/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│ │vi: set et ft=asm ts=8 sw=8 fenc=utf-8 :vi│ ╞══════════════════════════════════════════════════════════════════════════════╡ │ Copyright 2020 Justine Alexandra Roberts Tunney │ │ │ │ Permission to use, copy, modify, and/or distribute this software for │ │ any purpose with or without fee is hereby granted, provided that the │ │ above copyright notice and this permission notice appear in all copies. │ │ │ │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │ │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │ │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │ │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │ │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │ │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │ │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │ │ PERFORMANCE OF THIS SOFTWARE. │ ╚─────────────────────────────────────────────────────────────────────────────*/ #include "libc/nexgen32e/x86feature.h" #include "libc/macros.internal.h" // Returns pointer to first instance of character. // // @param rdi is a non-null NUL-terminated wchar_t string pointer // @param esi is the search word // @return rax points to character, or to NUL word if not found // @note this won't return NULL if search character is NUL wcschrnul: .leafprologue .profilable or $-1,%r9 jmp 0f // Returns pointer to first instance of character. // // @param rdi is a non-null NUL-terminated wchar_t string pointer // @param esi is the search word // @return rax points to first result, or NULL if not found // @note this won't return NULL if search character is NUL // @asyncsignalsafe wcschr: .leafprologue .profilable xor %r9,%r9 0: mov %esi,%edx xor %r11d,%r11d pushpop -1,%rsi xor %r8,%r8 jmp wcssak // Returns length of wchar_t string w/ security blankets. // // This is like wcsnlen() except it'll return 0 if (1) RDI is NULL // or (2) a NUL-terminator wasn't found in the first RSI chars. // // @param rdi is a nullable NUL-terminated wchar_t string pointer // @param rsi is the maximum number of chars to consider // @return rax is the number of chars, excluding the NUL wcsnlen_s: .leafprologue .profilable xor %eax,%eax xor %r10d,%r10d test %rdi,%rdi jnz 0f .leafepilogue .endfn wcsnlen_s,globl // Returns length of NUL-terminated wchar_t string. // // @param rdi is non-null NUL-terminated wchar_t string pointer // @return rax is the number of chars, excluding the NUL // @asyncsignalsafe wcslen: or $-1,%rsi // fallthrough // Returns length of NUL-terminated memory, with limit. // // @param rdi is non-null memory // @param rsi is the maximum number of chars to consider // @return rax is the number of chars, excluding the NUL // @asyncsignalsafe wcsnlen:.leafprologue .profilable or $-1,%r10 0: xor %edx,%edx xor %r11d,%r11d mov %rdi,%r8 jmp wcssak // Returns pointer to first instance of character in range. // // @param rdi is a non-null pointer to memory // @param esi is the search word // @return rax points to word if found, or else undefined behavior rawwmemchr: or $-1,%rdx // fallthrough // Returns pointer to first instance of character in range. // // @param rdi is a non-null pointer to memory // @param esi is the int32_t search word (officially wchar_t) // @param rdx is length of memory in chars // @return rax points to word if found or NULL // @asyncsignalsafe wmemchr:.leafprologue .profilable xor %r8,%r8 xor %r10,%r10 mov %rdx,%rcx mov %esi,%edx mov %esi,%r11d mov %rcx,%rsi // fallthrough // Swiss army knife of wchar_t string scanning. // Seven fast functions in one. // // @param rdi is non-null wchar_t string memory // @param rsi is max number of chars to consider // @param edx is search character #1 // @param r11d is search character #2 // @param r8 is subtracted from result (for length vs. pointer) // @param r9 masks result if r11w is found (for NUL vs. NULL) // @param r10 masks result on chars exhausted (for length v. NULL) // @return rax end pointer after r8/r9/r10 modifications wcssak: lea -4(%rdi),%rax .align 16 1: add $4,%rax sub $1,%rsi jb .Lend test $31,%al jz .Lfast .Lint: mov (%rax),%ecx cmp %ecx,%edx je .Ldone cmp %ecx,%r11d je .Lnul jmp 1b .Ldone: sub %r8,%rax jmp .Lret .Lend: mov %r10,%r9 .Lnul: sub %r8,%rax and %r9,%rax .Lret: test %r8,%r8 jz 0f shr $2,%rax 0: .leafepilogue .Lslow: add $8,%rsi jmp .Lint .Lfast: #if !X86_NEED(AVX2) testb X86_HAVE(AVX2)+kCpuids(%rip) jz .Lint #endif movd %edx,%xmm0 movd %r11d,%xmm1 vpbroadcastd %xmm0,%ymm0 vpbroadcastd %xmm1,%ymm1 sub $32,%rax 1: add $32,%rax sub $8,%rsi jb .Lslow vmovdqa (%rax),%ymm2 vpcmpeqd %ymm0,%ymm2,%ymm3 vpcmpeqd %ymm1,%ymm2,%ymm2 vpor %ymm3,%ymm2,%ymm2 vpmovmskb %ymm2,%ecx bsf %ecx,%ecx je 1b vzeroupper add %rcx,%rax jmp .Lint .endfn wcssak .endfn wmemchr,globl .endfn rawwmemchr,globl .endfn wcsnlen,globl .endfn wcslen,globl .endfn wcschr,globl .endfn wcschrnul,globl .source __FILE__