arch/x86/lib/string.c - uboot-imx - Git at Google

 /*
  * Copyright (C) 1991,1992,1993,1997,1998,2003, 2005 Free Software Foundation, Inc.
  * This file is part of the GNU C Library.
  * Copyright (c) 2011 The Chromium OS Authors.
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 /* From glibc-2.14, sysdeps/i386/memset.c */

 #include <linux/types.h>
 #include <linux/compiler.h>
 #include <asm/string.h>

 typedef uint32_t op_t;

 void *memset(void *dstpp, int c, size_t len)
 {
 	int d0;
 	unsigned long int dstp = (unsigned long int) dstpp;

 	/* This explicit register allocation improves code very much indeed. */
 	register op_t x asm("ax");

 	x = (unsigned char) c;

 	/* Clear the direction flag, so filling will move forward.  */
 	asm volatile("cld");

 	/* This threshold value is optimal.  */
 	if (len >= 12) {
 		/* Fill X with four copies of the char we want to fill with. */
 		x |= (x << 8);
 		x |= (x << 16);

 		/* Adjust LEN for the bytes handled in the first loop.  */
 		len -= (-dstp) % sizeof(op_t);

 		/*
 		 * There are at least some bytes to set. No need to test for
 		 * LEN == 0 in this alignment loop.
 		 */

 		/* Fill bytes until DSTP is aligned on a longword boundary. */
 		asm volatile(
 			"rep\n"
 			"stosb" /* %0, %2, %3 */ :
 			"=D" (dstp), "=c" (d0) :
 			"0" (dstp), "1" ((-dstp) % sizeof(op_t)), "a" (x) :
 			"memory");

 		/* Fill longwords.  */
 		asm volatile(
 			"rep\n"
 			"stosl" /* %0, %2, %3 */ :
 			"=D" (dstp), "=c" (d0) :
 			"0" (dstp), "1" (len / sizeof(op_t)), "a" (x) :
 			"memory");
 		len %= sizeof(op_t);
 	}

 	/* Write the last few bytes. */
 	asm volatile(
 		"rep\n"
 		"stosb" /* %0, %2, %3 */ :
 		"=D" (dstp), "=c" (d0) :
 		"0" (dstp), "1" (len), "a" (x) :
 		"memory");

 	return dstpp;
 }

 #define	OP_T_THRES	8
 #define OPSIZ	(sizeof(op_t))

 #define BYTE_COPY_FWD(dst_bp, src_bp, nbytes)				  \
 do {									  \
 	int __d0;							  \
 	asm volatile(							  \
 		/* Clear the direction flag, so copying goes forward.  */ \
 		"cld\n"							  \
 		/* Copy bytes.  */					  \
 		"rep\n"							  \
 		"movsb" :						  \
 		"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) :		  \
 		"0" (dst_bp), "1" (src_bp), "2" (nbytes) :		  \
 		"memory");						  \
 } while (0)

 #define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)		  \
 do {									  \
 	int __d0;							  \
 	asm volatile(							  \
 		/* Clear the direction flag, so copying goes forward.  */ \
 		"cld\n"							  \
 		/* Copy longwords.  */					  \
 		"rep\n"							  \
 		"movsl" :						  \
 		"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) :		  \
 		"0" (dst_bp), "1" (src_bp), "2" ((nbytes) / 4) :	  \
 		"memory");						  \
 	(nbytes_left) = (nbytes) % 4;					  \
 } while (0)

 void *memcpy(void *dstpp, const void *srcpp, size_t len)
 {
 	unsigned long int dstp = (long int)dstpp;
 	unsigned long int srcp = (long int)srcpp;

 	/* Copy from the beginning to the end.  */

 	/* If there not too few bytes to copy, use word copy.  */
 	if (len >= OP_T_THRES) {
 		/* Copy just a few bytes to make DSTP aligned.  */
 		len -= (-dstp) % OPSIZ;
 		BYTE_COPY_FWD(dstp, srcp, (-dstp) % OPSIZ);

