[Gmp-commit] /var/hg/gmp: mpn/generic/sqrtrem.c (invsqrttab): Reduce size rem...

mercurial at gmplib.org mercurial at gmplib.org
Wed May 9 07:59:32 CEST 2012


details:   /var/hg/gmp/rev/bf40df76fb25
changeset: 14956:bf40df76fb25
user:      Marco Bodrato <bodrato at mail.dm.unipi.it>
date:      Wed May 09 07:59:28 2012 +0200
description:
mpn/generic/sqrtrem.c (invsqrttab): Reduce size removing common byte.

diffstat:

 ChangeLog             |    2 +
 mpn/generic/sqrtrem.c |  100 +++++++++++++++++++++++++-------------------------
 2 files changed, 52 insertions(+), 50 deletions(-)

diffs (130 lines):

diff -r f518302fa030 -r bf40df76fb25 ChangeLog
--- a/ChangeLog	Wed May 09 05:50:26 2012 +0200
+++ b/ChangeLog	Wed May 09 07:59:28 2012 +0200
@@ -2,6 +2,8 @@
 
 	* mini-gmp/mini-gmp.c: merge mpz_rootrem and mpz_sqrtrem.
 
+	* mpn/generic/sqrtrem.c (invsqrttab): Reduce size removing common byte.
+
 2012-05-08  Torbjorn Granlund  <tege at gmplib.org>
 
 	* mpn/minithres/gmp-mparam.h (REDC_1_TO_REDC_N_THRESHOLD): Up to 9, for
diff -r f518302fa030 -r bf40df76fb25 mpn/generic/sqrtrem.c
--- a/mpn/generic/sqrtrem.c	Wed May 09 05:50:26 2012 +0200
+++ b/mpn/generic/sqrtrem.c	Wed May 09 07:59:28 2012 +0200
@@ -37,56 +37,56 @@
 #include "gmp-impl.h"
 #include "longlong.h"
 
