Date: Thu, 15 Nov 2018 20:28:35 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r340464 - head/lib/libc/amd64/string Message-ID: <201811152028.wAFKSZne077132@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: mjg Date: Thu Nov 15 20:28:35 2018 New Revision: 340464 URL: https://svnweb.freebsd.org/changeset/base/340464 Log: amd64: sync up libc memset with the kernel version - tidy up memset to have rax set earlier for small sizes - finish the tail in memset with an overlapping store - align memset buffers to 16 bytes before using rep stos Sponsored by: The FreeBSD Foundation Modified: head/lib/libc/amd64/string/memset.S Modified: head/lib/libc/amd64/string/memset.S ============================================================================== --- head/lib/libc/amd64/string/memset.S Thu Nov 15 20:20:39 2018 (r340463) +++ head/lib/libc/amd64/string/memset.S Thu Nov 15 20:28:35 2018 (r340464) @@ -31,12 +31,14 @@ #include <machine/asm.h> __FBSDID("$FreeBSD$"); +#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */ + .macro MEMSET erms - movq %rdi,%r9 + movq %rdi,%rax movq %rdx,%rcx movzbq %sil,%r8 - movabs $0x0101010101010101,%rax - imulq %r8,%rax + movabs $0x0101010101010101,%r10 + imulq %r8,%r10 cmpq $32,%rcx jb 1016f @@ -45,10 +47,10 @@ __FBSDID("$FreeBSD$"); ja 1256f 1032: - movq %rax,(%rdi) - movq %rax,8(%rdi) - movq %rax,16(%rdi) - movq %rax,24(%rdi) + movq %r10,(%rdi) + movq %r10,8(%rdi) + movq %r10,16(%rdi) + movq %r10,24(%rdi) leaq 32(%rdi),%rdi subq $32,%rcx cmpq $32,%rcx @@ -58,54 +60,72 @@ __FBSDID("$FreeBSD$"); 1016: cmpb $16,%cl jl 1008f - movq %rax,(%rdi) - movq %rax,8(%rdi) + movq %r10,(%rdi) + movq %r10,8(%rdi) subb $16,%cl jz 1000f leaq 16(%rdi),%rdi 1008: cmpb $8,%cl jl 1004f - movq %rax,(%rdi) + movq %r10,(%rdi) subb $8,%cl jz 1000f leaq 8(%rdi),%rdi 1004: cmpb $4,%cl jl 1002f - movl %eax,(%rdi) + movl %r10d,(%rdi) subb $4,%cl jz 1000f leaq 4(%rdi),%rdi 1002: cmpb $2,%cl jl 1001f - movw %ax,(%rdi) + movw %r10w,(%rdi) subb $2,%cl jz 1000f leaq 2(%rdi),%rdi 1001: cmpb $1,%cl jl 1000f - movb %al,(%rdi) + movb %r10b,(%rdi) 1000: - movq %r9,%rax 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 %rdx,%rcx - andb $7,%cl - jne 1004b -.endif 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)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201811152028.wAFKSZne077132>