+	;; gives us both a shift count for aligning (shifting) the divisor
+	;; to the, and the number of times we have to execute subc.
+
+	;; At the end, we have both the remainder and most of the quotient
+	;; in A4.  The top bit of the quotient is computed first and is
+	;; placed in A2.
+
+	;; Return immediately if the dividend is zero.
+	 mv	.s2x	A4, B1
+   [B1]	 lmbd	.l2	1, B4, B1
+|| [!B1] b	.s2	B3	; RETURN A
+|| [!B1] mvk	.d2	1, B4
+	 mv	.l1x	B1, A6
+||	 shl	.s2	B4, B1, B4
+
+	;; The loop performs a maximum of 28 steps, so we do the
+	;; first 3 here.
+	 cmpltu	.l1x	A4, B4, A2
+   [!A2] sub	.l1x	A4, B4, A4
+||	 shru	.s2	B4, 1, B4
+||	 xor	.s1	1, A2, A2
+
+	 shl	.s1	A2, 31, A2
+|| [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+
+	;; RETURN A may happen here (note: must happen before the next branch)
+_divu_loop:
+	 cmpgt	.l2	B1, 7, B0
+|| [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+|| [B0]  b	.s1	_divu_loop
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+	;; loop backwards branch happens here
+
+	 ret	.s2	B3
+||	 mvk	.s1	32, A1
+	 sub	.l1	A1, A6, A6
+	 shl	.s1	A4, A6, A4
+	 shru	.s1	A4, 1, A4
+||	 sub	.l1	A6, 1, A6
+	 or	.l1	A2, A4, A4
+	 shru	.s1	A4, A6, A4
+	 nop
+ENDPROC(__c6xabi_divu)

arch/c6x/lib/llshl.S

···
+;;  Copyright (C) 2010 Texas Instruments Incorporated
+;;  Contributed by Mark Salter <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+;;  uint64_t __c6xabi_llshl(uint64_t val, uint shift)
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(__c6xabi_llshl)
+	 mv	.l1x	B4,A1
+   [!A1] b	.s2	B3		; just return if zero shift
+	 mvk	.s1	32,A0
+	 sub	.d1	A0,A1,A0
+	 cmplt	.l1	0,A0,A2
+   [A2]	 shru	.s1	A4,A0,A0
+   [!A2] neg	.l1	A0,A5
+|| [A2]  shl	.s1	A5,A1,A5
+   [!A2] shl	.s1	A4,A5,A5
+|| [A2]  or	.d1	A5,A0,A5
+|| [!A2] mvk	.l1	0,A4
+   [A2]	 shl	.s1	A4,A1,A4
+	 bnop	.s2	B3,5
+ENDPROC(__c6xabi_llshl)

arch/c6x/lib/llshr.S

···
+;;  Copyright (C) 2010 Texas Instruments Incorporated
+;;  Contributed by Mark Salter <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+;;  uint64_t __c6xabi_llshr(uint64_t val, uint shift)
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(__c6xabi_llshr)
+	 mv	.l1x	B4,A1
+   [!A1] b	.s2	B3		; return if zero shift count
+	 mvk	.s1	32,A0
+	 sub	.d1	A0,A1,A0
+	 cmplt	.l1	0,A0,A2
+   [A2]  shl	.s1	A5,A0,A0
+	 nop
+   [!A2] neg	.l1	A0,A4
+|| [A2]  shru	.s1	A4,A1,A4
+   [!A2] shr	.s1	A5,A4,A4
+|| [A2]  or	.d1	A4,A0,A4
+   [!A2] shr	.s1	A5,0x1f,A5
+   [A2]  shr	.s1	A5,A1,A5
+	 bnop	.s2	B3,5
+ENDPROC(__c6xabi_llshr)

arch/c6x/lib/llshru.S

···
+;;  Copyright (C) 2010 Texas Instruments Incorporated
+;;  Contributed by Mark Salter <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+;;  uint64_t __c6xabi_llshru(uint64_t val, uint shift)
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(__c6xabi_llshru)
+	 mv	.l1x	B4,A1
+   [!A1] b	.s2	B3		; return if zero shift count
+	 mvk	.s1	32,A0
+	 sub	.d1	A0,A1,A0
+	 cmplt	.l1	0,A0,A2
+   [A2]  shl	.s1	A5,A0,A0
+	 nop
+   [!A2] neg	.l1	A0,A4
+|| [A2]  shru	.s1	A4,A1,A4
+   [!A2] shru	.s1	A5,A4,A4
+|| [A2]  or	.d1	A4,A0,A4
+|| [!A2] mvk	.l1	0,A5
+   [A2]  shru	.s1	A5,A1,A5
+	 bnop	.s2	B3,5
+ENDPROC(__c6xabi_llshru)

