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64<h1 class="settitle" align="center">Host/Target specific installation notes for GCC</h1>
65
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89<a name="index-Specific"></a>
90<a name="index-Specific-installation-notes"></a>
91<a name="index-Target-specific-installation"></a>
92<a name="index-Host-specific-installation"></a>
93<a name="index-Target-specific-installation-notes"></a>
94
95<p>Please read this document carefully <em>before</em> installing the
96GNU Compiler Collection on your machine.
97</p>
98<p>Note that this list of install notes is <em>not</em> a list of supported
99hosts or targets.  Not all supported hosts and targets are listed
100here, only the ones that require host-specific or target-specific
101information have to.
102</p>
103<ul>
104<li> <a href="#aarch64-x-x">aarch64*-*-*</a>
105</li><li> <a href="#alpha-x-x">alpha*-*-*</a>
106</li><li> <a href="#amd64-x-solaris2">amd64-*-solaris2*</a>
107</li><li> <a href="#arm-x-eabi">arm-*-eabi</a>
108</li><li> <a href="#avr">avr</a>
109</li><li> <a href="#bfin">Blackfin</a>
110</li><li> <a href="#dos">DOS</a>
111</li><li> <a href="#x-x-freebsd">*-*-freebsd*</a>
112</li><li> <a href="#h8300-hms">h8300-hms</a>
113</li><li> <a href="#hppa-hp-hpux">hppa*-hp-hpux*</a>
114</li><li> <a href="#hppa-hp-hpux10">hppa*-hp-hpux10</a>
115</li><li> <a href="#hppa-hp-hpux11">hppa*-hp-hpux11</a>
116</li><li> <a href="#x-x-linux-gnu">*-*-linux-gnu</a>
117</li><li> <a href="#ix86-x-linux">i?86-*-linux*</a>
118</li><li> <a href="#ix86-x-solaris2">i?86-*-solaris2*</a>
119</li><li> <a href="#ia64-x-linux">ia64-*-linux</a>
120</li><li> <a href="#ia64-x-hpux">ia64-*-hpux*</a>
121</li><li> <a href="#x-ibm-aix">*-ibm-aix*</a>
122</li><li> <a href="#iq2000-x-elf">iq2000-*-elf</a>
123</li><li> <a href="#lm32-x-elf">lm32-*-elf</a>
124</li><li> <a href="#lm32-x-uclinux">lm32-*-uclinux</a>
125</li><li> <a href="#m32c-x-elf">m32c-*-elf</a>
126</li><li> <a href="#m32r-x-elf">m32r-*-elf</a>
127</li><li> <a href="#m68k-x-x">m68k-*-*</a>
128</li><li> <a href="#m68k-uclinux">m68k-uclinux</a>
129</li><li> <a href="#microblaze-x-elf">microblaze-*-elf</a>
130</li><li> <a href="#mips-x-x">mips-*-*</a>
131</li><li> <a href="#nds32le-x-elf">nds32le-*-elf</a>
132</li><li> <a href="#nds32be-x-elf">nds32be-*-elf</a>
133</li><li> <a href="#nvptx-x-none">nvptx-*-none</a>
134</li><li> <a href="#or1k-x-elf">or1k-*-elf</a>
135</li><li> <a href="#or1k-x-linux">or1k-*-linux</a>
136</li><li> <a href="#powerpc-x-x">powerpc*-*-*</a>
137</li><li> <a href="#powerpc-x-darwin">powerpc-*-darwin*</a>
138</li><li> <a href="#powerpc-x-elf">powerpc-*-elf</a>
139</li><li> <a href="#powerpc-x-linux-gnu">powerpc*-*-linux-gnu*</a>
140</li><li> <a href="#powerpc-x-netbsd">powerpc-*-netbsd*</a>
141</li><li> <a href="#powerpc-x-eabisim">powerpc-*-eabisim</a>
142</li><li> <a href="#powerpc-x-eabi">powerpc-*-eabi</a>
