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/*
 * linux/arch/alpha/memset.S
 *
 * This is an efficient (and small) implementation of the C library "memset()"
 * function for the alpha.
 *
 *      (C) Copyright 1996 Linus Torvalds
 *
 * This routine is "moral-ware": you are free to use it any way you wish, and
 * the only obligation I put on you is a moral one: if you make any improvements
 * to the routine, please send me your improvements for me to use similarly.
 *
 * The scheduling comments are according to the EV5 documentation (and done by 
 * hand, so they might well be incorrect, please do tell me about it..)
 */

        .set noat
        .set noreorder
.text
        .globl __memset
        .globl __constant_c_memset
        .ent __memset
.align 5
__memset:
        .frame $30,0,$26,0
        .prologue 0

        zapnot $17,1,$17        /* E0 */
        sll $17,8,$1            /* E1 (p-c latency, next cycle) */
        bis $17,$1,$17          /* E0 (p-c latency, next cycle) */
        sll $17,16,$1           /* E1 (p-c latency, next cycle) */

        bis $17,$1,$17          /* E0 (p-c latency, next cycle) */
        sll $17,32,$1           /* E1 (p-c latency, next cycle) */
        bis $17,$1,$17          /* E0 (p-c latency, next cycle) */
        ldq_u $31,0($30)        /* .. E1 */

.align 5
__constant_c_memset:
        addq $18,$16,$6         /* E0 */
        bis $16,$16,$0          /* .. E1 */
        xor $16,$6,$1           /* E0 */
        ble $18,end             /* .. E1 */

        bic $1,7,$1             /* E0 */
        beq $1,within_one_quad  /* .. E1 (note EV5 zero-latency forwarding) */
        and $16,7,$3            /* E0 */
        beq $3,aligned          /* .. E1 (note EV5 zero-latency forwarding) */

        ldq_u $4,0($16)         /* E0 */
        bis $16,$16,$5          /* .. E1 */
        insql $17,$16,$2        /* E0 */
        subq $3,8,$3            /* .. E1 */

        addq $18,$3,$18         /* E0           $18 is new count ($3 is negative) */
        mskql $4,$16,$4         /* .. E1 (and possible load stall) */
        subq $16,$3,$16         /* E0           $16 is new aligned destination */
        bis $2,$4,$1            /* .. E1 */

        bis $31,$31,$31         /* E0 */
        ldq_u $31,0($30)        /* .. E1 */
        stq_u $1,0($5)          /* E0 */
        bis $31,$31,$31         /* .. E1 */

.align 4
aligned:
        sra $18,3,$3            /* E0 */
        and $18,7,$18           /* .. E1 */
        bis $16,$16,$5          /* E0 */
        beq $3,no_quad          /* .. E1 */

.align 3
loop:
        stq $17,0($5)           /* E0 */
        subq $3,1,$3            /* .. E1 */
        addq $5,8,$5            /* E0 */
        bne $3,loop             /* .. E1 */

no_quad:
        bis $31,$31,$31         /* E0 */
        beq $18,end             /* .. E1 */
        ldq $7,0($5)            /* E0 */
        mskqh $7,$6,$2          /* .. E1 (and load stall) */

        insqh $17,$6,$4         /* E0 */
        bis $2,$4,$1            /* .. E1 */
        stq $1,0($5)            /* E0 */
        ret $31,($26),1         /* .. E1 */

.align 3
within_one_quad:
        ldq_u $1,0($16)         /* E0 */
        insql $17,$16,$2        /* E1 */
        mskql $1,$16,$4         /* E0 (after load stall) */
        bis $2,$4,$2            /* E0 */

        mskql $2,$6,$4          /* E0 */
        mskqh $1,$6,$2          /* .. E1 */
        bis $2,$4,$1            /* E0 */
        stq_u $1,0($16)         /* E0 */

end:
        ret $31,($26),1         /* E1 */
        .end __memset

#ifdef __ELF__
 .weak memset; memset = __memset
#else
 .weakext memset, __memset
#endif