 		/* Copy from SRCP to DSTP taking advantage of the known
 		 * alignment of DSTP.  Number of bytes remaining is put
 		 * in the third argument, i.e. in LEN.  This number may
 		 * vary from machine to machine.
 		 */
 		WORD_COPY_FWD(dstp, srcp, len, len);

 		/* Fall out and copy the tail.  */
 	}

 	/* There are just a few bytes to copy. Use byte memory operations. */
 	BYTE_COPY_FWD(dstp, srcp, len);

 	return dstpp;
 }

 void *memmove(void *dest, const void *src, size_t n)
 {
 	int d0, d1, d2, d3, d4, d5;
 	char *ret = dest;

 	__asm__ __volatile__(
 		/* Handle more 16 bytes in loop */
 		"cmp $0x10, %0\n\t"
 		"jb	1f\n\t"

 		/* Decide forward/backward copy mode */
 		"cmp %2, %1\n\t"
 		"jb	2f\n\t"

 		/*
 		 * movs instruction have many startup latency
 		 * so we handle small size by general register.
 		 */
 		"cmp  $680, %0\n\t"
 		"jb 3f\n\t"
 		/* movs instruction is only good for aligned case */
 		"mov %1, %3\n\t"
 		"xor %2, %3\n\t"
 		"and $0xff, %3\n\t"
 		"jz 4f\n\t"
 		"3:\n\t"
 		"sub $0x10, %0\n\t"

 		/* We gobble 16 bytes forward in each loop */
 		"3:\n\t"
 		"sub $0x10, %0\n\t"
 		"mov 0*4(%1), %3\n\t"
 		"mov 1*4(%1), %4\n\t"
 		"mov  %3, 0*4(%2)\n\t"
 		"mov  %4, 1*4(%2)\n\t"
 		"mov 2*4(%1), %3\n\t"
 		"mov 3*4(%1), %4\n\t"
 		"mov  %3, 2*4(%2)\n\t"
 		"mov  %4, 3*4(%2)\n\t"
 		"lea  0x10(%1), %1\n\t"
 		"lea  0x10(%2), %2\n\t"
 		"jae 3b\n\t"
 		"add $0x10, %0\n\t"
 		"jmp 1f\n\t"

 		/* Handle data forward by movs */
 		".p2align 4\n\t"
 		"4:\n\t"
 		"mov -4(%1, %0), %3\n\t"
 		"lea -4(%2, %0), %4\n\t"
 		"shr $2, %0\n\t"
 		"rep movsl\n\t"
 		"mov %3, (%4)\n\t"
 		"jmp 11f\n\t"
 		/* Handle data backward by movs */
 		".p2align 4\n\t"
 		"6:\n\t"
 		"mov (%1), %3\n\t"
 		"mov %2, %4\n\t"
 		"lea -4(%1, %0), %1\n\t"
 		"lea -4(%2, %0), %2\n\t"
 		"shr $2, %0\n\t"
 		"std\n\t"
 		"rep movsl\n\t"
 		"mov %3,(%4)\n\t"
 		"cld\n\t"
 		"jmp 11f\n\t"

 		/* Start to prepare for backward copy */
 		".p2align 4\n\t"
 		"2:\n\t"
 		"cmp  $680, %0\n\t"
 		"jb 5f\n\t"
 		"mov %1, %3\n\t"
 		"xor %2, %3\n\t"
 		"and $0xff, %3\n\t"
 		"jz 6b\n\t"

 		/* Calculate copy position to tail */
 		"5:\n\t"
 		"add %0, %1\n\t"
 		"add %0, %2\n\t"
 		"sub $0x10, %0\n\t"

 		/* We gobble 16 bytes backward in each loop */
 		"7:\n\t"
 		"sub $0x10, %0\n\t"

 		"mov -1*4(%1), %3\n\t"
 		"mov -2*4(%1), %4\n\t"
 		"mov  %3, -1*4(%2)\n\t"
 		"mov  %4, -2*4(%2)\n\t"
 		"mov -3*4(%1), %3\n\t"
 		"mov -4*4(%1), %4\n\t"
 		"mov  %3, -3*4(%2)\n\t"
 		"mov  %4, -4*4(%2)\n\t"
 		"lea  -0x10(%1), %1\n\t"
 		"lea  -0x10(%2), %2\n\t"
 		"jae 7b\n\t"
 		/* Calculate copy position to head */
 		"add $0x10, %0\n\t"
 		"sub %0, %1\n\t"
 		"sub %0, %2\n\t"