143</li><li> <a href="#powerpcle-x-elf">powerpcle-*-elf</a>
144</li><li> <a href="#powerpcle-x-eabisim">powerpcle-*-eabisim</a>
145</li><li> <a href="#powerpcle-x-eabi">powerpcle-*-eabi</a>
146</li><li> <a href="#riscv32-x-elf">riscv32-*-elf</a>
147</li><li> <a href="#riscv32-x-linux">riscv32-*-linux</a>
148</li><li> <a href="#riscv64-x-elf">riscv64-*-elf</a>
149</li><li> <a href="#riscv64-x-linux">riscv64-*-linux</a>
150</li><li> <a href="#s390-x-linux">s390-*-linux*</a>
151</li><li> <a href="#s390x-x-linux">s390x-*-linux*</a>
152</li><li> <a href="#s390x-ibm-tpf">s390x-ibm-tpf*</a>
153</li><li> <a href="#x-x-solaris2">*-*-solaris2*</a>
154</li><li> <a href="#sparc-x-x">sparc*-*-*</a>
155</li><li> <a href="#sparc-sun-solaris2">sparc-sun-solaris2*</a>
156</li><li> <a href="#sparc-x-linux">sparc-*-linux*</a>
157</li><li> <a href="#sparc64-x-solaris2">sparc64-*-solaris2*</a>
158</li><li> <a href="#sparcv9-x-solaris2">sparcv9-*-solaris2*</a>
159</li><li> <a href="#c6x-x-x">c6x-*-*</a>
160</li><li> <a href="#tilegx-x-linux">tilegx-*-linux*</a>
161</li><li> <a href="#tilegxbe-x-linux">tilegxbe-*-linux*</a>
162</li><li> <a href="#tilepro-x-linux">tilepro-*-linux*</a>
163</li><li> <a href="#visium-x-elf">visium-*-elf</a>
164</li><li> <a href="#x-x-vxworks">*-*-vxworks*</a>
165</li><li> <a href="#x86-64-x-x">x86_64-*-*, amd64-*-*</a>
166</li><li> <a href="#x86-64-x-solaris2">x86_64-*-solaris2*</a>
167</li><li> <a href="#xtensa-x-elf">xtensa*-*-elf</a>
168</li><li> <a href="#xtensa-x-linux">xtensa*-*-linux*</a>
169</li><li> <a href="#windows">Microsoft Windows</a>
170</li><li> <a href="#x-x-cygwin">*-*-cygwin</a>
171</li><li> <a href="#x-x-mingw32">*-*-mingw32</a>
172</li><li> <a href="#os2">OS/2</a>
173</li><li> <a href="#older">Older systems</a>
174</li></ul>
175
176<ul>
177<li> <a href="#elf">all ELF targets</a> (SVR4, Solaris 2, etc.)
178</li></ul>
179
180
181<!-- -------- host/target specific issues start here ---------------- -->
182<hr />
183<a name="aarch64-x-x"></a><a name="aarch64*-*-*"></a>
184<h3 class="heading">aarch64*-*-*</h3>
185<p>Binutils pre 2.24 does not have support for selecting <samp>-mabi</samp> and
186does not support ILP32.  If it is used to build GCC 4.9 or later, GCC will
187not support option <samp>-mabi=ilp32</samp>.
188</p>
189<p>To enable a workaround for the Cortex-A53 erratum number 835769 by default
190(for all CPUs regardless of -mcpu option given) at configure time use the
191<samp>--enable-fix-cortex-a53-835769</samp> option.  This will enable the fix by
192default and can be explicitly disabled during compilation by passing the
193<samp>-mno-fix-cortex-a53-835769</samp> option.  Conversely,
194<samp>--disable-fix-cortex-a53-835769</samp> will disable the workaround by
195default.  The workaround is disabled by default if neither of
196<samp>--enable-fix-cortex-a53-835769</samp> or
197<samp>--disable-fix-cortex-a53-835769</samp> is given at configure time.
