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  68. 

  69. <body lang="en">

  70. <a name="Integer-library-routines"></a>

  71. <div class="header">

  72. <p>

  73. Next: <a href="Soft-float-library-routines.html#Soft-float-library-routines" accesskey="n" rel="next">Soft float library routines</a>, Up: <a href="Libgcc.html#Libgcc" accesskey="u" rel="up">Libgcc</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>

  74. </div>

  75. <hr>

  76. <a name="Routines-for-integer-arithmetic"></a>

  77. <h3 class="section">4.1 Routines for integer arithmetic</h3>

  78. 

  79. <p>The integer arithmetic routines are used on platforms that don&rsquo;t provide

  80. hardware support for arithmetic operations on some modes.

  81. </p>

  82. <a name="Arithmetic-functions"></a>

  83. <h4 class="subsection">4.1.1 Arithmetic functions</h4>

  84. 

  85. <dl>

  86. <dt><a name="index-_005f_005fashlsi3"></a>Runtime Function: <em>int</em> <strong>__ashlsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  87. <dt><a name="index-_005f_005fashldi3"></a>Runtime Function: <em>long</em> <strong>__ashldi3</strong> <em>(long <var>a</var>, int <var>b</var>)</em></dt>

  88. <dt><a name="index-_005f_005fashlti3"></a>Runtime Function: <em>long long</em> <strong>__ashlti3</strong> <em>(long long <var>a</var>, int <var>b</var>)</em></dt>

  89. <dd><p>These functions return the result of shifting <var>a</var> left by <var>b</var> bits.

  90. </p></dd></dl>

  91. 

  92. <dl>

  93. <dt><a name="index-_005f_005fashrsi3"></a>Runtime Function: <em>int</em> <strong>__ashrsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  94. <dt><a name="index-_005f_005fashrdi3"></a>Runtime Function: <em>long</em> <strong>__ashrdi3</strong> <em>(long <var>a</var>, int <var>b</var>)</em></dt>

  95. <dt><a name="index-_005f_005fashrti3"></a>Runtime Function: <em>long long</em> <strong>__ashrti3</strong> <em>(long long <var>a</var>, int <var>b</var>)</em></dt>

  96. <dd><p>These functions return the result of arithmetically shifting <var>a</var> right

  97. by <var>b</var> bits.

  98. </p></dd></dl>

  99. 

  100. <dl>

  101. <dt><a name="index-_005f_005fdivsi3"></a>Runtime Function: <em>int</em> <strong>__divsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  102. <dt><a name="index-_005f_005fdivdi3"></a>Runtime Function: <em>long</em> <strong>__divdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  103. <dt><a name="index-_005f_005fdivti3"></a>Runtime Function: <em>long long</em> <strong>__divti3</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>

  104. <dd><p>These functions return the quotient of the signed division of <var>a</var> and

  105. <var>b</var>.

  106. </p></dd></dl>

  107. 

  108. <dl>

  109. <dt><a name="index-_005f_005flshrsi3"></a>Runtime Function: <em>int</em> <strong>__lshrsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  110. <dt><a name="index-_005f_005flshrdi3"></a>Runtime Function: <em>long</em> <strong>__lshrdi3</strong> <em>(long <var>a</var>, int <var>b</var>)</em></dt>

  111. <dt><a name="index-_005f_005flshrti3"></a>Runtime Function: <em>long long</em> <strong>__lshrti3</strong> <em>(long long <var>a</var>, int <var>b</var>)</em></dt>

  112. <dd><p>These functions return the result of logically shifting <var>a</var> right by

  113. <var>b</var> bits.

  114. </p></dd></dl>

  115. 

  116. <dl>

  117. <dt><a name="index-_005f_005fmodsi3"></a>Runtime Function: <em>int</em> <strong>__modsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  118. <dt><a name="index-_005f_005fmoddi3"></a>Runtime Function: <em>long</em> <strong>__moddi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  119. <dt><a name="index-_005f_005fmodti3"></a>Runtime Function: <em>long long</em> <strong>__modti3</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>

  120. <dd><p>These functions return the remainder of the signed division of <var>a</var>

  121. and <var>b</var>.

  122. </p></dd></dl>

  123. 