 		/* Move data from 8 bytes to 15 bytes */
 		".p2align 4\n\t"
 		"1:\n\t"
 		"cmp $8, %0\n\t"
 		"jb 8f\n\t"
 		"mov 0*4(%1), %3\n\t"
 		"mov 1*4(%1), %4\n\t"
 		"mov -2*4(%1, %0), %5\n\t"
 		"mov -1*4(%1, %0), %1\n\t"

 		"mov  %3, 0*4(%2)\n\t"
 		"mov  %4, 1*4(%2)\n\t"
 		"mov  %5, -2*4(%2, %0)\n\t"
 		"mov  %1, -1*4(%2, %0)\n\t"
 		"jmp 11f\n\t"

 		/* Move data from 4 bytes to 7 bytes */
 		".p2align 4\n\t"
 		"8:\n\t"
 		"cmp $4, %0\n\t"
 		"jb 9f\n\t"
 		"mov 0*4(%1), %3\n\t"
 		"mov -1*4(%1, %0), %4\n\t"
 		"mov  %3, 0*4(%2)\n\t"
 		"mov  %4, -1*4(%2, %0)\n\t"
 		"jmp 11f\n\t"

 		/* Move data from 2 bytes to 3 bytes */
 		".p2align 4\n\t"
 		"9:\n\t"
 		"cmp $2, %0\n\t"
 		"jb 10f\n\t"
 		"movw 0*2(%1), %%dx\n\t"
 		"movw -1*2(%1, %0), %%bx\n\t"
 		"movw %%dx, 0*2(%2)\n\t"
 		"movw %%bx, -1*2(%2, %0)\n\t"
 		"jmp 11f\n\t"

 		/* Move data for 1 byte */
 		".p2align 4\n\t"
 		"10:\n\t"
 		"cmp $1, %0\n\t"
 		"jb 11f\n\t"
 		"movb (%1), %%cl\n\t"
 		"movb %%cl, (%2)\n\t"
 		".p2align 4\n\t"
 		"11:"
 		: "=&c" (d0), "=&S" (d1), "=&D" (d2),
 		  "=r" (d3), "=r" (d4), "=r"(d5)
 		: "0" (n),
 		 "1" (src),
 		 "2" (dest)
 		: "memory");

 	return ret;
 }
	/*
	* Copyright (C) 1991,1992,1993,1997,1998,2003, 2005 Free Software Foundation, Inc.
	* This file is part of the GNU C Library.
	* Copyright (c) 2011 The Chromium OS Authors.
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	/* From glibc-2.14, sysdeps/i386/memset.c */

	#include <linux/types.h>
	#include <linux/compiler.h>
	#include <asm/string.h>

	typedef uint32_t op_t;

	void memset(void dstpp, int c, size_t len)
	{
	int d0;
	unsigned long int dstp = (unsigned long int) dstpp;

	/* This explicit register allocation improves code very much indeed. */
	register op_t x asm("ax");

	x = (unsigned char) c;

	/* Clear the direction flag, so filling will move forward. */
	asm volatile("cld");

	/* This threshold value is optimal. */
	if (len >= 12) {
	/* Fill X with four copies of the char we want to fill with. */
	x \|= (x << 8);
	x \|= (x << 16);

	/* Adjust LEN for the bytes handled in the first loop. */
	len -= (-dstp) % sizeof(op_t);

	/*
	* There are at least some bytes to set. No need to test for
	* LEN == 0 in this alignment loop.
	*/

	/* Fill bytes until DSTP is aligned on a longword boundary. */
	asm volatile(
	"rep\n"
	"stosb" /* %0, %2, %3 */ :
	"=D" (dstp), "=c" (d0) :
	"0" (dstp), "1" ((-dstp) % sizeof(op_t)), "a" (x) :
	"memory");