198</p>
199<p>To enable a workaround for the Cortex-A53 erratum number 843419 by default
200(for all CPUs regardless of -mcpu option given) at configure time use the
201<samp>--enable-fix-cortex-a53-843419</samp> option.  This workaround is applied at
202link time.  Enabling the workaround will cause GCC to pass the relevant option
203to the linker.  It can be explicitly disabled during compilation by passing the
204<samp>-mno-fix-cortex-a53-843419</samp> option.  Conversely,
205<samp>--disable-fix-cortex-a53-843419</samp> will disable the workaround by default.
206The workaround is disabled by default if neither of
207<samp>--enable-fix-cortex-a53-843419</samp> or
208<samp>--disable-fix-cortex-a53-843419</samp> is given at configure time.
209</p>
210<p>To enable Branch Target Identification Mechanism and Return Address Signing by
211default at configure time use the <samp>--enable-standard-branch-protection</samp>
212option.  This is equivalent to having <samp>-mbranch-protection=standard</samp>
213during compilation.  This can be explicitly disabled during compilation by
214passing the <samp>-mbranch-protection=none</samp> option which turns off all
215types of branch protections.  Conversely,
216<samp>--disable-standard-branch-protection</samp> will disable both the
217protections by default.  This mechanism is turned off by default if neither
218of the options are given at configure time.
219</p>
220<hr />
221<a name="alpha-x-x"></a><a name="alpha*-*-*"></a>
222<h3 class="heading">alpha*-*-*</h3>
223<p>This section contains general configuration information for all
224Alpha-based platforms using ELF.  In addition to reading this
225section, please read all other sections that match your target.
226</p>
227<hr />
228<a name="amd64-x-solaris2"></a><a name="amd64-*-solaris2*"></a>
229<h3 class="heading">amd64-*-solaris2*</h3>
230<p>This is a synonym for &lsquo;<samp>x86_64-*-solaris2*</samp>&rsquo;.
231</p>
232<hr />
233<a name="amdgcn-x-amdhsa"></a><a name="amdgcn-*-amdhsa"></a>
234<h3 class="heading">amdgcn-*-amdhsa</h3>
235<p>AMD GCN GPU target.
236</p>
237<p>Instead of GNU Binutils, you will need to install LLVM 6, or later, and copy
238<samp>bin/llvm-mc</samp> to <samp>amdgcn-amdhsa/bin/as</samp>,
239<samp>bin/lld</samp> to <samp>amdgcn-amdhsa/bin/ld</samp>,
240<samp>bin/llvm-nm</samp> to <samp>amdgcn-amdhsa/bin/nm</samp>, and
241<samp>bin/llvm-ar</samp> to both <samp>bin/amdgcn-amdhsa-ar</samp> and
242<samp>bin/amdgcn-amdhsa-ranlib</samp>.
243</p>
244<p>Use Newlib (2019-01-16, or newer).
245</p>
246<p>To run the binaries, install the HSA Runtime from the
247<a href="https://rocm.github.io">ROCm Platform</a>, and use
248<samp>libexec/gcc/amdhsa-amdhsa/<var>version</var>/gcn-run</samp> to launch them
249on the GPU.
250</p>
251<hr />
252<a name="arc-x-elf32"></a><a name="arc-*-elf32"></a>
253<h3 class="heading">arc-*-elf32</h3>
254
255<p>Use &lsquo;<samp>configure --target=arc-elf32 --with-cpu=<var>cpu</var> --enable-languages=&quot;c,c++&quot;</samp>&rsquo;
256to configure GCC, with <var>cpu</var> being one of &lsquo;<samp>arc600</samp>&rsquo;, &lsquo;<samp>arc601</samp>&rsquo;,
257or &lsquo;<samp>arc700</samp>&rsquo;.
258</p>
259<hr />
260<a name="arc-linux-uclibc"></a><a name="arc-linux-uclibc-1"></a>
261<h3 class="heading">arc-linux-uclibc</h3>
262
263<p>Use &lsquo;<samp>configure --target=arc-linux-uclibc --with-cpu=arc700 --enable-languages=&quot;c,c++&quot;</samp>&rsquo; to configure GCC.