arch/c6x/lib/memcpy_64plus.S

···
+;  Port on Texas Instruments TMS320C6x architecture
+;
+;  Copyright (C) 2006, 2009, 2010 Texas Instruments Incorporated
+;  Author: Aurelien Jacquiot ([e-mail])
+;
+;  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>
+
+	.text
+
+ENTRY(memcpy)
+	AND	.L1	0x1,A6,A0
+ ||	AND	.S1	0x2,A6,A1
+ ||	AND	.L2X	0x4,A6,B0
+ ||	MV	.D1	A4,A3
+ ||	MVC	.S2	ILC,B2
+
+   [A0] LDB	.D2T1	*B4++,A5
+   [A1] LDB	.D2T1	*B4++,A7
+   [A1] LDB	.D2T1	*B4++,A8
+   [B0] LDNW	.D2T1	*B4++,A9
+ ||	SHRU	.S2X	A6,0x3,B1
+  [!B1] BNOP	.S2	B3,1
+
+   [A0] STB	.D1T1	A5,*A3++
+ ||[B1] MVC	.S2	B1,ILC
+   [A1] STB	.D1T1	A7,*A3++
+   [A1] STB	.D1T1	A8,*A3++
+   [B0] STNW	.D1T1	A9,*A3++	; return when len < 8
+
+	SPLOOP	2
+
+	LDNDW	.D2T1	*B4++,A9:A8
+	NOP	3
+
+	NOP
+	SPKERNEL	0,0
+ ||	STNDW	.D1T1	A9:A8,*A3++
+
+	BNOP	.S2	B3,4
+	MVC	.S2	B2,ILC
+ENDPROC(memcpy)

arch/c6x/lib/mpyll.S

···
+;;  Copyright (C) 2010 Texas Instruments Incorporated
+;;  Contributed by Mark Salter <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	;; uint64_t __c6xabi_mpyll(uint64_t x, uint64_t y)
+	;;
+	;; 64x64 multiply
+	;; First compute partial results using 32-bit parts of x and y:
+	;;
+	;;   b63	 b32 b31	  b0
+	;;    -----------------------------
+	;;    |      1	    |	   0	  |
+	;;    -----------------------------
+	;;
+	;;   P0 = X0*Y0
+	;;   P1 = X0*Y1 + X1*Y0
+	;;   P2 = X1*Y1
+	;;
+	;;   result = (P2 << 64) + (P1 << 32) + P0
+	;;
+	;; Since the result is also 64-bit, we can skip the P2 term.
+
+	.text
+ENTRY(__c6xabi_mpyll)
+	mpy32u	.m1x	A4,B4,A1:A0	; X0*Y0
+	b	.s2	B3
+ ||	mpy32u	.m2x	B5,A4,B1:B0	; X0*Y1 (don't need upper 32-bits)
+ ||	mpy32u	.m1x	A5,B4,A3:A2	; X1*Y0 (don't need upper 32-bits)
+	nop
+	nop
+	mv	.s1	A0,A4
+	add	.l1x	A2,B0,A5
+	add	.s1	A1,A5,A5
+ENDPROC(__c6xabi_mpyll)

arch/c6x/lib/negll.S

···
+;;  Copyright (C) 2010 Texas Instruments Incorporated
+;;  Contributed by Mark Salter <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+;;  int64_t __c6xabi_negll(int64_t val)
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(__c6xabi_negll)
+	b	.s2	B3
+	mvk	.l1	0,A0
+	subu	.l1	A0,A4,A3:A2
+	sub	.l1	A0,A5,A0
+||	ext	.s1	A3,24,24,A5
+	add	.l1	A5,A0,A5
+	mv	.s1	A2,A4
+ENDPROC(__c6xabi_negll)

