CoCalc -- findbit.S

GitHub Repository: awilliam/linux-vfio
Path: blob/master/arch/avr32/lib/findbit.S
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/*
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 * Copyright (C) 2006 Atmel Corporation
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 */
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#include <linux/linkage.h>
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	.text
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	/*
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	 * unsigned long find_first_zero_bit(const unsigned long *addr,
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	 *				     unsigned long size)
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	 */
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ENTRY(find_first_zero_bit)
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	cp.w	r11, 0
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	reteq	r11
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	mov	r9, r11
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1:	ld.w	r8, r12[0]
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	com	r8
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	brne	.L_found
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	sub	r12, -4
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	sub	r9, 32
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	brgt	1b
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	retal	r11
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	/*
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	 * unsigned long find_next_zero_bit(const unsigned long *addr,
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	 *				    unsigned long size,
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	 *				    unsigned long offset)
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	 */
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ENTRY(find_next_zero_bit)
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	lsr	r8, r10, 5
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	sub	r9, r11, r10
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	retle	r11
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	lsl	r8, 2
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	add	r12, r8
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	andl	r10, 31, COH
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	breq	1f
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	/* offset is not word-aligned. Handle the first (32 - r10) bits */
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	ld.w	r8, r12[0]
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	com	r8
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	sub	r12, -4
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	lsr	r8, r8, r10
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	brne	.L_found
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	/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
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	add	r9, r10
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	sub	r9, 32
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	retle	r11
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	/* Main loop. offset must be word-aligned */
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1:	ld.w	r8, r12[0]
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	com	r8
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	brne	.L_found
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	sub	r12, -4
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	sub	r9, 32
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	brgt	1b
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	retal	r11
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	/* Common return path for when a bit is actually found. */
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.L_found:
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	brev	r8
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	clz	r10, r8
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	rsub	r9, r11
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	add	r10, r9
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	/* XXX: If we don't have to return exactly "size" when the bit
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	   is not found, we may drop this "min" thing */
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	min	r12, r11, r10
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	retal	r12
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	/*
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	 * unsigned long find_first_bit(const unsigned long *addr,
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	 *				unsigned long size)
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	 */
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ENTRY(find_first_bit)
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	cp.w	r11, 0
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	reteq	r11
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	mov	r9, r11
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1:	ld.w	r8, r12[0]
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	cp.w	r8, 0
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	brne	.L_found
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	sub	r12, -4
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	sub	r9, 32
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	brgt	1b
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	retal	r11
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	/*
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	 * unsigned long find_next_bit(const unsigned long *addr,
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	 *			       unsigned long size,
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	 *			       unsigned long offset)
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	 */
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ENTRY(find_next_bit)
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	lsr	r8, r10, 5
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	sub	r9, r11, r10
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	retle	r11
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	lsl	r8, 2
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	add	r12, r8
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	andl	r10, 31, COH
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	breq	1f
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	/* offset is not word-aligned. Handle the first (32 - r10) bits */
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	ld.w	r8, r12[0]
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	sub	r12, -4
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	lsr	r8, r8, r10
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	brne	.L_found
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	/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
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	add	r9, r10
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	sub	r9, 32
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	retle	r11
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	/* Main loop. offset must be word-aligned */
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1:	ld.w	r8, r12[0]
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	cp.w	r8, 0
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	brne	.L_found
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	sub	r12, -4
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	sub	r9, 32
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	brgt	1b
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	retal	r11
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ENTRY(find_next_bit_le)
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	lsr	r8, r10, 5
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	sub	r9, r11, r10
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	retle	r11
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	lsl	r8, 2
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	add	r12, r8
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	andl	r10, 31, COH
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	breq	1f
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	/* offset is not word-aligned. Handle the first (32 - r10) bits */
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	ldswp.w	r8, r12[0]
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	sub	r12, -4
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	lsr	r8, r8, r10
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	brne	.L_found
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	/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
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	add	r9, r10
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	sub	r9, 32
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	retle	r11
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	/* Main loop. offset must be word-aligned */
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1:	ldswp.w	r8, r12[0]
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	cp.w	r8, 0
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	brne	.L_found
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	sub	r12, -4
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	sub	r9, 32
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	brgt	1b
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	retal	r11
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ENTRY(find_next_zero_bit_le)
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	lsr	r8, r10, 5
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	sub	r9, r11, r10
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	retle	r11
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	lsl	r8, 2
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	add	r12, r8
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	andl	r10, 31, COH
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	breq	1f
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	/* offset is not word-aligned. Handle the first (32 - r10) bits */
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	ldswp.w	r8, r12[0]
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	sub	r12, -4
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	com	r8
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	lsr	r8, r8, r10
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	brne	.L_found
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	/* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
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	add	r9, r10
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	sub	r9, 32
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	retle	r11
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	/* Main loop. offset must be word-aligned */
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1:	ldswp.w	r8, r12[0]
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	com	r8
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	brne	.L_found
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	sub	r12, -4
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	sub	r9, 32
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	brgt	1b
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	retal	r11
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