-static const unsigned short invsqrttab[384] =
+static const unsigned char invsqrttab[384] = /* The common 0x100 was removed */
 {
-  0x1ff,0x1fd,0x1fb,0x1f9,0x1f7,0x1f5,0x1f3,0x1f2, /* sqrt(1/80)..sqrt(1/87) */
-  0x1f0,0x1ee,0x1ec,0x1ea,0x1e9,0x1e7,0x1e5,0x1e4, /* sqrt(1/88)..sqrt(1/8f) */
-  0x1e2,0x1e0,0x1df,0x1dd,0x1db,0x1da,0x1d8,0x1d7, /* sqrt(1/90)..sqrt(1/97) */
-  0x1d5,0x1d4,0x1d2,0x1d1,0x1cf,0x1ce,0x1cc,0x1cb, /* sqrt(1/98)..sqrt(1/9f) */
-  0x1c9,0x1c8,0x1c6,0x1c5,0x1c4,0x1c2,0x1c1,0x1c0, /* sqrt(1/a0)..sqrt(1/a7) */
-  0x1be,0x1bd,0x1bc,0x1ba,0x1b9,0x1b8,0x1b7,0x1b5, /* sqrt(1/a8)..sqrt(1/af) */
-  0x1b4,0x1b3,0x1b2,0x1b0,0x1af,0x1ae,0x1ad,0x1ac, /* sqrt(1/b0)..sqrt(1/b7) */
-  0x1aa,0x1a9,0x1a8,0x1a7,0x1a6,0x1a5,0x1a4,0x1a3, /* sqrt(1/b8)..sqrt(1/bf) */
-  0x1a2,0x1a0,0x19f,0x19e,0x19d,0x19c,0x19b,0x19a, /* sqrt(1/c0)..sqrt(1/c7) */
-  0x199,0x198,0x197,0x196,0x195,0x194,0x193,0x192, /* sqrt(1/c8)..sqrt(1/cf) */
-  0x191,0x190,0x18f,0x18e,0x18d,0x18c,0x18c,0x18b, /* sqrt(1/d0)..sqrt(1/d7) */
-  0x18a,0x189,0x188,0x187,0x186,0x185,0x184,0x183, /* sqrt(1/d8)..sqrt(1/df) */
-  0x183,0x182,0x181,0x180,0x17f,0x17e,0x17e,0x17d, /* sqrt(1/e0)..sqrt(1/e7) */
-  0x17c,0x17b,0x17a,0x179,0x179,0x178,0x177,0x176, /* sqrt(1/e8)..sqrt(1/ef) */
-  0x176,0x175,0x174,0x173,0x172,0x172,0x171,0x170, /* sqrt(1/f0)..sqrt(1/f7) */
-  0x16f,0x16f,0x16e,0x16d,0x16d,0x16c,0x16b,0x16a, /* sqrt(1/f8)..sqrt(1/ff) */
-  0x16a,0x169,0x168,0x168,0x167,0x166,0x166,0x165, /* sqrt(1/100)..sqrt(1/107) */
-  0x164,0x164,0x163,0x162,0x162,0x161,0x160,0x160, /* sqrt(1/108)..sqrt(1/10f) */
-  0x15f,0x15e,0x15e,0x15d,0x15c,0x15c,0x15b,0x15a, /* sqrt(1/110)..sqrt(1/117) */
-  0x15a,0x159,0x159,0x158,0x157,0x157,0x156,0x156, /* sqrt(1/118)..sqrt(1/11f) */
-  0x155,0x154,0x154,0x153,0x153,0x152,0x152,0x151, /* sqrt(1/120)..sqrt(1/127) */
-  0x150,0x150,0x14f,0x14f,0x14e,0x14e,0x14d,0x14d, /* sqrt(1/128)..sqrt(1/12f) */
-  0x14c,0x14b,0x14b,0x14a,0x14a,0x149,0x149,0x148, /* sqrt(1/130)..sqrt(1/137) */
-  0x148,0x147,0x147,0x146,0x146,0x145,0x145,0x144, /* sqrt(1/138)..sqrt(1/13f) */
-  0x144,0x143,0x143,0x142,0x142,0x141,0x141,0x140, /* sqrt(1/140)..sqrt(1/147) */
-  0x140,0x13f,0x13f,0x13e,0x13e,0x13d,0x13d,0x13c, /* sqrt(1/148)..sqrt(1/14f) */
-  0x13c,0x13b,0x13b,0x13a,0x13a,0x139,0x139,0x139, /* sqrt(1/150)..sqrt(1/157) */
-  0x138,0x138,0x137,0x137,0x136,0x136,0x135,0x135, /* sqrt(1/158)..sqrt(1/15f) */
-  0x135,0x134,0x134,0x133,0x133,0x132,0x132,0x132, /* sqrt(1/160)..sqrt(1/167) */
-  0x131,0x131,0x130,0x130,0x12f,0x12f,0x12f,0x12e, /* sqrt(1/168)..sqrt(1/16f) */
-  0x12e,0x12d,0x12d,0x12d,0x12c,0x12c,0x12b,0x12b, /* sqrt(1/170)..sqrt(1/177) */