	/* Fill longwords. */
	asm volatile(
	"rep\n"
	"stosl" /* %0, %2, %3 */ :
	"=D" (dstp), "=c" (d0) :
	"0" (dstp), "1" (len / sizeof(op_t)), "a" (x) :
	"memory");
	len %= sizeof(op_t);
	}

	/* Write the last few bytes. */
	asm volatile(
	"rep\n"
	"stosb" /* %0, %2, %3 */ :
	"=D" (dstp), "=c" (d0) :
	"0" (dstp), "1" (len), "a" (x) :
	"memory");

	return dstpp;
	}

	#define OP_T_THRES 8
	#define OPSIZ (sizeof(op_t))

	#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \
	do { \
	int __d0; \
	asm volatile( \
	/* Clear the direction flag, so copying goes forward. */ \
	"cld\n" \
	/* Copy bytes. */ \
	"rep\n" \
	"movsb" : \
	"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
	"0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
	"memory"); \
	} while (0)

	#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
	do { \
	int __d0; \
	asm volatile( \
	/* Clear the direction flag, so copying goes forward. */ \
	"cld\n" \
	/* Copy longwords. */ \
	"rep\n" \
	"movsl" : \
	"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
	"0" (dst_bp), "1" (src_bp), "2" ((nbytes) / 4) : \
	"memory"); \
	(nbytes_left) = (nbytes) % 4; \
	} while (0)

	void memcpy(void dstpp, const void *srcpp, size_t len)
	{
	unsigned long int dstp = (long int)dstpp;
	unsigned long int srcp = (long int)srcpp;

	/* Copy from the beginning to the end. */

	/* If there not too few bytes to copy, use word copy. */
	if (len >= OP_T_THRES) {
	/* Copy just a few bytes to make DSTP aligned. */
	len -= (-dstp) % OPSIZ;
	BYTE_COPY_FWD(dstp, srcp, (-dstp) % OPSIZ);

	/* Copy from SRCP to DSTP taking advantage of the known
	* alignment of DSTP. Number of bytes remaining is put
	* in the third argument, i.e. in LEN. This number may
	* vary from machine to machine.
	*/
	WORD_COPY_FWD(dstp, srcp, len, len);

	/* Fall out and copy the tail. */
	}

	/* There are just a few bytes to copy. Use byte memory operations. */
	BYTE_COPY_FWD(dstp, srcp, len);

	return dstpp;
	}

	void memmove(void dest, const void *src, size_t n)
	{
	int d0, d1, d2, d3, d4, d5;
	char *ret = dest;

	__asm__ __volatile__(
	/* Handle more 16 bytes in loop */
	"cmp $0x10, %0\n\t"
	"jb 1f\n\t"

	/* Decide forward/backward copy mode */
	"cmp %2, %1\n\t"
	"jb 2f\n\t"

	/*
	* movs instruction have many startup latency
	* so we handle small size by general register.
	*/
	"cmp $680, %0\n\t"
	"jb 3f\n\t"
	/* movs instruction is only good for aligned case */
	"mov %1, %3\n\t"
	"xor %2, %3\n\t"
	"and $0xff, %3\n\t"
	"jz 4f\n\t"
	"3:\n\t"
	"sub $0x10, %0\n\t"

	/* We gobble 16 bytes forward in each loop */
	"3:\n\t"
	"sub $0x10, %0\n\t"
	"mov 0*4(%1), %3\n\t"
	"mov 1*4(%1), %4\n\t"
	"mov %3, 0*4(%2)\n\t"
	"mov %4, 1*4(%2)\n\t"
	"mov 2*4(%1), %3\n\t"
	"mov 3*4(%1), %4\n\t"
	"mov %3, 2*4(%2)\n\t"
	"mov %4, 3*4(%2)\n\t"
	"lea 0x10(%1), %1\n\t"
	"lea 0x10(%2), %2\n\t"
	"jae 3b\n\t"
	"add $0x10, %0\n\t"
	"jmp 1f\n\t"

