visus
/
toolchain-gcc-arm-embedded
Vērot 1
Pievienot zvaigznīti 0
Atdalīts 0
Kods Problēmas 0 Izmaiņu pieprasījumi 0 Laidieni 0 Vikivietne Aktivitāte
Nevar pievienot vairāk kā 25 tēmas Tēmai ir jāsākas ar burtu vai ciparu, tā var saturēt domu zīmes ('-') un var būt līdz 35 simboliem gara.
2 Revīzijas
1 Atzars
Atzars: main
Atzari Tagi
${ item.name }
Izveidot atzaru ${ searchTerm }
no 'main'
${ noResults }
toolchain-gcc-arm-embedded/share/doc/gcc-arm-none-eabi/html/gccint/Named-Address-Spaces.html

211 rindas
11KB
Neapstrādāts Patstāvīgā saite Vainot Vēsture 

  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

  2. <html>

  3. <!-- Copyright (C) 1988-2020 Free Software Foundation, Inc.

  4. 

  5. Permission is granted to copy, distribute and/or modify this document

  6. under the terms of the GNU Free Documentation License, Version 1.3 or

  7. any later version published by the Free Software Foundation; with the

  8. Invariant Sections being "Funding Free Software", the Front-Cover

  9. Texts being (a) (see below), and with the Back-Cover Texts being (b)

  10. (see below).  A copy of the license is included in the section entitled

  11. "GNU Free Documentation License".

  12. 

  13. (a) The FSF's Front-Cover Text is:

  14. 

  15. A GNU Manual

  16. 

  17. (b) The FSF's Back-Cover Text is:

  18. 

  19. You have freedom to copy and modify this GNU Manual, like GNU

  20.      software.  Copies published by the Free Software Foundation raise

  21.      funds for GNU development. -->

  22. <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->

  23. <head>

  24. <meta http-equiv="Content-Type" content="text/html; charset=utf-8">

  25. <title>Named Address Spaces (GNU Compiler Collection (GCC) Internals)</title>

  26. 

  27. <meta name="description" content="Named Address Spaces (GNU Compiler Collection (GCC) Internals)">

  28. <meta name="keywords" content="Named Address Spaces (GNU Compiler Collection (GCC) Internals)">

  29. <meta name="resource-type" content="document">

  30. <meta name="distribution" content="global">

  31. <meta name="Generator" content="makeinfo">

  32. <link href="index.html#Top" rel="start" title="Top">

  33. <link href="Option-Index.html#Option-Index" rel="index" title="Option Index">

  34. <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">

  35. <link href="Target-Macros.html#Target-Macros" rel="up" title="Target Macros">

  36. <link href="Misc.html#Misc" rel="next" title="Misc">

  37. <link href="D-Language-and-ABI.html#D-Language-and-ABI" rel="prev" title="D Language and ABI">

  38. <style type="text/css">

  39. <!--

  40. a.summary-letter {text-decoration: none}

  41. blockquote.indentedblock {margin-right: 0em}

  42. blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}

  43. blockquote.smallquotation {font-size: smaller}

  44. div.display {margin-left: 3.2em}

  45. div.example {margin-left: 3.2em}

  46. div.lisp {margin-left: 3.2em}

  47. div.smalldisplay {margin-left: 3.2em}

  48. div.smallexample {margin-left: 3.2em}

  49. div.smalllisp {margin-left: 3.2em}

  50. kbd {font-style: oblique}

  51. pre.display {font-family: inherit}

  52. pre.format {font-family: inherit}

  53. pre.menu-comment {font-family: serif}

  54. pre.menu-preformatted {font-family: serif}

  55. pre.smalldisplay {font-family: inherit; font-size: smaller}

  56. pre.smallexample {font-size: smaller}

  57. pre.smallformat {font-family: inherit; font-size: smaller}

  58. pre.smalllisp {font-size: smaller}

  59. span.nolinebreak {white-space: nowrap}

  60. span.roman {font-family: initial; font-weight: normal}

  61. span.sansserif {font-family: sans-serif; font-weight: normal}

  62. ul.no-bullet {list-style: none}

  63. -->

  64. </style>

  65. 

  66. 

  67. </head>

  68. 

  69. <body lang="en">

  70. <a name="Named-Address-Spaces"></a>

  71. <div class="header">

  72. <p>

  73. Next: <a href="Misc.html#Misc" accesskey="n" rel="next">Misc</a>, Previous: <a href="D-Language-and-ABI.html#D-Language-and-ABI" accesskey="p" rel="prev">D Language and ABI</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</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="Adding-support-for-named-address-spaces"></a>

  77. <h3 class="section">18.30 Adding support for named address spaces</h3>

  78. <a name="index-named-address-spaces"></a>

  79. 

