Re: [PATCH] tests/test-crc.c: New tests for future optimised implementation.

[Sam Russell]

Thanks, my mistake on the dropped CC

On Tue, 22 Oct 2024 at 22:24, Simon Josefsson <simon@josefsson.org> wrote:

Thanks, pushed in your name -- next time please attach git-format-patch
output that includes the commit message, and keep cc to the list.

/Simon

Sam Russell <sam.h.russell@gmail.com> writes:

>>  Why '__'?  I think they should be dropped.
>
> thanks, bad habit, other codebases use them as they work better with
> standard msvc... underscores removed
>
>> A detail, but if the variables aren't used use 'main (void)', which
>> sometimes silences some warning about unused variables.
>
> done
>
> On Tue, 22 Oct 2024 at 22:02, Simon Josefsson <simon@josefsson.org> wrote:
>
>> Sam Russell <sam.h.russell@gmail.com> writes:
>>
>> > +__uint32_t trailing_unaligned_byte_hashes[32] = {
>> > +__uint32_t leading_unaligned_byte_hashes[32] = {
>> > +__uint32_t variable_alignment_variable_length_hashes[] = {
>>
>> Why '__'?  I think they should be dropped.
>>
>> >  main (int argc, char *argv[])
>>
>> A detail, but if the variables aren't used use 'main (void)', which
>> sometimes silences some warning about unused variables.
>>
>> Otherwise looks ready to go!
>>
>> /Simon
>>
> diff --git a/ChangeLog b/ChangeLog
> index 26a4f7f239..3be4d786ea 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,9 @@
> +2024-10-17  Sam Russell  <sam.h.russell@gmail.com>
> +
> +     crc: New tests for non-byte-aligned data.
> +     * tests/test-crc.c: New tests.
> +     * modules/crc-tests (Files): Add dependency on randomb.c
> +
>  2024-10-16  Bruno Haible  <bruno@clisp.org>
> 
>       crc tests: Add a benchmark program.
> diff --git a/modules/crc-tests b/modules/crc-tests
> index 97875264d9..ee05fb15ac 100644
> --- a/modules/crc-tests
> +++ b/modules/crc-tests
> @@ -15,5 +15,6 @@ Makefile.am:
>  TESTS += test-crc
>  check_PROGRAMS += test-crc
>  noinst_PROGRAMS += bench-crc
> +test_crc_SOURCES = test-crc.c randomb.c
>  bench_crc_SOURCES = bench-crc.c randomb.c
>  bench_crc_CPPFLAGS = $(AM_CPPFLAGS) -DNDEBUG
> diff --git a/tests/test-crc.c b/tests/test-crc.c
> index 16d2ff08eb..8826747da7 100644
> --- a/tests/test-crc.c
> +++ b/tests/test-crc.c
> @@ -21,11 +21,47 @@
>  #include "crc.h"
> 
>  #include <stdio.h>
> +#include <string.h>
> +
> +#include "macros.h"
> +
> +#define MAX_ALIGNMENT 32
> +
> +uint32_t trailing_unaligned_byte_hashes[32] = {
> +  0xDFDD19BE, 0xD2D258E4, 0x3F67D485, 0xFF300DA4, 0xFC46B871,
> +  0x6B97174C, 0x3C6873C6, 0x3DE4FDA4, 0x783A2D5F, 0x2ECC37AC,
> +  0xFEFAD741, 0x5FFB72DF, 0xF6E6DD29, 0xCD21E04E, 0x78CAE842,
> +  0xCFC25F71, 0x7DC85CEE, 0xC971E8DA, 0x541726C1, 0xB15FFE02,
> +  0xFABE629D, 0x4F254C30, 0x444B083F, 0x049F6D1D, 0x2D0670E0,
> +  0x719C83F9, 0xEB7FAABC, 0xF0E4ECEE, 0x80958327, 0xD3566178,
> +  0xD1683190, 0x7ABB3299