  124. <dl>

  125. <dt><a name="index-_005f_005fmulsi3"></a>Runtime Function: <em>int</em> <strong>__mulsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  126. <dt><a name="index-_005f_005fmuldi3"></a>Runtime Function: <em>long</em> <strong>__muldi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  127. <dt><a name="index-_005f_005fmulti3"></a>Runtime Function: <em>long long</em> <strong>__multi3</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>

  128. <dd><p>These functions return the product of <var>a</var> and <var>b</var>.

  129. </p></dd></dl>

  130. 

  131. <dl>

  132. <dt><a name="index-_005f_005fnegdi2"></a>Runtime Function: <em>long</em> <strong>__negdi2</strong> <em>(long <var>a</var>)</em></dt>

  133. <dt><a name="index-_005f_005fnegti2"></a>Runtime Function: <em>long long</em> <strong>__negti2</strong> <em>(long long <var>a</var>)</em></dt>

  134. <dd><p>These functions return the negation of <var>a</var>.

  135. </p></dd></dl>

  136. 

  137. <dl>

  138. <dt><a name="index-_005f_005fudivsi3"></a>Runtime Function: <em>unsigned int</em> <strong>__udivsi3</strong> <em>(unsigned int <var>a</var>, unsigned int <var>b</var>)</em></dt>

  139. <dt><a name="index-_005f_005fudivdi3"></a>Runtime Function: <em>unsigned long</em> <strong>__udivdi3</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>)</em></dt>

  140. <dt><a name="index-_005f_005fudivti3"></a>Runtime Function: <em>unsigned long long</em> <strong>__udivti3</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>)</em></dt>

  141. <dd><p>These functions return the quotient of the unsigned division of <var>a</var>

  142. and <var>b</var>.

  143. </p></dd></dl>

  144. 

  145. <dl>

  146. <dt><a name="index-_005f_005fudivmoddi4"></a>Runtime Function: <em>unsigned long</em> <strong>__udivmoddi4</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>, unsigned long *<var>c</var>)</em></dt>

  147. <dt><a name="index-_005f_005fudivmodti4"></a>Runtime Function: <em>unsigned long long</em> <strong>__udivmodti4</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>, unsigned long long *<var>c</var>)</em></dt>

  148. <dd><p>These functions calculate both the quotient and remainder of the unsigned

  149. division of <var>a</var> and <var>b</var>.  The return value is the quotient, and

  150. the remainder is placed in variable pointed to by <var>c</var>.

  151. </p></dd></dl>

  152. 

  153. <dl>

  154. <dt><a name="index-_005f_005fumodsi3"></a>Runtime Function: <em>unsigned int</em> <strong>__umodsi3</strong> <em>(unsigned int <var>a</var>, unsigned int <var>b</var>)</em></dt>

  155. <dt><a name="index-_005f_005fumoddi3"></a>Runtime Function: <em>unsigned long</em> <strong>__umoddi3</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>)</em></dt>

  156. <dt><a name="index-_005f_005fumodti3"></a>Runtime Function: <em>unsigned long long</em> <strong>__umodti3</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>)</em></dt>

  157. <dd><p>These functions return the remainder of the unsigned division of <var>a</var>

  158. and <var>b</var>.

  159. </p></dd></dl>

  160. 

  161. <a name="Comparison-functions"></a>

  162. <h4 class="subsection">4.1.2 Comparison functions</h4>

  163. 

  164. <p>The following functions implement integral comparisons.  These functions

  165. implement a low-level compare, upon which the higher level comparison

  166. operators (such as less than and greater than or equal to) can be

  167. constructed.  The returned values lie in the range zero to two, to allow

  168. the high-level operators to be implemented by testing the returned

  169. result using either signed or unsigned comparison.

  170. </p>

  171. <dl>

  172. <dt><a name="index-_005f_005fcmpdi2"></a>Runtime Function: <em>int</em> <strong>__cmpdi2</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  173. <dt><a name="index-_005f_005fcmpti2"></a>Runtime Function: <em>int</em> <strong>__cmpti2</strong> <em>(long long <var>a</var>, long long <var>b</var>)</em></dt>

  174. <dd><p>These functions perform a signed comparison of <var>a</var> and <var>b</var>.  If

  175. <var>a</var> is less than <var>b</var>, they return 0; if <var>a</var> is greater than

  176. <var>b</var>, they return 2; and if <var>a</var> and <var>b</var> are equal they return 1.