264</p>
265<hr />
266<a name="arm-x-eabi"></a><a name="arm-*-eabi"></a>
267<h3 class="heading">arm-*-eabi</h3>
268<p>ARM-family processors.
269</p>
270<p>Building the Ada frontend commonly fails (an infinite loop executing
271<code>xsinfo</code>) if the host compiler is GNAT 4.8.  Host compilers built from the
272GNAT 4.6, 4.9 or 5 release branches are known to succeed.
273</p>
274<hr />
275<a name="avr"></a><a name="avr-1"></a>
276<h3 class="heading">avr</h3>
277<p>ATMEL AVR-family micro controllers.  These are used in embedded
278applications.  There are no standard Unix configurations.
279See &ldquo;AVR Options&rdquo; in the main manual
280for the list of supported MCU types.
281</p>
282<p>Use &lsquo;<samp>configure --target=avr --enable-languages=&quot;c&quot;</samp>&rsquo; to configure GCC.
283</p>
284<p>Further installation notes and other useful information about AVR tools
285can also be obtained from:
286</p>
287<ul>
288<li> <a href="http://www.nongnu.org/avr/">http://www.nongnu.org/avr/</a>
289</li><li> <a href="http://www.amelek.gda.pl/avr/">http://www.amelek.gda.pl/avr/</a>
290</li></ul>
291
292<p>The following error:
293</p><div class="smallexample">
294<pre class="smallexample">Error: register required
295</pre></div>
296
297<p>indicates that you should upgrade to a newer version of the binutils.
298</p>
299<hr />
300<a name="bfin"></a><a name="Blackfin"></a>
301<h3 class="heading">Blackfin</h3>
302<p>The Blackfin processor, an Analog Devices DSP.
303See &ldquo;Blackfin Options&rdquo; in the main manual
304</p>
305<p>More information, and a version of binutils with support for this processor,
306are available at <a href="https://sourceforge.net/projects/adi-toolchain/">https://sourceforge.net/projects/adi-toolchain/</a>.
307</p>
308<hr />
309<a name="cr16"></a><a name="CR16"></a>
310<h3 class="heading">CR16</h3>
311<p>The CR16 CompactRISC architecture is a 16-bit architecture. This
312architecture is used in embedded applications.
313</p>
314
315<p>See &ldquo;CR16 Options&rdquo; in the main manual for a list of CR16-specific options.
316</p>
317<p>Use &lsquo;<samp>configure --target=cr16-elf --enable-languages=c,c++</samp>&rsquo; to configure
318GCC&nbsp;for building a CR16 elf cross-compiler.
319</p>
320<p>Use &lsquo;<samp>configure --target=cr16-uclinux --enable-languages=c,c++</samp>&rsquo; to
321configure GCC&nbsp;for building a CR16 uclinux cross-compiler.
322</p>
323<hr />
324<a name="cris"></a><a name="CRIS"></a>
325<h3 class="heading">CRIS</h3>
326<p>CRIS is the CPU architecture in Axis Communications ETRAX system-on-a-chip
327series.  These are used in embedded applications.
328</p>
329<p>See &ldquo;CRIS Options&rdquo; in the main manual
330for a list of CRIS-specific options.
331</p>
332<p>There are a few different CRIS targets:
333</p><dl compact="compact">
334<dt><code>cris-axis-elf</code></dt>
335<dd><p>Mainly for monolithic embedded systems.  Includes a multilib for the
336&lsquo;<samp>v10</samp>&rsquo; core used in &lsquo;<samp>ETRAX 100 LX</samp>&rsquo;.
337</p></dd>
338<dt><code>cris-axis-linux-gnu</code></dt>
339<dd><p>A GNU/Linux port for the CRIS architecture, currently targeting
340&lsquo;<samp>ETRAX 100 LX</samp>&rsquo; by default.
341</p></dd>
342</dl>
343
344<p>Pre-packaged tools can be obtained from
345<a href="ftp://ftp.axis.com/pub/axis/tools/cris/compiler-kit/">ftp://ftp.axis.com/pub/axis/tools/cris/compiler-kit/</a>.  More
346information about this platform is available at
347<a href="http://developer.axis.com/">http://developer.axis.com/</a>.
