1/* 2 * linux/arch/alpha/lib/memset.S 3 * 4 * This is an efficient (and small) implementation of the C library "memset()" 5 * function for the alpha. 6 * 7 * (C) Copyright 1996 Linus Torvalds 8 * 9 * This routine is "moral-ware": you are free to use it any way you wish, and 10 * the only obligation I put on you is a moral one: if you make any improvements 11 * to the routine, please send me your improvements for me to use similarly. 12 * 13 * The scheduling comments are according to the EV5 documentation (and done by 14 * hand, so they might well be incorrect, please do tell me about it..) 15 */ 16 17 .set noat 18 .set noreorder 19.text 20 .globl memset 21 .globl __memset 22 .globl __memsetw 23 .globl __constant_c_memset 24 .ent __memset 25.align 5 26__memset: 27 .frame $30,0,$26,0 28 .prologue 0 29 30 and $17,255,$1 /* E1 */ 31 insbl $17,1,$17 /* .. E0 */ 32 bis $17,$1,$17 /* E0 (p-c latency, next cycle) */ 33 sll $17,16,$1 /* E1 (p-c latency, next cycle) */ 34 35 bis $17,$1,$17 /* E0 (p-c latency, next cycle) */ 36 sll $17,32,$1 /* E1 (p-c latency, next cycle) */ 37 bis $17,$1,$17 /* E0 (p-c latency, next cycle) */ 38 ldq_u $31,0($30) /* .. E1 */ 39 40.align 5 41__constant_c_memset: 42 addq $18,$16,$6 /* E0 */ 43 bis $16,$16,$0 /* .. E1 */ 44 xor $16,$6,$1 /* E0 */ 45 ble $18,end /* .. E1 */ 46 47 bic $1,7,$1 /* E0 */ 48 beq $1,within_one_quad /* .. E1 (note EV5 zero-latency forwarding) */ 49 and $16,7,$3 /* E0 */ 50 beq $3,aligned /* .. E1 (note EV5 zero-latency forwarding) */ 51 52 ldq_u $4,0($16) /* E0 */ 53 bis $16,$16,$5 /* .. E1 */ 54 insql $17,$16,$2 /* E0 */ 55 subq $3,8,$3 /* .. E1 */ 56 57 addq $18,$3,$18 /* E0 $18 is new count ($3 is negative) */ 58 mskql $4,$16,$4 /* .. E1 (and possible load stall) */ 59 subq $16,$3,$16 /* E0 $16 is new aligned destination */ 60 bis $2,$4,$1 /* .. E1 */ 61 62 bis $31,$31,$31 /* E0 */ 63 ldq_u $31,0($30) /* .. E1 */ 64 stq_u $1,0($5) /* E0 */ 65 bis $31,$31,$31 /* .. E1 */ 66 67.align 4 68aligned: 69 sra $18,3,$3 /* E0 */ 70 and $18,7,$18 /* .. E1 */ 71 bis $16,$16,$5 /* E0 */ 72 beq $3,no_quad /* .. E1 */ 73 74.align 3 75loop: 76 stq $17,0($5) /* E0 */ 77 subq $3,1,$3 /* .. E1 */ 78 addq $5,8,$5 /* E0 */ 79 bne $3,loop /* .. E1 */ 80 81no_quad: 82 bis $31,$31,$31 /* E0 */ 83 beq $18,end /* .. E1 */ 84 ldq $7,0($5) /* E0 */ 85 mskqh $7,$6,$2 /* .. E1 (and load stall) */ 86 87 insqh $17,$6,$4 /* E0 */ 88 bis $2,$4,$1 /* .. E1 */ 89 stq $1,0($5) /* E0 */ 90 ret $31,($26),1 /* .. E1 */ 91 92.align 3 93within_one_quad: 94 ldq_u $1,0($16) /* E0 */ 95 insql $17,$16,$2 /* E1 */ 96 mskql $1,$16,$4 /* E0 (after load stall) */ 97 bis $2,$4,$2 /* E0 */ 98 99 mskql $2,$6,$4 /* E0 */ 100 mskqh $1,$6,$2 /* .. E1 */ 101 bis $2,$4,$1 /* E0 */ 102 stq_u $1,0($16) /* E0 */ 103 104end: 105 ret $31,($26),1 /* E1 */ 106 .end __memset 107 108 .align 5 109 .ent __memsetw 110__memsetw: 111 .prologue 0 112 113 inswl $17,0,$1 /* E0 */ 114 inswl $17,2,$2 /* E0 */ 115 inswl $17,4,$3 /* E0 */ 116 or $1,$2,$1 /* .. E1 */ 117 inswl $17,6,$4 /* E0 */ 118 or $1,$3,$1 /* .. E1 */ 119 or $1,$4,$17 /* E0 */ 120 br __constant_c_memset /* .. E1 */ 121 122 .end __memsetw 123 124memset = __memset 125