> +};
> +
> +uint32_t leading_unaligned_byte_hashes[32] = {
> +  0xA6C6EC55, 0x10BA5C53, 0xE991A1AB, 0xD9279D86, 0xEF21C396,
> +  0x78A4387C, 0x2F865A77, 0xAEA7587C, 0x9779C9D0, 0x914DD47A,
> +  0xB42B53CB, 0x47D39201, 0xE53E891F, 0xB4501BA1, 0xE946965F,
> +  0xF092BC6F, 0xA4D33D75, 0xD602ECA6, 0x107142FB, 0xD83B4AFD,
> +  0x9B9CE2B9, 0xCF2C3E17, 0xCDE401A1, 0xE686DFE7, 0x5137E14F,
> +  0xB309A32D, 0x2E1BB47F, 0xECA84001, 0x1F5B5472, 0x5BA21753,
> +  0x203ACDCA, 0x48B56C22
> +};
> +
> +uint32_t variable_alignment_variable_length_hashes[] = {
> +  0x00000000, 0xB40BBE37, 0x98662B02, 0x062ED334, 0xFD64D7A9, 0xCA47A65D,
> +  0x70A0B329, 0x191C96C2, 0xFECD07E0, 0x5120CD3D, 0xC886714D, 0x5416D158,
> +  0xA9E8B882, 0x7B18C316, 0x0A7BB6E4, 0x19664DC7, 0x71A8E3C4, 0xDD7CD42A,
> +  0x95623656, 0x2C4CFCBD, 0x7046B873, 0x7777762E, 0xAD10FF30, 0x15773DB6,
> +  0x0515202E, 0xE0D0FC3E, 0x2F8FAC7B, 0x3A9ADE62, 0x13560288, 0x8BADEEE8,
> +  0x4B8F79A9, 0xBDF67D65
> +};
> 
>  int
> -main (int argc, char *argv[])
> +main (void)
>  {
>    uint32_t p;
> +  size_t i, j;
> +  char data[MAX_ALIGNMENT * 3];
> 
>    p = crc32_update_no_xor (42, "foo", 3);
>    if (p != 0x46e87f05)
> @@ -55,5 +91,52 @@ main (int argc, char *argv[])
>        return 1;
>      }
> 
> +  /*
> +   * Tests for new CRC32 implementation
> +   * The original implementation works on a byte-by-byte basis
> +   * but new implementations may work on longer alignments.
> +   * This test will confirm correct operation with non-aligned
> +   * data.
> +   */
> +
> +  /* Test for trailing unaligned bytes */
> +
> +  for (i = 0; i < MAX_ALIGNMENT; i++)
> +    {
> +      p = crc32_update_no_xor (0, randomb, MAX_ALIGNMENT + i);
> +      if (p != trailing_unaligned_byte_hashes[i])
> +        {
> +          printf ("aligned c at %lu length %lu got %lx\n", (size_t) 0, MAX_ALIGNMENT + i, (unsigned long) p);
> +          return 1;
> +        }
> +    }
> +
> +  /* Test for leading unaligned bytes */
> +
> +  for (i = 0; i < MAX_ALIGNMENT; i++)
> +    {
> +      p = crc32_update_no_xor (0, randomb + i, (MAX_ALIGNMENT * 2) - i);
> +      if (p != leading_unaligned_byte_hashes[i])
> +        {
> +          printf ("aligned c at %lu length %lu got %lx\n", i, (MAX_ALIGNMENT * 2) - i, (unsigned long) p);
> +          return 1;
> +        }
> +    }
> +
> +  /* Combined test of multiple lengths at multiple alignments */
> +
> +  for (i = 0; i < MAX_ALIGNMENT; i++)
> +    for (j = 0; j < MAX_ALIGNMENT; j++)
> +      {
> +        memcpy(data + i, randomb, MAX_ALIGNMENT * 2);
> +        p = crc32_update_no_xor (0, data + i, j);
> +        if (p != variable_alignment_variable_length_hashes[j])
> +          {
> +            printf ("aligned c at %lu length %lu got %lx\n", i, j, (unsigned long) p);
> +            return 1;
> +          }
> +      }
> +
> +
>    return 0;
>  }
>