  177. </p></dd></dl>

  178. 

  179. <dl>

  180. <dt><a name="index-_005f_005fucmpdi2"></a>Runtime Function: <em>int</em> <strong>__ucmpdi2</strong> <em>(unsigned long <var>a</var>, unsigned long <var>b</var>)</em></dt>

  181. <dt><a name="index-_005f_005fucmpti2"></a>Runtime Function: <em>int</em> <strong>__ucmpti2</strong> <em>(unsigned long long <var>a</var>, unsigned long long <var>b</var>)</em></dt>

  182. <dd><p>These functions perform an unsigned comparison of <var>a</var> and <var>b</var>.

  183. If <var>a</var> is less than <var>b</var>, they return 0; if <var>a</var> is greater than

  184. <var>b</var>, they return 2; and if <var>a</var> and <var>b</var> are equal they return 1.

  185. </p></dd></dl>

  186. 

  187. <a name="Trapping-arithmetic-functions"></a>

  188. <h4 class="subsection">4.1.3 Trapping arithmetic functions</h4>

  189. 

  190. <p>The following functions implement trapping arithmetic.  These functions

  191. call the libc function <code>abort</code> upon signed arithmetic overflow.

  192. </p>

  193. <dl>

  194. <dt><a name="index-_005f_005fabsvsi2"></a>Runtime Function: <em>int</em> <strong>__absvsi2</strong> <em>(int <var>a</var>)</em></dt>

  195. <dt><a name="index-_005f_005fabsvdi2"></a>Runtime Function: <em>long</em> <strong>__absvdi2</strong> <em>(long <var>a</var>)</em></dt>

  196. <dd><p>These functions return the absolute value of <var>a</var>.

  197. </p></dd></dl>

  198. 

  199. <dl>

  200. <dt><a name="index-_005f_005faddvsi3"></a>Runtime Function: <em>int</em> <strong>__addvsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  201. <dt><a name="index-_005f_005faddvdi3"></a>Runtime Function: <em>long</em> <strong>__addvdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  202. <dd><p>These functions return the sum of <var>a</var> and <var>b</var>; that is

  203. <code><var>a</var> + <var>b</var></code>.

  204. </p></dd></dl>

  205. 

  206. <dl>

  207. <dt><a name="index-_005f_005fmulvsi3"></a>Runtime Function: <em>int</em> <strong>__mulvsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  208. <dt><a name="index-_005f_005fmulvdi3"></a>Runtime Function: <em>long</em> <strong>__mulvdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  209. <dd><p>The functions return the product of <var>a</var> and <var>b</var>; that is

  210. <code><var>a</var> * <var>b</var></code>.

  211. </p></dd></dl>

  212. 

  213. <dl>

  214. <dt><a name="index-_005f_005fnegvsi2"></a>Runtime Function: <em>int</em> <strong>__negvsi2</strong> <em>(int <var>a</var>)</em></dt>

  215. <dt><a name="index-_005f_005fnegvdi2"></a>Runtime Function: <em>long</em> <strong>__negvdi2</strong> <em>(long <var>a</var>)</em></dt>

  216. <dd><p>These functions return the negation of <var>a</var>; that is <code>-<var>a</var></code>.

  217. </p></dd></dl>

  218. 

  219. <dl>

  220. <dt><a name="index-_005f_005fsubvsi3"></a>Runtime Function: <em>int</em> <strong>__subvsi3</strong> <em>(int <var>a</var>, int <var>b</var>)</em></dt>

  221. <dt><a name="index-_005f_005fsubvdi3"></a>Runtime Function: <em>long</em> <strong>__subvdi3</strong> <em>(long <var>a</var>, long <var>b</var>)</em></dt>

  222. <dd><p>These functions return the difference between <var>b</var> and <var>a</var>;

  223. that is <code><var>a</var> - <var>b</var></code>.

  224. </p></dd></dl>

  225. 

  226. <a name="Bit-operations"></a>

  227. <h4 class="subsection">4.1.4 Bit operations</h4>

  228. 

