/* memset/bzero -- set memory area to CH/0 Highly optimized version for ix86, x>=6. Copyright (C) 1999-2013 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 1999. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #include #include "asm-syntax.h" #include "bp-sym.h" #include "bp-asm.h" /* BEWARE: `#ifdef memset' means that memset is redefined as `bzero' */ #define BZERO_P (defined memset) #define PARMS LINKAGE+4 /* space for 1 saved reg */ #if BZERO_P # define DEST PARMS # define LEN DEST+PTR_SIZE #else # define RTN PARMS # define DEST RTN+RTN_SIZE # define CHR DEST+PTR_SIZE # define LEN CHR+4 #endif .text #if defined PIC && !defined NOT_IN_libc && !BZERO_P ENTRY_CHK (__memset_chk) movl 12(%esp), %eax cmpl %eax, 16(%esp) jb HIDDEN_JUMPTARGET (__chk_fail) END_CHK (__memset_chk) #endif ENTRY (BP_SYM (memset)) ENTER cld pushl %edi cfi_adjust_cfa_offset (4) movl DEST(%esp), %edx movl LEN(%esp), %ecx CHECK_BOUNDS_BOTH_WIDE (%edx, DEST(%esp), %ecx) #if BZERO_P xorl %eax, %eax /* fill with 0 */ #else movzbl CHR(%esp), %eax #endif jecxz 1f movl %edx, %edi cfi_rel_offset (edi, 0) andl $3, %edx jz 2f /* aligned */ jp 3f /* misaligned at 3, store just one byte below */ stosb /* misaligned at 1 or 2, store two bytes */ decl %ecx jz 1f 3: stosb decl %ecx jz 1f xorl $1, %edx jnz 2f /* was misaligned at 2 or 3, now aligned */ stosb /* was misaligned at 1, store third byte */ decl %ecx 2: movl %ecx, %edx shrl $2, %ecx andl $3, %edx #if !BZERO_P imul $0x01010101, %eax #endif rep stosl movl %edx, %ecx rep stosb 1: #if !BZERO_P movl DEST(%esp), %eax /* start address of destination is result */ RETURN_BOUNDED_POINTER (DEST(%esp)) #endif popl %edi cfi_adjust_cfa_offset (-4) cfi_restore (edi) LEAVE #if BZERO_P ret #else RET_PTR #endif END (BP_SYM (memset)) libc_hidden_builtin_def (memset) #if defined PIC && !defined NOT_IN_libc && !BZERO_P strong_alias (__memset_chk, __memset_zero_constant_len_parameter) .section .gnu.warning.__memset_zero_constant_len_parameter .string "memset used with constant zero length parameter; this could be due to transposed parameters" #endif