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Diffstat (limited to 'lib/libc/amd64/string/memset.S')
| -rw-r--r-- | lib/libc/amd64/string/memset.S | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/lib/libc/amd64/string/memset.S b/lib/libc/amd64/string/memset.S new file mode 100644 index 000000000000..bfab34eeaeb9 --- /dev/null +++ b/lib/libc/amd64/string/memset.S @@ -0,0 +1,145 @@ +/*- + * Copyright (c) 2018 The FreeBSD Foundation + * + * This software was developed by Mateusz Guzik <mjg@FreeBSD.org> + * under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <machine/asm.h> +/* + * Note: this routine was written with kernel use in mind (read: no simd), + * it is only present in userspace as a temporary measure until something + * better gets imported. + */ + +#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */ + +.macro MEMSET erms + movq %rdi,%rax + movq %rdx,%rcx + movzbq %sil,%r8 + movabs $0x0101010101010101,%r10 + imulq %r8,%r10 + + cmpq $32,%rcx + jbe 101632f + + cmpq $256,%rcx + ja 1256f + + ALIGN_TEXT +103200: + movq %r10,(%rdi) + movq %r10,8(%rdi) + movq %r10,16(%rdi) + movq %r10,24(%rdi) + leaq 32(%rdi),%rdi + subq $32,%rcx + cmpq $32,%rcx + ja 103200b + cmpb $16,%cl + ja 201632f + movq %r10,-16(%rdi,%rcx) + movq %r10,-8(%rdi,%rcx) + ret + ALIGN_TEXT +101632: + cmpb $16,%cl + jl 100816f +201632: + movq %r10,(%rdi) + movq %r10,8(%rdi) + movq %r10,-16(%rdi,%rcx) + movq %r10,-8(%rdi,%rcx) + ret + ALIGN_TEXT +100816: + cmpb $8,%cl + jl 100408f + movq %r10,(%rdi) + movq %r10,-8(%rdi,%rcx) + ret + ALIGN_TEXT +100408: + cmpb $4,%cl + jl 100204f + movl %r10d,(%rdi) + movl %r10d,-4(%rdi,%rcx) + ret + ALIGN_TEXT +100204: + cmpb $2,%cl + jl 100001f + movw %r10w,(%rdi) + movw %r10w,-2(%rdi,%rcx) + ret + ALIGN_TEXT +100001: + cmpb $0,%cl + je 100000f + movb %r10b,(%rdi) +100000: + ret + ALIGN_TEXT +1256: + movq %rdi,%r9 + movq %r10,%rax + testl $15,%edi + jnz 3f +1: +.if \erms == 1 + rep + stosb + movq %r9,%rax +.else + movq %rcx,%rdx + shrq $3,%rcx + rep + stosq + movq %r9,%rax + andl $7,%edx + jnz 2f + ret +2: + movq %r10,-8(%rdi,%rdx) +.endif + ret + ALIGN_TEXT +3: + movq %r10,(%rdi) + movq %r10,8(%rdi) + movq %rdi,%r8 + andq $15,%r8 + leaq -16(%rcx,%r8),%rcx + neg %r8 + leaq 16(%rdi,%r8),%rdi + jmp 1b +.endm + + +ENTRY(memset) + MEMSET erms=0 +END(memset) + + .section .note.GNU-stack,"",%progbits |