/* * linux/arch/alpha/lib/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 __memset .globl ___memset .globl __memsetw .globl __constant_c_memset .ent ___memset .align 5 ___memset: .frame $30,0,$26,0 .prologue 0 and $17,255,$1 /* E1 */ insbl $17,1,$17 /* .. E0 */ 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 .align 5 .ent __memsetw __memsetw: .prologue 0 inswl $17,0,$1 /* E0 */ inswl $17,2,$2 /* E0 */ inswl $17,4,$3 /* E0 */ or $1,$2,$1 /* .. E1 */ inswl $17,6,$4 /* E0 */ or $1,$3,$1 /* .. E1 */ or $1,$4,$17 /* E0 */ br __constant_c_memset /* .. E1 */ .end __memsetw memset = ___memset __memset = ___memset