  80. <p>The draft technical report of the ISO/IEC JTC1 S22 WG14 N1275

  81. standards committee, <cite>Programming Languages - C - Extensions to

  82. support embedded processors</cite>, specifies a syntax for embedded

  83. processors to specify alternate address spaces.  You can configure a

  84. GCC port to support section 5.1 of the draft report to add support for

  85. address spaces other than the default address space.  These address

  86. spaces are new keywords that are similar to the <code>volatile</code> and

  87. <code>const</code> type attributes.

  88. </p>

  89. <p>Pointers to named address spaces can have a different size than

  90. pointers to the generic address space.

  91. </p>

  92. <p>For example, the SPU port uses the <code>__ea</code> address space to refer

  93. to memory in the host processor, rather than memory local to the SPU

  94. processor.  Access to memory in the <code>__ea</code> address space involves

  95. issuing DMA operations to move data between the host processor and the

  96. local processor memory address space.  Pointers in the <code>__ea</code>

  97. address space are either 32 bits or 64 bits based on the

  98. <samp>-mea32</samp> or <samp>-mea64</samp> switches (native SPU pointers are

  99. always 32 bits).

  100. </p>

  101. <p>Internally, address spaces are represented as a small integer in the

  102. range 0 to 15 with address space 0 being reserved for the generic

  103. address space.

  104. </p>

  105. <p>To register a named address space qualifier keyword with the C front end,

  106. the target may call the <code>c_register_addr_space</code> routine.  For example,

  107. the SPU port uses the following to declare <code>__ea</code> as the keyword for

  108. named address space #1:

  109. </p><div class="smallexample">

  110. <pre class="smallexample">#define ADDR_SPACE_EA 1

  111. c_register_addr_space (&quot;__ea&quot;, ADDR_SPACE_EA);

  112. </pre></div>

  113. 

  114. <dl>

  115. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fPOINTER_005fMODE"></a>Target Hook: <em>scalar_int_mode</em> <strong>TARGET_ADDR_SPACE_POINTER_MODE</strong> <em>(addr_space_t <var>address_space</var>)</em></dt>

  116. <dd><p>Define this to return the machine mode to use for pointers to

  117. <var>address_space</var> if the target supports named address spaces.

  118. The default version of this hook returns <code>ptr_mode</code>.

  119. </p></dd></dl>

  120. 

  121. <dl>

  122. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fADDRESS_005fMODE"></a>Target Hook: <em>scalar_int_mode</em> <strong>TARGET_ADDR_SPACE_ADDRESS_MODE</strong> <em>(addr_space_t <var>address_space</var>)</em></dt>

  123. <dd><p>Define this to return the machine mode to use for addresses in

  124. <var>address_space</var> if the target supports named address spaces.

  125. The default version of this hook returns <code>Pmode</code>.

  126. </p></dd></dl>

  127. 

  128. <dl>

  129. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fVALID_005fPOINTER_005fMODE"></a>Target Hook: <em>bool</em> <strong>TARGET_ADDR_SPACE_VALID_POINTER_MODE</strong> <em>(scalar_int_mode <var>mode</var>, addr_space_t <var>as</var>)</em></dt>

  130. <dd><p>Define this to return nonzero if the port can handle pointers

  131. with machine mode <var>mode</var> to address space <var>as</var>.  This target

  132. hook is the same as the <code>TARGET_VALID_POINTER_MODE</code> target hook,

  133. except that it includes explicit named address space support.  The default

  134. version of this hook returns true for the modes returned by either the

  135. <code>TARGET_ADDR_SPACE_POINTER_MODE</code> or <code>TARGET_ADDR_SPACE_ADDRESS_MODE</code>

  136. target hooks for the given address space.

  137. </p></dd></dl>

  138. 

  139. <dl>

  140. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fLEGITIMATE_005fADDRESS_005fP"></a>Target Hook: <em>bool</em> <strong>TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P</strong> <em>(machine_mode <var>mode</var>, rtx <var>exp</var>, bool <var>strict</var>, addr_space_t <var>as</var>)</em></dt>

  141. <dd><p>Define this to return true if <var>exp</var> is a valid address for mode

  142. <var>mode</var> in the named address space <var>as</var>.  The <var>strict</var>

  143. parameter says whether strict addressing is in effect after reload has

  144. finished.  This target hook is the same as the

  145. <code>TARGET_LEGITIMATE_ADDRESS_P</code> target hook, except that it includes

  146. explicit named address space support.