348</p>
349<hr />
350<a name="dos"></a><a name="DOS"></a>
351<h3 class="heading">DOS</h3>
352<p>Please have a look at the <a href="binaries.html">binaries page</a>.
353</p>
354<p>You cannot install GCC by itself on MSDOS; it will not compile under
355any MSDOS compiler except itself.  You need to get the complete
356compilation package DJGPP, which includes binaries as well as sources,
357and includes all the necessary compilation tools and libraries.
358</p>
359<hr />
360<a name="epiphany-x-elf"></a><a name="epiphany-*-elf"></a>
361<h3 class="heading">epiphany-*-elf</h3>
362<p>Adapteva Epiphany.
363This configuration is intended for embedded systems.
364</p>
365<hr />
366<a name="x-x-freebsd"></a><a name="g_t*-*-freebsd*"></a>
367<h3 class="heading">*-*-freebsd*</h3>
368<p>Support for FreeBSD 1 was discontinued in GCC 3.2.  Support for
369FreeBSD 2 (and any mutant a.out variants of FreeBSD 3) was
370discontinued in GCC 4.0.
371</p>
372<p>In order to better utilize FreeBSD base system functionality and match
373the configuration of the system compiler, GCC 4.5 and above as well as
374GCC 4.4 past 2010-06-20 leverage SSP support in libc (which is present
375on FreeBSD 7 or later) and the use of <code>__cxa_atexit</code> by default
376(on FreeBSD 6 or later).  The use of <code>dl_iterate_phdr</code> inside
377<samp>libgcc_s.so.1</samp> and boehm-gc (on FreeBSD 7 or later) is enabled
378by GCC 4.5 and above.
379</p>
380<p>We support FreeBSD using the ELF file format with DWARF 2 debugging
381for all CPU architectures.  You may use <samp>-gstabs</samp> instead of
382<samp>-g</samp>, if you really want the old debugging format.  There are
383no known issues with mixing object files and libraries with different
384debugging formats.  Otherwise, this release of GCC should now match
385more of the configuration used in the stock FreeBSD configuration of
386GCC.  In particular, <samp>--enable-threads</samp> is now configured by
387default.  However, as a general user, do not attempt to replace the
388system compiler with this release.  Known to bootstrap and check with
389good results on FreeBSD 7.2-STABLE.  In the past, known to bootstrap
390and check with good results on FreeBSD 3.0, 3.4, 4.0, 4.2, 4.3, 4.4,
3914.5, 4.8, 4.9 and 5-CURRENT.
392</p>
393<p>The version of binutils installed in <samp>/usr/bin</samp> probably works
394with this release of GCC.  Bootstrapping against the latest GNU
395binutils and/or the version found in <samp>/usr/ports/devel/binutils</samp> has
396been known to enable additional features and improve overall testsuite
397results.  However, it is currently known that boehm-gc may not configure
398properly on FreeBSD prior to the FreeBSD 7.0 release with GNU binutils
399after 2.16.1.
400</p>
401<hr />
402<a name="ft32-x-elf"></a><a name="ft32-*-elf"></a>
403<h3 class="heading">ft32-*-elf</h3>
404<p>The FT32 processor.
405This configuration is intended for embedded systems.
406</p>
407<hr />
408<a name="h8300-hms"></a><a name="h8300-hms-1"></a>
409<h3 class="heading">h8300-hms</h3>
410<p>Renesas H8/300 series of processors.
411</p>
412<p>Please have a look at the <a href="binaries.html">binaries page</a>.
413</p>
414<p>The calling convention and structure layout has changed in release 2.6.
415All code must be recompiled.  The calling convention now passes the
416first three arguments in function calls in registers.  Structures are no
417longer a multiple of 2 bytes.
418</p>
419<hr />
420<a name="hppa-hp-hpux"></a><a name="hppa*-hp-hpux*"></a>
421<h3 class="heading">hppa*-hp-hpux*</h3>
422<p>Support for HP-UX version 9 and older was discontinued in GCC 3.4.
