Date: Thu, 30 Jan 2020 19:57:05 +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: r357310 - head/lib/libc/amd64/string Message-ID: <202001301957.00UJv50w004171@repo.freebsd.org>
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Author: mjg Date: Thu Jan 30 19:57:05 2020 New Revision: 357310 URL: https://svnweb.freebsd.org/changeset/base/357310 Log: amd64: sync up libc memcmp with the kernel version (r357309) Modified: head/lib/libc/amd64/string/memcmp.S Modified: head/lib/libc/amd64/string/memcmp.S ============================================================================== --- head/lib/libc/amd64/string/memcmp.S Thu Jan 30 19:56:22 2020 (r357309) +++ head/lib/libc/amd64/string/memcmp.S Thu Jan 30 19:57:05 2020 (r357310) @@ -45,7 +45,7 @@ ENTRY(memcmp) movq (%rdi),%r8 movq (%rsi),%r9 cmpq %r8,%r9 - jne 1f + jne 80f movq -8(%rdi,%rdx),%r8 movq -8(%rsi,%rdx),%r9 cmpq %r8,%r9 @@ -54,34 +54,33 @@ ENTRY(memcmp) 100408: cmpb $4,%dl jl 100204f - movl (%rsi),%r8d - movl (%rdi),%r9d + movl (%rdi),%r8d + movl (%rsi),%r9d cmpl %r8d,%r9d - jne 1f - movl -4(%rsi,%rdx),%r8d - movl -4(%rdi,%rdx),%r9d + jne 80f + movl -4(%rdi,%rdx),%r8d + movl -4(%rsi,%rdx),%r9d cmpl %r8d,%r9d - jne 1f + jne 10040804f ret 100204: cmpb $2,%dl jl 100001f - movzwl (%rsi),%r8d - movzwl (%rdi),%r9d + movzwl (%rdi),%r8d + movzwl (%rsi),%r9d cmpl %r8d,%r9d jne 1f - movzwl -2(%rsi,%rdx),%r8d - movzwl -2(%rdi,%rdx),%r9d + movzwl -2(%rdi,%rdx),%r8d + movzwl -2(%rsi,%rdx),%r9d cmpl %r8d,%r9d jne 1f ret 100001: cmpb $1,%dl jl 100000f - movzbl (%rdi),%r8d - movzbl (%rsi),%r9d - cmpb %r8b,%r9b - jne 1f + movzbl (%rdi),%eax + movzbl (%rsi),%r8d + subl %r8d,%eax 100000: ret ALIGN_TEXT @@ -91,11 +90,11 @@ ALIGN_TEXT movq (%rdi),%r8 movq (%rsi),%r9 cmpq %r8,%r9 - jne 1f + jne 80f movq 8(%rdi),%r8 movq 8(%rsi),%r9 cmpq %r8,%r9 - jne 10163208f + jne 10163208f movq -16(%rdi,%rdx),%r8 movq -16(%rsi,%rdx),%r9 cmpq %r8,%r9 @@ -111,14 +110,14 @@ ALIGN_TEXT movq 8(%rdi),%r9 subq (%rsi),%r8 subq 8(%rsi),%r9 - or %r8,%r9 + orq %r8,%r9 jnz 10320000f movq 16(%rdi),%r8 movq 24(%rdi),%r9 subq 16(%rsi),%r8 subq 24(%rsi),%r9 - or %r8,%r9 + orq %r8,%r9 jnz 10320016f leaq 32(%rdi),%rdi @@ -130,40 +129,57 @@ ALIGN_TEXT jne 10b ret +/* + * Mismatch was found. + * + * Before we compute it we narrow down the range (16 -> 8 -> 4 bytes). + */ +ALIGN_TEXT 10320016: leaq 16(%rdi),%rdi leaq 16(%rsi),%rsi 10320000: -/* - * Mismatch was found within a 16 bytes range. The part of the routine - * which calculates it only operates on sizes up to 8 bytes. Find the - * right part. - */ movq (%rdi),%r8 movq (%rsi),%r9 cmpq %r8,%r9 - jne 1f + jne 80f leaq 8(%rdi),%rdi leaq 8(%rsi),%rsi - jmp 1f + jmp 80f +ALIGN_TEXT +10081608: 10163224: leaq -8(%rdi,%rdx),%rdi leaq -8(%rsi,%rdx),%rsi - jmp 1f + jmp 80f +ALIGN_TEXT 10163216: leaq -16(%rdi,%rdx),%rdi leaq -16(%rsi,%rdx),%rsi - jmp 1f + jmp 80f +ALIGN_TEXT 10163208: -10081608: leaq 8(%rdi),%rdi leaq 8(%rsi),%rsi + jmp 80f +ALIGN_TEXT +10040804: + leaq -4(%rdi,%rdx),%rdi + leaq -4(%rsi,%rdx),%rsi jmp 1f +ALIGN_TEXT +80: + movl (%rdi),%r8d + movl (%rsi),%r9d + cmpl %r8d,%r9d + jne 1f + leaq 4(%rdi),%rdi + leaq 4(%rsi),%rsi + /* - * Mismatch was found. We have no more than 8 bytes to inspect. + * We have up to 4 bytes to inspect. */ -ALIGN_TEXT 1: movzbl (%rdi),%eax movzbl (%rsi),%r8d @@ -182,31 +198,6 @@ ALIGN_TEXT movzbl 3(%rdi),%eax movzbl 3(%rsi),%r8d - cmpb %r8b,%al - jne 2f - - movzbl 4(%rdi),%eax - movzbl 4(%rsi),%r8d - cmpb %r8b,%al - jne 2f - - movzbl 5(%rdi),%eax - movzbl 5(%rsi),%r8d - cmpb %r8b,%al - jne 2f - - movzbl 6(%rdi),%eax - movzbl 6(%rsi),%r8d - cmpb %r8b,%al - jne 2f - - movzbl 7(%rdi),%eax - movzbl 7(%rsi),%r8d - cmpb %r8b,%al - jne 2f - - xorl %eax,%eax - ret 2: subl %r8d,%eax ret
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