10Sstevel@tonic-gate/* 20Sstevel@tonic-gate * CDDL HEADER START 30Sstevel@tonic-gate * 40Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7298SMark.J.Nelson@Sun.COM * Common Development and Distribution License (the "License"). 6*7298SMark.J.Nelson@Sun.COM * You may not use this file except in compliance with the License. 70Sstevel@tonic-gate * 80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 100Sstevel@tonic-gate * See the License for the specific language governing permissions 110Sstevel@tonic-gate * and limitations under the License. 120Sstevel@tonic-gate * 130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 170Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 180Sstevel@tonic-gate * 190Sstevel@tonic-gate * CDDL HEADER END 200Sstevel@tonic-gate */ 210Sstevel@tonic-gate/* 220Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 230Sstevel@tonic-gate * Use is subject to license terms. 240Sstevel@tonic-gate */ 250Sstevel@tonic-gate 26*7298SMark.J.Nelson@Sun.COM .file "strcat.s" 270Sstevel@tonic-gate 280Sstevel@tonic-gate/ 290Sstevel@tonic-gate/ strcat(s1, s2) 300Sstevel@tonic-gate/ 310Sstevel@tonic-gate/ Concatenates s2 on the end of s1. s1's space must be large enough. 320Sstevel@tonic-gate/ Returns s1. 330Sstevel@tonic-gate/ 340Sstevel@tonic-gate/ Fast assembly language version of the following C-program strcat 350Sstevel@tonic-gate/ which represents the `standard' for the C-library. 360Sstevel@tonic-gate/ 370Sstevel@tonic-gate/ char * 380Sstevel@tonic-gate/ strcat(char *s1, const char *s2) 390Sstevel@tonic-gate/ { 400Sstevel@tonic-gate/ char *os1 = s1; 410Sstevel@tonic-gate/ 420Sstevel@tonic-gate/ while (*s1++) 430Sstevel@tonic-gate/ ; 440Sstevel@tonic-gate/ --s1; 450Sstevel@tonic-gate/ while (*s1++ = *s2++) 460Sstevel@tonic-gate/ ; 470Sstevel@tonic-gate/ return (os1); 480Sstevel@tonic-gate/ } 490Sstevel@tonic-gate/ 500Sstevel@tonic-gate/ In this assembly language version, the following expression is used 510Sstevel@tonic-gate/ to check if a 32-bit word data contains a null byte or not: 520Sstevel@tonic-gate/ (((A & 0x7f7f7f7f) + 0x7f7f7f7f) | A) & 0x80808080 530Sstevel@tonic-gate/ If the above expression geneates a value other than 0x80808080, 540Sstevel@tonic-gate/ that means the 32-bit word data contains a null byte. 550Sstevel@tonic-gate/ 560Sstevel@tonic-gate/ The above has been extended for 64-bit support. 570Sstevel@tonic-gate/ 580Sstevel@tonic-gate 590Sstevel@tonic-gate#include "SYS.h" 600Sstevel@tonic-gate 610Sstevel@tonic-gate ENTRY(strcat) /* (char *s1, char *s2) */ 620Sstevel@tonic-gate / find a null byte in destination string 630Sstevel@tonic-gate movq %rdi,%rax / prepare return value 640Sstevel@tonic-gate movabsq $0x7f7f7f7f7f7f7f7f, %r8 / %r8 = 0x7f... 650Sstevel@tonic-gate movq %r8, %r9 660Sstevel@tonic-gate notq %r9 / %r9 = 0x80... 