  229. <dl>

  230. <dt><a name="index-_005f_005fclzsi2"></a>Runtime Function: <em>int</em> <strong>__clzsi2</strong> <em>(unsigned int <var>a</var>)</em></dt>

  231. <dt><a name="index-_005f_005fclzdi2"></a>Runtime Function: <em>int</em> <strong>__clzdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>

  232. <dt><a name="index-_005f_005fclzti2"></a>Runtime Function: <em>int</em> <strong>__clzti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>

  233. <dd><p>These functions return the number of leading 0-bits in <var>a</var>, starting

  234. at the most significant bit position.  If <var>a</var> is zero, the result is

  235. undefined.

  236. </p></dd></dl>

  237. 

  238. <dl>

  239. <dt><a name="index-_005f_005fctzsi2"></a>Runtime Function: <em>int</em> <strong>__ctzsi2</strong> <em>(unsigned int <var>a</var>)</em></dt>

  240. <dt><a name="index-_005f_005fctzdi2"></a>Runtime Function: <em>int</em> <strong>__ctzdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>

  241. <dt><a name="index-_005f_005fctzti2"></a>Runtime Function: <em>int</em> <strong>__ctzti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>

  242. <dd><p>These functions return the number of trailing 0-bits in <var>a</var>, starting

  243. at the least significant bit position.  If <var>a</var> is zero, the result is

  244. undefined.

  245. </p></dd></dl>

  246. 

  247. <dl>

  248. <dt><a name="index-_005f_005fffsdi2"></a>Runtime Function: <em>int</em> <strong>__ffsdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>

  249. <dt><a name="index-_005f_005fffsti2"></a>Runtime Function: <em>int</em> <strong>__ffsti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>

  250. <dd><p>These functions return the index of the least significant 1-bit in <var>a</var>,

  251. or the value zero if <var>a</var> is zero.  The least significant bit is index

  252. one.

  253. </p></dd></dl>

  254. 

  255. <dl>

  256. <dt><a name="index-_005f_005fparitysi2"></a>Runtime Function: <em>int</em> <strong>__paritysi2</strong> <em>(unsigned int <var>a</var>)</em></dt>

  257. <dt><a name="index-_005f_005fparitydi2"></a>Runtime Function: <em>int</em> <strong>__paritydi2</strong> <em>(unsigned long <var>a</var>)</em></dt>

  258. <dt><a name="index-_005f_005fparityti2"></a>Runtime Function: <em>int</em> <strong>__parityti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>

  259. <dd><p>These functions return the value zero if the number of bits set in

  260. <var>a</var> is even, and the value one otherwise.

  261. </p></dd></dl>

  262. 

  263. <dl>

  264. <dt><a name="index-_005f_005fpopcountsi2"></a>Runtime Function: <em>int</em> <strong>__popcountsi2</strong> <em>(unsigned int <var>a</var>)</em></dt>

  265. <dt><a name="index-_005f_005fpopcountdi2"></a>Runtime Function: <em>int</em> <strong>__popcountdi2</strong> <em>(unsigned long <var>a</var>)</em></dt>

  266. <dt><a name="index-_005f_005fpopcountti2"></a>Runtime Function: <em>int</em> <strong>__popcountti2</strong> <em>(unsigned long long <var>a</var>)</em></dt>

  267. <dd><p>These functions return the number of bits set in <var>a</var>.

  268. </p></dd></dl>

  269. 

  270. <dl>

  271. <dt><a name="index-_005f_005fbswapsi2"></a>Runtime Function: <em>int32_t</em> <strong>__bswapsi2</strong> <em>(int32_t <var>a</var>)</em></dt>

  272. <dt><a name="index-_005f_005fbswapdi2"></a>Runtime Function: <em>int64_t</em> <strong>__bswapdi2</strong> <em>(int64_t <var>a</var>)</em></dt>

  273. <dd><p>These functions return the <var>a</var> byteswapped.

  274. </p></dd></dl>

  275. 

  276. <hr>

  277. <div class="header">

  278. <p>

  279. Next: <a href="Soft-float-library-routines.html#Soft-float-library-routines" accesskey="n" rel="next">Soft float library routines</a>, Up: <a href="Libgcc.html#Libgcc" accesskey="u" rel="up">Libgcc</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>

  280. </div>

  281. 

  282. 

  283. 

  284. </body>

  285. </html>