arch/c6x/lib/pop_rts.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	.text
+
+ENTRY(__c6xabi_pop_rts)
+	lddw	.d2t2	*++B15, B3:B2
+	lddw	.d2t1	*++B15, A11:A10
+	lddw	.d2t2	*++B15, B11:B10
+	lddw	.d2t1	*++B15, A13:A12
+	lddw	.d2t2	*++B15, B13:B12
+	lddw	.d2t1	*++B15, A15:A14
+||	b	.s2	B3
+	ldw	.d2t2	*++B15[2], B14
+	nop	4
+ENDPROC(__c6xabi_pop_rts)

arch/c6x/lib/push_rts.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	.text
+
+ENTRY(__c6xabi_push_rts)
+	stw	.d2t2	B14, *B15--[2]
+	stdw	.d2t1	A15:A14, *B15--
+||	b	.s2x	A3
+	stdw	.d2t2	B13:B12, *B15--
+	stdw	.d2t1	A13:A12, *B15--
+	stdw	.d2t2	B11:B10, *B15--
+	stdw	.d2t1	A11:A10, *B15--
+	stdw	.d2t2	B3:B2, *B15--
+ENDPROC(__c6xabi_push_rts)

arch/c6x/lib/remi.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	;; ABI considerations for the divide functions
+	;; The following registers are call-used:
+	;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
+	;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
+	;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
+	;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
+	;;
+	;; In our implementation, divu and remu are leaf functions,
+	;; while both divi and remi call into divu.
+	;; A0 is not clobbered by any of the functions.
+	;; divu does not clobber B2 either, which is taken advantage of
+	;; in remi.
+	;; divi uses B5 to hold the original return address during
+	;; the call to divu.
+	;; remi uses B2 and A5 to hold the input values during the
+	;; call to divu.  It stores B3 in on the stack.
+
+	.text
+
+ENTRY(__c6xabi_remi)
+	stw	.d2t2	B3, *B15--[2]
+||	cmpgt	.l1	0, A4, A1
+||	cmpgt	.l2	0, B4, B2
+||	mv	.s1	A4, A5
+||	call	.s2	__c6xabi_divu
+
+   [A1]	neg	.l1	A4, A4
+|| [B2]	neg	.l2	B4, B4
+||	xor	.s2x	B2, A1, B0
+||	mv	.d2	B4, B2
+
+   [B0]	addkpc	.s2	_divu_ret_1, B3, 1
+  [!B0] addkpc	.s2	_divu_ret_2, B3, 1
+	nop	2
+_divu_ret_1:
+	neg	.l1	A4, A4
+_divu_ret_2:
+	ldw	.d2t2	*++B15[2], B3
+
+	mpy32	.m1x	A4, B2, A6
+	nop		3
+	ret	.s2	B3
+	sub	.l1	A5, A6, A4
+	nop	4
+ENDPROC(__c6xabi_remi)

arch/c6x/lib/remu.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	;; ABI considerations for the divide functions
+	;; The following registers are call-used:
+	;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
+	;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
+	;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
+	;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
+	;;
+	;; In our implementation, divu and remu are leaf functions,
+	;; while both divi and remi call into divu.
+	;; A0 is not clobbered by any of the functions.
+	;; divu does not clobber B2 either, which is taken advantage of
+	;; in remi.
+	;; divi uses B5 to hold the original return address during
+	;; the call to divu.
+	;; remi uses B2 and A5 to hold the input values during the
+	;; call to divu.  It stores B3 in on the stack.
+
+
+	.text
+
+ENTRY(__c6xabi_remu)
+	;; The ABI seems designed to prevent these functions calling each other,
+	;; so we duplicate most of the divsi3 code here.
+	 mv	.s2x	A4, B1
+	 lmbd	.l2	1, B4, B1
+|| [!B1] b	.s2	B3	; RETURN A
+|| [!B1] mvk	.d2	1, B4
+
+	 mv	.l1x	B1, A7
+||	 shl	.s2	B4, B1, B4
+
+	 cmpltu	.l1x	A4, B4, A1
+   [!A1] sub	.l1x	A4, B4, A4
+	 shru	.s2	B4, 1, B4
+
+_remu_loop:
+	 cmpgt	.l2	B1, 7, B0
+|| [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+	;; RETURN A may happen here (note: must happen before the next branch)
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+|| [B0]	 b	.s1	_remu_loop
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+	;; loop backwards branch happens here
+
+	 ret	.s2	B3
+   [B1]	 subc	.l1x	A4,B4,A4
+|| [B1]	 add	.s2	-1, B1, B1
+   [B1]	 subc	.l1x	A4,B4,A4
+
+	 extu	.s1	A4, A7, A4
+	 nop	2
+ENDPROC(__c6xabi_remu)