	/* Handle data forward by movs */
	".p2align 4\n\t"
	"4:\n\t"
	"mov -4(%1, %0), %3\n\t"
	"lea -4(%2, %0), %4\n\t"
	"shr $2, %0\n\t"
	"rep movsl\n\t"
	"mov %3, (%4)\n\t"
	"jmp 11f\n\t"
	/* Handle data backward by movs */
	".p2align 4\n\t"
	"6:\n\t"
	"mov (%1), %3\n\t"
	"mov %2, %4\n\t"
	"lea -4(%1, %0), %1\n\t"
	"lea -4(%2, %0), %2\n\t"
	"shr $2, %0\n\t"
	"std\n\t"
	"rep movsl\n\t"
	"mov %3,(%4)\n\t"
	"cld\n\t"
	"jmp 11f\n\t"

	/* Start to prepare for backward copy */
	".p2align 4\n\t"
	"2:\n\t"
	"cmp $680, %0\n\t"
	"jb 5f\n\t"
	"mov %1, %3\n\t"
	"xor %2, %3\n\t"
	"and $0xff, %3\n\t"
	"jz 6b\n\t"

	/* Calculate copy position to tail */
	"5:\n\t"
	"add %0, %1\n\t"
	"add %0, %2\n\t"
	"sub $0x10, %0\n\t"

	/* We gobble 16 bytes backward in each loop */
	"7:\n\t"
	"sub $0x10, %0\n\t"

	"mov -1*4(%1), %3\n\t"
	"mov -2*4(%1), %4\n\t"
	"mov %3, -1*4(%2)\n\t"
	"mov %4, -2*4(%2)\n\t"
	"mov -3*4(%1), %3\n\t"
	"mov -4*4(%1), %4\n\t"
	"mov %3, -3*4(%2)\n\t"
	"mov %4, -4*4(%2)\n\t"
	"lea -0x10(%1), %1\n\t"
	"lea -0x10(%2), %2\n\t"
	"jae 7b\n\t"
	/* Calculate copy position to head */
	"add $0x10, %0\n\t"
	"sub %0, %1\n\t"
	"sub %0, %2\n\t"

	/* Move data from 8 bytes to 15 bytes */
	".p2align 4\n\t"
	"1:\n\t"
	"cmp $8, %0\n\t"
	"jb 8f\n\t"
	"mov 0*4(%1), %3\n\t"
	"mov 1*4(%1), %4\n\t"
	"mov -2*4(%1, %0), %5\n\t"
	"mov -1*4(%1, %0), %1\n\t"

	"mov %3, 0*4(%2)\n\t"
	"mov %4, 1*4(%2)\n\t"
	"mov %5, -2*4(%2, %0)\n\t"
	"mov %1, -1*4(%2, %0)\n\t"
	"jmp 11f\n\t"

	/* Move data from 4 bytes to 7 bytes */
	".p2align 4\n\t"
	"8:\n\t"
	"cmp $4, %0\n\t"
	"jb 9f\n\t"
	"mov 0*4(%1), %3\n\t"
	"mov -1*4(%1, %0), %4\n\t"
	"mov %3, 0*4(%2)\n\t"
	"mov %4, -1*4(%2, %0)\n\t"
	"jmp 11f\n\t"

	/* Move data from 2 bytes to 3 bytes */
	".p2align 4\n\t"
	"9:\n\t"
	"cmp $2, %0\n\t"
	"jb 10f\n\t"
	"movw 0*2(%1), %%dx\n\t"
	"movw -1*2(%1, %0), %%bx\n\t"
	"movw %%dx, 0*2(%2)\n\t"
	"movw %%bx, -1*2(%2, %0)\n\t"
	"jmp 11f\n\t"

	/* Move data for 1 byte */
	".p2align 4\n\t"
	"10:\n\t"
	"cmp $1, %0\n\t"
	"jb 11f\n\t"
	"movb (%1), %%cl\n\t"
	"movb %%cl, (%2)\n\t"
	".p2align 4\n\t"
	"11:"
	: "=&c" (d0), "=&S" (d1), "=&D" (d2),
	"=r" (d3), "=r" (d4), "=r"(d5)
	: "0" (n),
	"1" (src),
	"2" (dest)
	: "memory");

	return ret;
	}