text: /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
  │vi: set net ft=c ts=2 sts=2 sw=2 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/dce.h"
  #include "libc/nexgen32e/crc32.h"
  #include "libc/nexgen32e/x86feature.h"
  #include "libc/str/str.h"
  #include "libc/testlib/testlib.h"
  
  #define FANATICS "Fanatics"
  
  static const char hyperion[] =
      FANATICS " have their dreams, wherewith they weave / "
               "A paradise for a sect; the savage too / "
               "From forth the loftiest fashion of his sleep / "
               "...";
  
  TEST(crc32c, test) {
    EXPECT_EQ(0, crc32c(0, "", 0));
    EXPECT_EQ(crc32c(0, "hello", 5), crc32c(0, "hello", 5));
    EXPECT_EQ(0xe3069283, crc32c(0, "123456789", 9));
    EXPECT_EQ(0x6d6eefba, crc32c(0, hyperion, strlen(hyperion)));
    EXPECT_EQ(0x6d6eefba, crc32c(crc32c(0, FANATICS, strlen(FANATICS)),
                                 hyperion + strlen(FANATICS),
                                 strlen(hyperion) - strlen(FANATICS)));
  }
  
  FIXTURE(crc32c, pure_) {
    *(void **)(&crc32c) = (void *)crc32c_pure;
  }
  
  FIXTURE(crc32c, sse42_) {
    if (X86_HAVE(SSE4_2)) {
      *(void **)(&crc32c) = (void *)crc32c_sse42;
    }
  }
  