670Sstevel@tonic-gate testq $7, %rdi / if %rdi not quadword aligned 680Sstevel@tonic-gate jnz .L1 / goto .L1 690Sstevel@tonic-gate .align 4 700Sstevel@tonic-gate.L2: 710Sstevel@tonic-gate movq (%rdi), %rdx / move 1 quadword from (%rdi) to %rdx 720Sstevel@tonic-gate movq %r8, %rcx 730Sstevel@tonic-gate andq %rdx, %rcx / %rcx = %rdx & 0x7f7f7f7f7f7f7f7f 740Sstevel@tonic-gate addq $8, %rdi / next quadword 750Sstevel@tonic-gate addq %r8, %rcx / %rcx += 0x7f7f7f7f7f7f7f7f 760Sstevel@tonic-gate orq %rdx, %rcx / %rcx |= %rdx 770Sstevel@tonic-gate andq %r9, %rcx / %rcx &= 0x8080808080808080 780Sstevel@tonic-gate cmpq %r9, %rcx / if no null byte in this quadword 790Sstevel@tonic-gate je .L2 / goto .L2 800Sstevel@tonic-gate subq $8, %rdi / post-incremented 810Sstevel@tonic-gate.L1: 820Sstevel@tonic-gate cmpb $0, (%rdi) / if a byte in (%rdi) is null 830Sstevel@tonic-gate je .L3 / goto .L3 840Sstevel@tonic-gate incq %rdi / next byte 850Sstevel@tonic-gate testq $7, %rdi / if %rdi not quadword aligned 860Sstevel@tonic-gate jnz .L1 / goto .L1 870Sstevel@tonic-gate jmp .L2 / goto .L2 (%rdi quadword aligned) 880Sstevel@tonic-gate .align 4 890Sstevel@tonic-gate.L3: 900Sstevel@tonic-gate / %rdi points to a null byte in destination string 910Sstevel@tonic-gate testq $7, %rsi / if %rsi not quadword aligned 920Sstevel@tonic-gate jnz .L4 / goto .L4 930Sstevel@tonic-gate .align 4 940Sstevel@tonic-gate.L5: 950Sstevel@tonic-gate movq (%rsi), %rdx / move 1 quadword from (%rsi) to %rdx 960Sstevel@tonic-gate movq %r8, %rcx 970Sstevel@tonic-gate andq %rdx, %rcx / %rcx = %rdx & 0x7f7f7f7f7f7f7f7f 980Sstevel@tonic-gate addq $8, %rsi / next quadword 990Sstevel@tonic-gate addq %r8, %rcx / %rcx += 0x7f7f7f7f7f7f7f7f 1000Sstevel@tonic-gate orq %rdx, %rcx / %rcx |= %rdx 1010Sstevel@tonic-gate andq %r9, %rcx / %rcx &= 0x8080808080808080 1020Sstevel@tonic-gate cmpq %r9, %rcx / if null byte in this quadaword 1030Sstevel@tonic-gate jne .L7 / goto .L7 1040Sstevel@tonic-gate movq %rdx, (%rdi) / copy this quadword to (%rdi) 1050Sstevel@tonic-gate addq $8, %rdi / next quadword 1060Sstevel@tonic-gate jmp .L5 / goto .L5 1070Sstevel@tonic-gate.L7: 1080Sstevel@tonic-gate subq $8, %rsi / post-incremented 1090Sstevel@tonic-gate .align 4 1100Sstevel@tonic-gate.L4: 1110Sstevel@tonic-gate movb (%rsi), %dl / %dl = a byte in (%rsi) 1120Sstevel@tonic-gate cmpb $0, %dl / compare %dl with a null byte 1130Sstevel@tonic-gate movb %dl, (%rdi) / copy %dl to (%rdi) 1140Sstevel@tonic-gate je .L6 / if %dl is a null, goto .L6 1150Sstevel@tonic-gate incq %rsi / next byte 1160Sstevel@tonic-gate incq %rdi / next byte 1170Sstevel@tonic-gate testq $7, %rsi / if %rsi not word aligned 1180Sstevel@tonic-gate jnz .L4 / goto .L4 1190Sstevel@tonic-gate jmp .L5 / goto .L5 (%rsi word aligned) 1200Sstevel@tonic-gate .align 4 1210Sstevel@tonic-gate.L6: 1220Sstevel@tonic-gate ret 1230Sstevel@tonic-gate SET_SIZE(strcat) 124