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><H1
CLASS="title"
>L. GMP Functions</H1
><DIV
CLASS="PARTINTRO"
><A
NAME="AEN64093"
></A
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.intro"
>简介</A
></H1
><P
> These functions allow you to work with arbitrary-length integers
using the GNU <ACRONYM
CLASS="acronym"
>MP</ACRONYM
> library.
</P
><P
> These functions have been added in PHP 4.0.4.
</P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>
Most GMP functions accept GMP number arguments, defined as
<TT
CLASS="literal"
>resource</TT
> below. However, most of these
functions will also accept numeric and string arguments, given
that it is possible to convert the latter to a number. Also,
if there is a faster function that can operate on integer arguments,
it would be used instead of the slower function when the supplied arguments are
integers. This is done transparently, so the bottom line is that
you can use integers in every function that expects GMP
number. See also the <A
HREF="function.gmp-init.html"
><B
CLASS="function"
>gmp_init()</B
></A
> function.
</P
></BLOCKQUOTE
></DIV
><DIV
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><P
></P
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><TR
><TD
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><B
>警告</B
></TD
></TR
><TR
><TD
ALIGN="LEFT"
><P
> If you want to explicitly specify a large integer,
specify it as a string. If you don't do that, PHP will
interpret the integer-literal first, possibly resulting
in loss of precision, even before <TT
CLASS="literal"
>GMP</TT
>
comes into play.
</P
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>注意: </B
>
This extension is available on Windows platforms since PHP 5.1.0.
</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.requirements"
>需求</A
></H1
><P
> You can download the <ACRONYM
CLASS="acronym"
>GMP</ACRONYM
> library from <A
HREF="http://www.swox.com/gmp/"
TARGET="_top"
>http://www.swox.com/gmp/</A
>. This site also has the
<ACRONYM
CLASS="acronym"
>GMP</ACRONYM
> manual available.
</P
><P
> You will need GMP version 2 or better to use these functions. Some
functions may require more recent version of the GMP library.
</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.installation"
>安装</A
></H1
><P
> In order to have these functions available, you must compile PHP with
<ACRONYM
CLASS="acronym"
>GMP</ACRONYM
> support by using the <CODE
CLASS="option"
>--with-gmp</CODE
> option.
</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.configuration"
>运行时配置</A
></H1
><P
>本扩展模块在 <TT
CLASS="filename"
>php.ini</TT
> 中未定义任何配置选项。</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.resources"
>资源类型</A
></H1
><P
> Most GPM functions operate on or return GMP number resources.
</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.constants"
>预定义常量</A
></H1
><P
>以下常量由本扩展模块定义，因此只有在本扩展模块被编译到
PHP 中，或者在运行时被动态加载后才有效。</P
><P
></P
><DIV
CLASS="variablelist"
><DL
><DT
><TT
CLASS="constant"
><B
>GMP_ROUND_ZERO</B
></TT
>
(<A
HREF="language.types.integer.html"
><B
CLASS="type"
>integer</B
></A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>GMP_ROUND_PLUSINF</B
></TT
>
(<A
HREF="language.types.integer.html"
><B
CLASS="type"
>integer</B
></A
>)</DT
><DD
><P
>
</P
></DD
><DT
><TT
CLASS="constant"
><B
>GMP_ROUND_MINUSINF</B
></TT
>
(<A
HREF="language.types.integer.html"
><B
CLASS="type"
>integer</B
></A
>)</DT
><DD
><P
>
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.examples"
>范例</A
></H1
><P
> <TABLE
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><TR
><TD
><DIV
CLASS="example"
><A
NAME="AEN64152"
></A
><P
><B
>例 1. Factorial function using GMP</B
></P
><TABLE
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><TD
><code><font color="#000000">
<font color="#0000BB"><?php<br /></font><font color="#007700">function </font><font color="#0000BB">fact</font><font color="#007700">(</font><font color="#0000BB">$x</font><font color="#007700">) <br />{<br /> </font><font color="#0000BB">$return </font><font color="#007700">= </font><font color="#0000BB">1</font><font color="#007700">;<br /> for (</font><font color="#0000BB">$i</font><font color="#007700">=</font><font color="#0000BB">2</font><font color="#007700">; </font><font color="#0000BB">$i </font><font color="#007700">< </font><font color="#0000BB">$x</font><font color="#007700">; </font><font color="#0000BB">$i</font><font color="#007700">++) {<br /> </font><font color="#0000BB">$return </font><font color="#007700">= </font><font color="#0000BB">gmp_mul</font><font color="#007700">(</font><font color="#0000BB">$return</font><font color="#007700">, </font><font color="#0000BB">$i</font><font color="#007700">);<br /> }<br /> return </font><font color="#0000BB">$return</font><font color="#007700">;<br />}<br /><br />echo </font><font color="#0000BB">gmp_strval</font><font color="#007700">(</font><font color="#0000BB">fact</font><font color="#007700">(</font><font color="#0000BB">1000</font><font color="#007700">)) . </font><font color="#DD0000">"\n"</font><font color="#007700">;<br /></font><font color="#0000BB">?></font>
</font>
</code></TD
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></TD
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>
</P
><P
> This will calculate factorial of 1000 (pretty big number)
very fast.