-  0x12b,0x12a,0x12a,0x129,0x129,0x129,0x128,0x128, /* sqrt(1/178)..sqrt(1/17f) */
-  0x127,0x127,0x127,0x126,0x126,0x126,0x125,0x125, /* sqrt(1/180)..sqrt(1/187) */
-  0x124,0x124,0x124,0x123,0x123,0x123,0x122,0x122, /* sqrt(1/188)..sqrt(1/18f) */
-  0x121,0x121,0x121,0x120,0x120,0x120,0x11f,0x11f, /* sqrt(1/190)..sqrt(1/197) */
-  0x11f,0x11e,0x11e,0x11e,0x11d,0x11d,0x11d,0x11c, /* sqrt(1/198)..sqrt(1/19f) */
-  0x11c,0x11b,0x11b,0x11b,0x11a,0x11a,0x11a,0x119, /* sqrt(1/1a0)..sqrt(1/1a7) */
-  0x119,0x119,0x118,0x118,0x118,0x118,0x117,0x117, /* sqrt(1/1a8)..sqrt(1/1af) */
-  0x117,0x116,0x116,0x116,0x115,0x115,0x115,0x114, /* sqrt(1/1b0)..sqrt(1/1b7) */
-  0x114,0x114,0x113,0x113,0x113,0x112,0x112,0x112, /* sqrt(1/1b8)..sqrt(1/1bf) */
-  0x112,0x111,0x111,0x111,0x110,0x110,0x110,0x10f, /* sqrt(1/1c0)..sqrt(1/1c7) */
-  0x10f,0x10f,0x10f,0x10e,0x10e,0x10e,0x10d,0x10d, /* sqrt(1/1c8)..sqrt(1/1cf) */
-  0x10d,0x10c,0x10c,0x10c,0x10c,0x10b,0x10b,0x10b, /* sqrt(1/1d0)..sqrt(1/1d7) */
-  0x10a,0x10a,0x10a,0x10a,0x109,0x109,0x109,0x109, /* sqrt(1/1d8)..sqrt(1/1df) */
-  0x108,0x108,0x108,0x107,0x107,0x107,0x107,0x106, /* sqrt(1/1e0)..sqrt(1/1e7) */
-  0x106,0x106,0x106,0x105,0x105,0x105,0x104,0x104, /* sqrt(1/1e8)..sqrt(1/1ef) */
-  0x104,0x104,0x103,0x103,0x103,0x103,0x102,0x102, /* sqrt(1/1f0)..sqrt(1/1f7) */
-  0x102,0x102,0x101,0x101,0x101,0x101,0x100,0x100  /* sqrt(1/1f8)..sqrt(1/1ff) */
+  0xff,0xfd,0xfb,0xf9,0xf7,0xf5,0xf3,0xf2, /* sqrt(1/80)..sqrt(1/87) */
+  0xf0,0xee,0xec,0xea,0xe9,0xe7,0xe5,0xe4, /* sqrt(1/88)..sqrt(1/8f) */
+  0xe2,0xe0,0xdf,0xdd,0xdb,0xda,0xd8,0xd7, /* sqrt(1/90)..sqrt(1/97) */
+  0xd5,0xd4,0xd2,0xd1,0xcf,0xce,0xcc,0xcb, /* sqrt(1/98)..sqrt(1/9f) */
+  0xc9,0xc8,0xc6,0xc5,0xc4,0xc2,0xc1,0xc0, /* sqrt(1/a0)..sqrt(1/a7) */
+  0xbe,0xbd,0xbc,0xba,0xb9,0xb8,0xb7,0xb5, /* sqrt(1/a8)..sqrt(1/af) */
+  0xb4,0xb3,0xb2,0xb0,0xaf,0xae,0xad,0xac, /* sqrt(1/b0)..sqrt(1/b7) */
+  0xaa,0xa9,0xa8,0xa7,0xa6,0xa5,0xa4,0xa3, /* sqrt(1/b8)..sqrt(1/bf) */
+  0xa2,0xa0,0x9f,0x9e,0x9d,0x9c,0x9b,0x9a, /* sqrt(1/c0)..sqrt(1/c7) */
+  0x99,0x98,0x97,0x96,0x95,0x94,0x93,0x92, /* sqrt(1/c8)..sqrt(1/cf) */
+  0x91,0x90,0x8f,0x8e,0x8d,0x8c,0x8c,0x8b, /* sqrt(1/d0)..sqrt(1/d7) */
+  0x8a,0x89,0x88,0x87,0x86,0x85,0x84,0x83, /* sqrt(1/d8)..sqrt(1/df) */
+  0x83,0x82,0x81,0x80,0x7f,0x7e,0x7e,0x7d, /* sqrt(1/e0)..sqrt(1/e7) */
+  0x7c,0x7b,0x7a,0x79,0x79,0x78,0x77,0x76, /* sqrt(1/e8)..sqrt(1/ef) */
+  0x76,0x75,0x74,0x73,0x72,0x72,0x71,0x70, /* sqrt(1/f0)..sqrt(1/f7) */
+  0x6f,0x6f,0x6e,0x6d,0x6d,0x6c,0x6b,0x6a, /* sqrt(1/f8)..sqrt(1/ff) */
+  0x6a,0x69,0x68,0x68,0x67,0x66,0x66,0x65, /* sqrt(1/100)..sqrt(1/107) */
+  0x64,0x64,0x63,0x62,0x62,0x61,0x60,0x60, /* sqrt(1/108)..sqrt(1/10f) */