423</p>
424<p>We require using gas/binutils on all hppa platforms.  Version 2.19 or
425later is recommended.
426</p>
427<p>It may be helpful to configure GCC with the
428<a href="./configure.html#with-gnu-as"><samp>--with-gnu-as</samp></a> and
429<samp>--with-as=&hellip;</samp> options to ensure that GCC can find GAS.
430</p>
431<p>The HP assembler should not be used with GCC.  It is rarely tested and may
432not work.  It shouldn&rsquo;t be used with any languages other than C due to its
433many limitations.
434</p>
435<p>Specifically, <samp>-g</samp> does not work (HP-UX uses a peculiar debugging
436format which GCC does not know about).  It also inserts timestamps
437into each object file it creates, causing the 3-stage comparison test to
438fail during a bootstrap.  You should be able to continue by saying
439&lsquo;<samp>make all-host all-target</samp>&rsquo; after getting the failure from &lsquo;<samp>make</samp>&rsquo;.
440</p>
441<p>Various GCC features are not supported.  For example, it does not support weak
442symbols or alias definitions.  As a result, explicit template instantiations
443are required when using C++.  This makes it difficult if not impossible to
444build many C++ applications.
445</p>
446<p>There are two default scheduling models for instructions.  These are
447PROCESSOR_7100LC and PROCESSOR_8000.  They are selected from the pa-risc
448architecture specified for the target machine when configuring.
449PROCESSOR_8000 is the default.  PROCESSOR_7100LC is selected when
450the target is a &lsquo;<samp>hppa1*</samp>&rsquo; machine.
451</p>
452<p>The PROCESSOR_8000 model is not well suited to older processors.  Thus,
453it is important to completely specify the machine architecture when
454configuring if you want a model other than PROCESSOR_8000.  The macro
455TARGET_SCHED_DEFAULT can be defined in BOOT_CFLAGS if a different
456default scheduling model is desired.
457</p>
458<p>As of GCC 4.0, GCC uses the UNIX 95 namespace for HP-UX 10.10
459through 11.00, and the UNIX 98 namespace for HP-UX 11.11 and later.
460This namespace change might cause problems when bootstrapping with
461an earlier version of GCC or the HP compiler as essentially the same
462namespace is required for an entire build.  This problem can be avoided
463in a number of ways.  With HP cc, <code>UNIX_STD</code> can be set to &lsquo;<samp>95</samp>&rsquo;
464or &lsquo;<samp>98</samp>&rsquo;.  Another way is to add an appropriate set of predefines
465to <code>CC</code>.  The description for the <samp>munix=</samp> option contains
466a list of the predefines used with each standard.
467</p>
468<p>More specific information to &lsquo;<samp>hppa*-hp-hpux*</samp>&rsquo; targets follows.
469</p>
470<hr />
471<a name="hppa-hp-hpux10"></a><a name="hppa*-hp-hpux10"></a>
472<h3 class="heading">hppa*-hp-hpux10</h3>
473<p>For hpux10.20, we <em>highly</em> recommend you pick up the latest sed patch
474<code>PHCO_19798</code> from HP.
475</p>
476<p>The C++ ABI has changed incompatibly in GCC 4.0.  COMDAT subspaces are
477used for one-only code and data.  This resolves many of the previous
478problems in using C++ on this target.  However, the ABI is not compatible
479with the one implemented under HP-UX 11 using secondary definitions.
480</p>
481<hr />
482<a name="hppa-hp-hpux11"></a><a name="hppa*-hp-hpux11"></a>
483<h3 class="heading">hppa*-hp-hpux11</h3>
484<p>GCC 3.0 and up support HP-UX 11.  GCC 2.95.x is not supported and cannot
485be used to compile GCC 3.0 and up.
486</p>
487<p>The libffi library haven&rsquo;t been ported to 64-bit HP-UX&nbsp;and doesn&rsquo;t build.