arch/c6x/lib/strasgi.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	.text
+
+ENTRY(__c6xabi_strasgi)
+	;; This is essentially memcpy, with alignment known to be at least
+	;; 4, and the size a multiple of 4 greater than or equal to 28.
+	 ldw	.d2t1	*B4++, A0
+||	 mvk	.s2	16, B1
+	 ldw	.d2t1	*B4++, A1
+||	 mvk	.s2	20, B2
+||	 sub	.d1	A6, 24, A6
+	 ldw	.d2t1	*B4++, A5
+	 ldw	.d2t1	*B4++, A7
+||	 mv	.l2x	A6, B7
+	 ldw	.d2t1	*B4++, A8
+	 ldw	.d2t1	*B4++, A9
+||	 mv	.s2x	A0, B5
+||	 cmpltu	.l2	B2, B7, B0
+
+_strasgi_loop:
+	 stw	.d1t2	B5, *A4++
+|| [B0]	 ldw	.d2t1	*B4++, A0
+||	 mv	.s2x	A1, B5
+||	 mv	.l2	B7, B6
+
+   [B0]	 sub	.d2	B6, 24, B7
+|| [B0]	 b	.s2	_strasgi_loop
+||	 cmpltu	.l2	B1, B6, B0
+
+   [B0]	 ldw	.d2t1	*B4++, A1
+||	 stw	.d1t2	B5, *A4++
+||	 mv	.s2x	A5, B5
+||	 cmpltu	.l2	12, B6, B0
+
+   [B0]	 ldw	.d2t1	*B4++, A5
+||	 stw	.d1t2	B5, *A4++
+||	 mv	.s2x	A7, B5
+||	 cmpltu	.l2	8, B6, B0
+
+   [B0]	 ldw	.d2t1	*B4++, A7
+||	 stw	.d1t2	B5, *A4++
+||	 mv	.s2x	A8, B5
+||	 cmpltu	.l2	4, B6, B0
+
+   [B0]	 ldw	.d2t1	*B4++, A8
+||	 stw	.d1t2	B5, *A4++
+||	 mv	.s2x	A9, B5
+||	 cmpltu	.l2	0, B6, B0
+
+   [B0]	 ldw	.d2t1	*B4++, A9
+||	 stw	.d1t2	B5, *A4++
+||	 mv	.s2x	A0, B5
+||	 cmpltu	.l2	B2, B7, B0
+
+	;; loop back branch happens here
+
+	 cmpltu	.l2	B1, B6, B0
+||	 ret	.s2	b3
+
+   [B0]	 stw	.d1t1	A1, *A4++
+||	 cmpltu	.l2	12, B6, B0
+   [B0]	 stw	.d1t1	A5, *A4++
+||	 cmpltu	.l2	8, B6, B0
+   [B0]	 stw	.d1t1	A7, *A4++
+||	 cmpltu	.l2	4, B6, B0
+   [B0]	 stw	.d1t1	A8, *A4++
+||	 cmpltu	.l2	0, B6, B0
+   [B0]	 stw	.d1t1	A9, *A4++
+
+	;; return happens here
+ENDPROC(__c6xabi_strasgi)

arch/c6x/lib/strasgi_64plus.S

···
+;;  Copyright 2010  Free Software Foundation, Inc.
+;;  Contributed by Bernd Schmidt <[e-mail]>.
+;;
+;; This program 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 of the License, or
+;; (at your option) any later version.
+;;
+;; This program 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; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include <linux/linkage.h>
+
+	.text
+
+ENTRY(__c6xabi_strasgi_64plus)
+	shru	.s2x	a6, 2, b31
+||	mv	.s1	a4, a30
+||	mv	.d2	b4, b30
+
+	add	.s2	-4, b31, b31
+
+	sploopd		1
+||	mvc	.s2	b31, ilc
+	ldw	.d2t2	*b30++, b31
+	nop	4
+	mv	.s1x	b31,a31
+	spkernel	6, 0
+||	stw	.d1t1	a31, *a30++
+
+	ret	.s2	b3
+	nop 5
+ENDPROC(__c6xabi_strasgi_64plus)