+  0x5f,0x5e,0x5e,0x5d,0x5c,0x5c,0x5b,0x5a, /* sqrt(1/110)..sqrt(1/117) */
+  0x5a,0x59,0x59,0x58,0x57,0x57,0x56,0x56, /* sqrt(1/118)..sqrt(1/11f) */
+  0x55,0x54,0x54,0x53,0x53,0x52,0x52,0x51, /* sqrt(1/120)..sqrt(1/127) */
+  0x50,0x50,0x4f,0x4f,0x4e,0x4e,0x4d,0x4d, /* sqrt(1/128)..sqrt(1/12f) */
+  0x4c,0x4b,0x4b,0x4a,0x4a,0x49,0x49,0x48, /* sqrt(1/130)..sqrt(1/137) */
+  0x48,0x47,0x47,0x46,0x46,0x45,0x45,0x44, /* sqrt(1/138)..sqrt(1/13f) */
+  0x44,0x43,0x43,0x42,0x42,0x41,0x41,0x40, /* sqrt(1/140)..sqrt(1/147) */
+  0x40,0x3f,0x3f,0x3e,0x3e,0x3d,0x3d,0x3c, /* sqrt(1/148)..sqrt(1/14f) */
+  0x3c,0x3b,0x3b,0x3a,0x3a,0x39,0x39,0x39, /* sqrt(1/150)..sqrt(1/157) */
+  0x38,0x38,0x37,0x37,0x36,0x36,0x35,0x35, /* sqrt(1/158)..sqrt(1/15f) */
+  0x35,0x34,0x34,0x33,0x33,0x32,0x32,0x32, /* sqrt(1/160)..sqrt(1/167) */
+  0x31,0x31,0x30,0x30,0x2f,0x2f,0x2f,0x2e, /* sqrt(1/168)..sqrt(1/16f) */
+  0x2e,0x2d,0x2d,0x2d,0x2c,0x2c,0x2b,0x2b, /* sqrt(1/170)..sqrt(1/177) */
+  0x2b,0x2a,0x2a,0x29,0x29,0x29,0x28,0x28, /* sqrt(1/178)..sqrt(1/17f) */
+  0x27,0x27,0x27,0x26,0x26,0x26,0x25,0x25, /* sqrt(1/180)..sqrt(1/187) */
+  0x24,0x24,0x24,0x23,0x23,0x23,0x22,0x22, /* sqrt(1/188)..sqrt(1/18f) */
+  0x21,0x21,0x21,0x20,0x20,0x20,0x1f,0x1f, /* sqrt(1/190)..sqrt(1/197) */
+  0x1f,0x1e,0x1e,0x1e,0x1d,0x1d,0x1d,0x1c, /* sqrt(1/198)..sqrt(1/19f) */
+  0x1c,0x1b,0x1b,0x1b,0x1a,0x1a,0x1a,0x19, /* sqrt(1/1a0)..sqrt(1/1a7) */
+  0x19,0x19,0x18,0x18,0x18,0x18,0x17,0x17, /* sqrt(1/1a8)..sqrt(1/1af) */
+  0x17,0x16,0x16,0x16,0x15,0x15,0x15,0x14, /* sqrt(1/1b0)..sqrt(1/1b7) */
+  0x14,0x14,0x13,0x13,0x13,0x12,0x12,0x12, /* sqrt(1/1b8)..sqrt(1/1bf) */
+  0x12,0x11,0x11,0x11,0x10,0x10,0x10,0x0f, /* sqrt(1/1c0)..sqrt(1/1c7) */
+  0x0f,0x0f,0x0f,0x0e,0x0e,0x0e,0x0d,0x0d, /* sqrt(1/1c8)..sqrt(1/1cf) */
+  0x0d,0x0c,0x0c,0x0c,0x0c,0x0b,0x0b,0x0b, /* sqrt(1/1d0)..sqrt(1/1d7) */
+  0x0a,0x0a,0x0a,0x0a,0x09,0x09,0x09,0x09, /* sqrt(1/1d8)..sqrt(1/1df) */
+  0x08,0x08,0x08,0x07,0x07,0x07,0x07,0x06, /* sqrt(1/1e0)..sqrt(1/1e7) */
+  0x06,0x06,0x06,0x05,0x05,0x05,0x04,0x04, /* sqrt(1/1e8)..sqrt(1/1ef) */
+  0x04,0x04,0x03,0x03,0x03,0x03,0x02,0x02, /* sqrt(1/1f0)..sqrt(1/1f7) */
+  0x02,0x02,0x01,0x01,0x01,0x01,0x00,0x00  /* sqrt(1/1f8)..sqrt(1/1ff) */
 };
 
 /* Compute s = floor(sqrt(a0)), and *rp = a0 - s^2.  */
@@ -115,7 +115,7 @@
      iteration convert from 1/sqrt(a) to sqrt(a).  */
 
   abits = a0 >> (GMP_LIMB_BITS - 1 - 8);	/* extract bits for table lookup */
-  x0 = invsqrttab[abits - 0x80];		/* initial 1/sqrt(a) */
+  x0 = 0x100 | invsqrttab[abits - 0x80];	/* initial 1/sqrt(a) */
 
   /* x0 is now an 8 bits approximation of 1/sqrt(a0) */
 


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