488</p>
489<p>Refer to <a href="binaries.html">binaries</a> for information about obtaining
490precompiled GCC binaries for HP-UX.  Precompiled binaries must be obtained
491to build the Ada language as it cannot be bootstrapped using C.  Ada is
492only available for the 32-bit PA-RISC runtime.
493</p>
494<p>Starting with GCC 3.4 an ISO C compiler is required to bootstrap.  The
495bundled compiler supports only traditional C; you will need either HP&rsquo;s
496unbundled compiler, or a binary distribution of GCC.
497</p>
498<p>It is possible to build GCC 3.3 starting with the bundled HP compiler,
499but the process requires several steps.  GCC 3.3 can then be used to
500build later versions.
501</p>
502<p>There are several possible approaches to building the distribution.
503Binutils can be built first using the HP tools.  Then, the GCC
504distribution can be built.  The second approach is to build GCC
505first using the HP tools, then build binutils, then rebuild GCC.
506There have been problems with various binary distributions, so it
507is best not to start from a binary distribution.
508</p>
509<p>On 64-bit capable systems, there are two distinct targets.  Different
510installation prefixes must be used if both are to be installed on
511the same system.  The &lsquo;<samp>hppa[1-2]*-hp-hpux11*</samp>&rsquo; target generates code
512for the 32-bit PA-RISC runtime architecture and uses the HP linker.
513The &lsquo;<samp>hppa64-hp-hpux11*</samp>&rsquo; target generates 64-bit code for the
514PA-RISC 2.0 architecture.
515</p>
516<p>The script config.guess now selects the target type based on the compiler
517detected during configuration.  You must define <code>PATH</code> or <code>CC</code> so
518that configure finds an appropriate compiler for the initial bootstrap.
519When <code>CC</code> is used, the definition should contain the options that are
520needed whenever <code>CC</code> is used.
521</p>
522<p>Specifically, options that determine the runtime architecture must be
523in <code>CC</code> to correctly select the target for the build.  It is also
524convenient to place many other compiler options in <code>CC</code>.  For example,
525<code>CC=&quot;cc -Ac +DA2.0W -Wp,-H16376 -D_CLASSIC_TYPES -D_HPUX_SOURCE&quot;</code>
526can be used to bootstrap the GCC 3.3 branch with the HP compiler in
52764-bit K&amp;R/bundled mode.  The <samp>+DA2.0W</samp> option will result in
528the automatic selection of the &lsquo;<samp>hppa64-hp-hpux11*</samp>&rsquo; target.  The
529macro definition table of cpp needs to be increased for a successful
530build with the HP compiler.  _CLASSIC_TYPES and _HPUX_SOURCE need to
531be defined when building with the bundled compiler, or when using the
532<samp>-Ac</samp> option.  These defines aren&rsquo;t necessary with <samp>-Ae</samp>.
533</p>
534<p>It is best to explicitly configure the &lsquo;<samp>hppa64-hp-hpux11*</samp>&rsquo; target
535with the <samp>--with-ld=&hellip;</samp> option.  This overrides the standard
536search for ld.  The two linkers supported on this target require different
537commands.  The default linker is determined during configuration.  As a
538result, it&rsquo;s not possible to switch linkers in the middle of a GCC build.
539This has been reported to sometimes occur in unified builds of binutils
540and GCC.
541</p>
542<p>A recent linker patch must be installed for the correct operation of
543GCC 3.3 and later.  <code>PHSS_26559</code> and <code>PHSS_24304</code> are the
544oldest linker patches that are known to work.  They are for HP-UX
54511.00 and 11.11, respectively.  <code>PHSS_24303</code>, the companion to
546<code>PHSS_24304</code>, might be usable but it hasn&rsquo;t been tested.  These
547patches have been superseded.  Consult the HP patch database to obtain
548the currently recommended linker patch for your system.
549</p>
550<p>The patches are necessary for the support of weak symbols on the
55132-bit port, and for the running of initializers and finalizers.  Weak
552symbols are implemented using SOM secondary definition symbols.  Prior
553to HP-UX 11, there are bugs in the linker support for secondary symbols.