  147. </p></dd></dl>

  148. 

  149. <dl>

  150. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fLEGITIMIZE_005fADDRESS"></a>Target Hook: <em>rtx</em> <strong>TARGET_ADDR_SPACE_LEGITIMIZE_ADDRESS</strong> <em>(rtx <var>x</var>, rtx <var>oldx</var>, machine_mode <var>mode</var>, addr_space_t <var>as</var>)</em></dt>

  151. <dd><p>Define this to modify an invalid address <var>x</var> to be a valid address

  152. with mode <var>mode</var> in the named address space <var>as</var>.  This target

  153. hook is the same as the <code>TARGET_LEGITIMIZE_ADDRESS</code> target hook,

  154. except that it includes explicit named address space support.

  155. </p></dd></dl>

  156. 

  157. <dl>

  158. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fSUBSET_005fP"></a>Target Hook: <em>bool</em> <strong>TARGET_ADDR_SPACE_SUBSET_P</strong> <em>(addr_space_t <var>subset</var>, addr_space_t <var>superset</var>)</em></dt>

  159. <dd><p>Define this to return whether the <var>subset</var> named address space is

  160. contained within the <var>superset</var> named address space.  Pointers to

  161. a named address space that is a subset of another named address space

  162. will be converted automatically without a cast if used together in

  163. arithmetic operations.  Pointers to a superset address space can be

  164. converted to pointers to a subset address space via explicit casts.

  165. </p></dd></dl>

  166. 

  167. <dl>

  168. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fZERO_005fADDRESS_005fVALID"></a>Target Hook: <em>bool</em> <strong>TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID</strong> <em>(addr_space_t <var>as</var>)</em></dt>

  169. <dd><p>Define this to modify the default handling of address 0 for the

  170. address space.  Return true if 0 should be considered a valid address.

  171. </p></dd></dl>

  172. 

  173. <dl>

  174. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fCONVERT"></a>Target Hook: <em>rtx</em> <strong>TARGET_ADDR_SPACE_CONVERT</strong> <em>(rtx <var>op</var>, tree <var>from_type</var>, tree <var>to_type</var>)</em></dt>

  175. <dd><p>Define this to convert the pointer expression represented by the RTL

  176. <var>op</var> with type <var>from_type</var> that points to a named address

  177. space to a new pointer expression with type <var>to_type</var> that points

  178. to a different named address space.  When this hook it called, it is

  179. guaranteed that one of the two address spaces is a subset of the other,

  180. as determined by the <code>TARGET_ADDR_SPACE_SUBSET_P</code> target hook.

  181. </p></dd></dl>

  182. 

  183. <dl>

  184. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fDEBUG"></a>Target Hook: <em>int</em> <strong>TARGET_ADDR_SPACE_DEBUG</strong> <em>(addr_space_t <var>as</var>)</em></dt>

  185. <dd><p>Define this to define how the address space is encoded in dwarf.

  186. The result is the value to be used with <code>DW_AT_address_class</code>.

  187. </p></dd></dl>

  188. 

  189. <dl>

  190. <dt><a name="index-TARGET_005fADDR_005fSPACE_005fDIAGNOSE_005fUSAGE"></a>Target Hook: <em>void</em> <strong>TARGET_ADDR_SPACE_DIAGNOSE_USAGE</strong> <em>(addr_space_t <var>as</var>, location_t <var>loc</var>)</em></dt>

  191. <dd><p>Define this hook if the availability of an address space depends on

  192. command line options and some diagnostics should be printed when the

  193. address space is used.  This hook is called during parsing and allows

  194. to emit a better diagnostic compared to the case where the address space

  195. was not registered with <code>c_register_addr_space</code>.  <var>as</var> is

  196. the address space as registered with <code>c_register_addr_space</code>.

  197. <var>loc</var> is the location of the address space qualifier token.

  198. The default implementation does nothing.

  199. </p></dd></dl>

  200. 

  201. <hr>

  202. <div class="header">

  203. <p>

  204. Next: <a href="Misc.html#Misc" accesskey="n" rel="next">Misc</a>, Previous: <a href="D-Language-and-ABI.html#D-Language-and-ABI" accesskey="p" rel="prev">D Language and ABI</a>, Up: <a href="Target-Macros.html#Target-Macros" accesskey="u" rel="up">Target Macros</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>

  205. </div>

  206. 

  207. 

  208. 

  209. </body>

  210. </html>