</P
></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="gmp.seealso"
>参见</A
></H1
><P
> More mathematical functions can be found in the sections
<A
HREF="ref.bc.html"
>BCMath Arbitrary Precision Mathematics Functions</A
>
and <A
HREF="ref.math.html"
>Mathematical Functions</A
>.
</P
></DIV
></DIV
><DIV
CLASS="TOC"
><DL
><DT
><B
>目录</B
></DT
><DT
><A
HREF="function.gmp-abs.html"
>gmp_abs</A
> -- Absolute value</DT
><DT
><A
HREF="function.gmp-add.html"
>gmp_add</A
> -- Add numbers</DT
><DT
><A
HREF="function.gmp-and.html"
>gmp_and</A
> -- Logical AND</DT
><DT
><A
HREF="function.gmp-clrbit.html"
>gmp_clrbit</A
> -- Clear bit</DT
><DT
><A
HREF="function.gmp-cmp.html"
>gmp_cmp</A
> -- Compare numbers</DT
><DT
><A
HREF="function.gmp-com.html"
>gmp_com</A
> -- Calculates one's complement</DT
><DT
><A
HREF="function.gmp-div-q.html"
>gmp_div_q</A
> -- Divide numbers</DT
><DT
><A
HREF="function.gmp-div-qr.html"
>gmp_div_qr</A
> -- Divide numbers and get quotient and remainder</DT
><DT
><A
HREF="function.gmp-div-r.html"
>gmp_div_r</A
> -- Remainder of the division of numbers</DT
><DT
><A
HREF="function.gmp-div.html"
>gmp_div</A
> -- 别名 <A
HREF="function.gmp-div-q.html"
><B
CLASS="function"
>gmp_div_q()</B
></A
></DT
><DT
><A
HREF="function.gmp-divexact.html"
>gmp_divexact</A
> -- Exact division of numbers</DT
><DT
><A
HREF="function.gmp-fact.html"
>gmp_fact</A
> -- Factorial</DT
><DT
><A
HREF="function.gmp-gcd.html"
>gmp_gcd</A
> -- Calculate GCD</DT
><DT
><A
HREF="function.gmp-gcdext.html"
>gmp_gcdext</A
> -- Calculate GCD and multipliers</DT
><DT
><A
HREF="function.gmp-hamdist.html"
>gmp_hamdist</A
> -- Hamming distance</DT
><DT
><A
HREF="function.gmp-init.html"
>gmp_init</A
> -- Create GMP number</DT
><DT
><A
HREF="function.gmp-intval.html"
>gmp_intval</A
> -- Convert GMP number to integer</DT
><DT
><A
HREF="function.gmp-invert.html"
>gmp_invert</A
> -- Inverse by modulo</DT
><DT
><A
HREF="function.gmp-jacobi.html"
>gmp_jacobi</A
> -- Jacobi symbol</DT
><DT
><A
HREF="function.gmp-legendre.html"
>gmp_legendre</A
> -- Legendre symbol</DT
><DT
><A
HREF="function.gmp-mod.html"
>gmp_mod</A
> -- Modulo operation</DT
><DT
><A
HREF="function.gmp-mul.html"
>gmp_mul</A
> -- Multiply numbers</DT
><DT
><A
HREF="function.gmp-neg.html"
>gmp_neg</A
> -- Negate number</DT
><DT
><A
HREF="function.gmp-nextprime.html"
>gmp_nextprime</A
> -- Find next prime number</DT
><DT
><A
HREF="function.gmp-or.html"
>gmp_or</A
> -- Logical OR</DT
><DT
><A
HREF="function.gmp-perfect-square.html"
>gmp_perfect_square</A
> -- Perfect square check</DT
><DT
><A
HREF="function.gmp-popcount.html"
>gmp_popcount</A
> -- Population count</DT
><DT
><A
HREF="function.gmp-pow.html"
>gmp_pow</A
> -- Raise number into power</DT
><DT
><A
HREF="function.gmp-powm.html"
>gmp_powm</A
> -- Raise number into power with modulo</DT
><DT
><A
HREF="function.gmp-prob-prime.html"
>gmp_prob_prime</A
> -- Check if number is "probably prime"</DT
><DT
><A
HREF="function.gmp-random.html"
>gmp_random</A
> -- Random number</DT
><DT
><A
HREF="function.gmp-scan0.html"
>gmp_scan0</A
> -- Scan for 0</DT
><DT
><A
HREF="function.gmp-scan1.html"
>gmp_scan1</A
> -- Scan for 1</DT
><DT
><A
HREF="function.gmp-setbit.html"
>gmp_setbit</A
> -- Set bit</DT
><DT
><A
HREF="function.gmp-sign.html"
>gmp_sign</A
> -- Sign of number</DT
><DT
><A
HREF="function.gmp-sqrt.html"
>gmp_sqrt</A
> -- Calculate square root</DT
><DT
><A
HREF="function.gmp-sqrtrem.html"
>gmp_sqrtrem</A
> --
Square root with remainder
</DT
><DT
><A
HREF="function.gmp-strval.html"
>gmp_strval</A
> -- Convert GMP number to string</DT
><DT
><A
HREF="function.gmp-sub.html"
>gmp_sub</A
> -- Subtract numbers</DT
><DT
><A
HREF="function.gmp-xor.html"
>gmp_xor</A
> -- Logical XOR</DT
></DL
></DIV
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