updates from p9p
This commit is contained in:
54
libc/pow10.c
54
libc/pow10.c
@ -1,5 +1,21 @@
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#include <u.h>
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#include <libc.h>
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/*
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* The authors of this software are Rob Pike and Ken Thompson.
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* Copyright (c) 2002 by Lucent Technologies.
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* Permission to use, copy, modify, and distribute this software for any
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* purpose without fee is hereby granted, provided that this entire notice
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* is included in all copies of any software which is or includes a copy
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* or modification of this software and in all copies of the supporting
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* documentation for such software.
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* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
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* ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
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* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
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*/
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#include <stdarg.h>
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#include <string.h>
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#include "plan9.h"
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#include "fmt.h"
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#include "fmtdef.h"
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/*
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* this table might overflow 127-bit exponent representations.
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@ -9,41 +25,33 @@
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* the presumption is that C converts fp numbers better
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* than multipication of lower powers of 10.
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*/
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static
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double tab[] =
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{
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1.0e0, 1.0e1, 1.0e2, 1.0e3, 1.0e4, 1.0e5, 1.0e6, 1.0e7, 1.0e8, 1.0e9,
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1.0e10, 1.0e11, 1.0e12, 1.0e13, 1.0e14, 1.0e15, 1.0e16, 1.0e17, 1.0e18, 1.0e19,
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1.0e20, 1.0e21, 1.0e22, 1.0e23, 1.0e24, 1.0e25, 1.0e26, 1.0e27, 1.0e28, 1.0e29,
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1.0e30, 1.0e31, 1.0e32, 1.0e33, 1.0e34, 1.0e35, 1.0e36, 1.0e37, 1.0e38, 1.0e39,
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1.0e40, 1.0e41, 1.0e42, 1.0e43, 1.0e44, 1.0e45, 1.0e46, 1.0e47, 1.0e48, 1.0e49,
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1.0e50, 1.0e51, 1.0e52, 1.0e53, 1.0e54, 1.0e55, 1.0e56, 1.0e57, 1.0e58, 1.0e59,
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1.0e60, 1.0e61, 1.0e62, 1.0e63, 1.0e64, 1.0e65, 1.0e66, 1.0e67, 1.0e68, 1.0e69,
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1.0e70, 1.0e71, 1.0e72, 1.0e73, 1.0e74, 1.0e75, 1.0e76, 1.0e77, 1.0e78, 1.0e79,
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1.0e80, 1.0e81, 1.0e82, 1.0e83, 1.0e84, 1.0e85, 1.0e86, 1.0e87, 1.0e88, 1.0e89,
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1.0e90, 1.0e91, 1.0e92, 1.0e93, 1.0e94, 1.0e95, 1.0e96, 1.0e97, 1.0e98, 1.0e99,
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1.0e100,1.0e101,1.0e102,1.0e103,1.0e104,1.0e105,1.0e106,1.0e107,1.0e108,1.0e109,
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1.0e110,1.0e111,1.0e112,1.0e113,1.0e114,1.0e115,1.0e116,1.0e117,1.0e118,1.0e119,
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1.0e120,1.0e121,1.0e122,1.0e123,1.0e124,1.0e125,1.0e126,1.0e127,1.0e128,1.0e129,
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1.0e130,1.0e131,1.0e132,1.0e133,1.0e134,1.0e135,1.0e136,1.0e137,1.0e138,1.0e139,
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1.0e140,1.0e141,1.0e142,1.0e143,1.0e144,1.0e145,1.0e146,1.0e147,1.0e148,1.0e149,
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1.0e150,1.0e151,1.0e152,1.0e153,1.0e154,1.0e155,1.0e156,1.0e157,1.0e158,1.0e159,
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1.0e0, 1.0e1, 1.0e2, 1.0e3, 1.0e4, 1.0e5, 1.0e6, 1.0e7, 1.0e8, 1.0e9,
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1.0e10,1.0e11,1.0e12,1.0e13,1.0e14,1.0e15,1.0e16,1.0e17,1.0e18,1.0e19,
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1.0e20,1.0e21,1.0e22,1.0e23,1.0e24,1.0e25,1.0e26,1.0e27,1.0e28,1.0e29,
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1.0e30,1.0e31,1.0e32,1.0e33,1.0e34,1.0e35,1.0e36,1.0e37,1.0e38,1.0e39,
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1.0e40,1.0e41,1.0e42,1.0e43,1.0e44,1.0e45,1.0e46,1.0e47,1.0e48,1.0e49,
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1.0e50,1.0e51,1.0e52,1.0e53,1.0e54,1.0e55,1.0e56,1.0e57,1.0e58,1.0e59,
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1.0e60,1.0e61,1.0e62,1.0e63,1.0e64,1.0e65,1.0e66,1.0e67,1.0e68,1.0e69,
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};
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double
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pow10(int n)
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__fmtpow10(int n)
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{
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int m;
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if(n < 0) {
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n = -n;
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if(n < sizeof(tab)/sizeof(tab[0]))
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if(n < (int)(sizeof(tab)/sizeof(tab[0])))
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return 1/tab[n];
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m = n/2;
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return 1/(pow10(m) * pow10(n-m));
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return __fmtpow10(-m) * __fmtpow10(m-n);
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}
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if(n < sizeof(tab)/sizeof(tab[0]))
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if(n < (int)(sizeof(tab)/sizeof(tab[0])))
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return tab[n];
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m = n/2;
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return pow10(m) * pow10(n-m);
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return __fmtpow10(m) * __fmtpow10(n-m);
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}
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