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author | marha <marha@users.sourceforge.net> | 2012-12-10 08:55:36 +0100 |
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committer | marha <marha@users.sourceforge.net> | 2012-12-10 08:55:36 +0100 |
commit | a0124a5e8e70979d2c24ef55285da989fdad766a (patch) | |
tree | 5cea5c9804a8edf67bc7260e0851a20d21324547 /pixman/test/utils-prng.c | |
parent | 514b4afb64ccbf8e954270105ed5064272a2be68 (diff) | |
parent | 0328076efb5ff6e62152c09e38d0d11f7931d07b (diff) | |
download | vcxsrv-a0124a5e8e70979d2c24ef55285da989fdad766a.tar.gz vcxsrv-a0124a5e8e70979d2c24ef55285da989fdad766a.tar.bz2 vcxsrv-a0124a5e8e70979d2c24ef55285da989fdad766a.zip |
Merge remote-tracking branch 'origin/released'
* origin/released:
fontconfig libX11 mesa pixman git update 10 dec 2012
Conflicts:
fontconfig/src/fcxml.c
Diffstat (limited to 'pixman/test/utils-prng.c')
-rw-r--r-- | pixman/test/utils-prng.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/pixman/test/utils-prng.c b/pixman/test/utils-prng.c new file mode 100644 index 000000000..7c2dd6a9a --- /dev/null +++ b/pixman/test/utils-prng.c @@ -0,0 +1,238 @@ +/* + * Copyright © 2012 Siarhei Siamashka <siarhei.siamashka@gmail.com> + * + * Based on the public domain implementation of small noncryptographic PRNG + * authored by Bob Jenkins: http://burtleburtle.net/bob/rand/smallprng.html + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#include "utils.h" +#include "utils-prng.h" + +void smallprng_srand_r (smallprng_t *x, uint32_t seed) +{ + uint32_t i; + x->a = 0xf1ea5eed, x->b = x->c = x->d = seed; + for (i = 0; i < 20; ++i) + smallprng_rand_r (x); +} + +/* + * Set a 32-bit seed for PRNG + * + * LCG is used here for generating independent seeds for different + * smallprng instances (in the case if smallprng is also used for + * generating these seeds, "Big Crush" test from TestU01 detects + * some problems in the glued 'prng_rand_128_r' output data). + * Actually we might be even better using some cryptographic + * hash for this purpose, but LCG seems to be also enough for + * passing "Big Crush". + */ +void prng_srand_r (prng_t *x, uint32_t seed) +{ +#ifdef GCC_VECTOR_EXTENSIONS_SUPPORTED + int i; + prng_rand_128_data_t dummy; + smallprng_srand_r (&x->p0, seed); + x->a[0] = x->a[1] = x->a[2] = x->a[3] = 0xf1ea5eed; + x->b[0] = x->c[0] = x->d[0] = (seed = seed * 1103515245 + 12345); + x->b[1] = x->c[1] = x->d[1] = (seed = seed * 1103515245 + 12345); + x->b[2] = x->c[2] = x->d[2] = (seed = seed * 1103515245 + 12345); + x->b[3] = x->c[3] = x->d[3] = (seed = seed * 1103515245 + 12345); + for (i = 0; i < 20; ++i) + prng_rand_128_r (x, &dummy); +#else + smallprng_srand_r (&x->p0, seed); + smallprng_srand_r (&x->p1, (seed = seed * 1103515245 + 12345)); + smallprng_srand_r (&x->p2, (seed = seed * 1103515245 + 12345)); + smallprng_srand_r (&x->p3, (seed = seed * 1103515245 + 12345)); + smallprng_srand_r (&x->p4, (seed = seed * 1103515245 + 12345)); +#endif +} + +static force_inline void +store_rand_128_data (void *addr, prng_rand_128_data_t *d, int aligned) +{ +#ifdef GCC_VECTOR_EXTENSIONS_SUPPORTED + if (aligned) + { + *(uint8x16 *)addr = d->vb; + return; + } +#endif + /* we could try something better for unaligned writes (packed attribute), + * but GCC is not very reliable: http://gcc.gnu.org/PR55454 */ + memcpy (addr, d, 16); +} + +/* + * Helper function and the actual code for "prng_randmemset_r" function + */ +static force_inline void +randmemset_internal (prng_t *prng, + uint8_t *buf, + size_t size, + prng_randmemset_flags_t flags, + int aligned) +{ + prng_t local_prng = *prng; + prng_rand_128_data_t randdata; + + while (size >= 16) + { + prng_rand_128_data_t t; + if (flags == 0) + { + prng_rand_128_r (&local_prng, &randdata); + } + else + { + prng_rand_128_r (&local_prng, &t); + prng_rand_128_r (&local_prng, &randdata); +#ifdef GCC_VECTOR_EXTENSIONS_SUPPORTED + if (flags & RANDMEMSET_MORE_FF) + { + const uint8x16 const_C0 = + { + 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, + 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0 + }; + randdata.vb |= (t.vb >= const_C0); + } + if (flags & RANDMEMSET_MORE_00) + { + const uint8x16 const_40 = + { + 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, + 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40 + }; + randdata.vb &= (t.vb >= const_40); + } +#else + #define PROCESS_ONE_LANE(i) \ + if (flags & RANDMEMSET_MORE_FF) \ + { \ + uint32_t mask_ff = (t.w[i] & (t.w[i] << 1)) & 0x80808080; \ + mask_ff |= mask_ff >> 1; \ + mask_ff |= mask_ff >> 2; \ + mask_ff |= mask_ff >> 4; \ + randdata.w[i] |= mask_ff; \ + } \ + if (flags & RANDMEMSET_MORE_00) \ + { \ + uint32_t mask_00 = (t.w[i] | (t.w[i] << 1)) & 0x80808080; \ + mask_00 |= mask_00 >> 1; \ + mask_00 |= mask_00 >> 2; \ + mask_00 |= mask_00 >> 4; \ + randdata.w[i] &= mask_00; \ + } + + PROCESS_ONE_LANE (0) + PROCESS_ONE_LANE (1) + PROCESS_ONE_LANE (2) + PROCESS_ONE_LANE (3) +#endif + } + if (is_little_endian ()) + { + store_rand_128_data (buf, &randdata, aligned); + buf += 16; + } + else + { +#ifdef GCC_VECTOR_EXTENSIONS_SUPPORTED + const uint8x16 bswap_shufflemask = + { + 3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12 + }; + randdata.vb = __builtin_shuffle (randdata.vb, bswap_shufflemask); + store_rand_128_data (buf, &randdata, aligned); + buf += 16; +#else + uint8_t t1, t2, t3, t4; + #define STORE_ONE_LANE(i) \ + t1 = randdata.b[i * 4 + 3]; \ + t2 = randdata.b[i * 4 + 2]; \ + t3 = randdata.b[i * 4 + 1]; \ + t4 = randdata.b[i * 4 + 0]; \ + *buf++ = t1; \ + *buf++ = t2; \ + *buf++ = t3; \ + *buf++ = t4; + + STORE_ONE_LANE (0) + STORE_ONE_LANE (1) + STORE_ONE_LANE (2) + STORE_ONE_LANE (3) +#endif + } + size -= 16; + } + while (size > 0) + { + uint8_t randbyte = prng_rand_r (&local_prng) & 0xFF; + if (flags != 0) + { + uint8_t t = prng_rand_r (&local_prng) & 0xFF; + if ((flags & RANDMEMSET_MORE_FF) && (t >= 0xC0)) + randbyte = 0xFF; + if ((flags & RANDMEMSET_MORE_00) && (t < 0x40)) + randbyte = 0x00; + } + *buf++ = randbyte; + size--; + } + *prng = local_prng; +} + +/* + * Fill memory buffer with random data. Flags argument may be used + * to tweak some statistics properties: + * RANDMEMSET_MORE_00 - set ~25% of bytes to 0x00 + * RANDMEMSET_MORE_FF - set ~25% of bytes to 0xFF + */ +void prng_randmemset_r (prng_t *prng, + void *voidbuf, + size_t size, + prng_randmemset_flags_t flags) +{ + uint8_t *buf = (uint8_t *)voidbuf; + if ((uintptr_t)buf & 15) + { + /* unaligned buffer */ + if (flags == 0) + randmemset_internal (prng, buf, size, 0, 0); + else if (flags == RANDMEMSET_MORE_00_AND_FF) + randmemset_internal (prng, buf, size, RANDMEMSET_MORE_00_AND_FF, 0); + else + randmemset_internal (prng, buf, size, flags, 0); + } + else + { + /* aligned buffer */ + if (flags == 0) + randmemset_internal (prng, buf, size, 0, 1); + else if (flags == RANDMEMSET_MORE_00_AND_FF) + randmemset_internal (prng, buf, size, RANDMEMSET_MORE_00_AND_FF, 1); + else + randmemset_internal (prng, buf, size, flags, 1); + } +} |