554The patches correct a problem of linker core dumps creating shared
555libraries containing secondary symbols, as well as various other
556linking issues involving secondary symbols.
557</p>
558<p>GCC 3.3 uses the ELF DT_INIT_ARRAY and DT_FINI_ARRAY capabilities to
559run initializers and finalizers on the 64-bit port.  The 32-bit port
560uses the linker <samp>+init</samp> and <samp>+fini</samp> options for the same
561purpose.  The patches correct various problems with the +init/+fini
562options, including program core dumps.  Binutils 2.14 corrects a
563problem on the 64-bit port resulting from HP&rsquo;s non-standard use of
564the .init and .fini sections for array initializers and finalizers.
565</p>
566<p>Although the HP and GNU linkers are both supported for the
567&lsquo;<samp>hppa64-hp-hpux11*</samp>&rsquo; target, it is strongly recommended that the
568HP linker be used for link editing on this target.
569</p>
570<p>At this time, the GNU linker does not support the creation of long
571branch stubs.  As a result, it cannot successfully link binaries
572containing branch offsets larger than 8 megabytes.  In addition,
573there are problems linking shared libraries, linking executables
574with <samp>-static</samp>, and with dwarf2 unwind and exception support.
575It also doesn&rsquo;t provide stubs for internal calls to global functions
576in shared libraries, so these calls cannot be overloaded.
577</p>
578<p>The HP dynamic loader does not support GNU symbol versioning, so symbol
579versioning is not supported.  It may be necessary to disable symbol
580versioning with <samp>--disable-symvers</samp> when using GNU ld.
581</p>
582<p>POSIX threads are the default.  The optional DCE thread library is not
583supported, so <samp>--enable-threads=dce</samp> does not work.
584</p>
585<hr />
586<a name="x-x-linux-gnu"></a><a name="g_t*-*-linux-gnu"></a>
587<h3 class="heading">*-*-linux-gnu</h3>
588<p>Versions of libstdc++-v3 starting with 3.2.1 require bug fixes present
589in glibc 2.2.5 and later.  More information is available in the
590libstdc++-v3 documentation.
591</p>
592<hr />
593<a name="ix86-x-linux"></a><a name="i_003f86-*-linux*"></a>
594<h3 class="heading">i?86-*-linux*</h3>
595<p>As of GCC 3.3, binutils 2.13.1 or later is required for this platform.
596See <a href="http://gcc.gnu.org/PR10877">bug 10877</a> for more information.
597</p>
598<p>If you receive Signal 11 errors when building on GNU/Linux, then it is
599possible you have a hardware problem.  Further information on this can be
600found on <a href="http://www.bitwizard.nl/sig11/">www.bitwizard.nl</a>.
601</p>
602<hr />
603<a name="ix86-x-solaris2"></a><a name="i_003f86-*-solaris2*"></a>
604<h3 class="heading">i?86-*-solaris2*</h3>
605<p>Use this for Solaris 11.3 or later on x86 and x86-64 systems.  Starting
606with GCC 4.7, there is also a 64-bit &lsquo;<samp>amd64-*-solaris2*</samp>&rsquo; or
607&lsquo;<samp>x86_64-*-solaris2*</samp>&rsquo; configuration that corresponds to
608&lsquo;<samp>sparcv9-sun-solaris2*</samp>&rsquo;.
609</p>
610<p>It is recommended that you configure GCC to use the GNU assembler.  The
611versions included in Solaris 11.3, from GNU binutils 2.23.1 or
612newer (available as <samp>/usr/bin/gas</samp> and
613<samp>/usr/gnu/bin/as</samp>), work fine.  The current version, from GNU
614binutils 2.34, is known to work.  Recent versions of the Solaris assembler in
615<samp>/usr/bin/as</samp> work almost as well, though.
616</p>
617<p>For linking, the Solaris linker is preferred.  If you want to use the GNU
618linker instead, the version in Solaris 11.3, from GNU binutils 2.23.1 or
619newer (in <samp>/usr/gnu/bin/ld</samp> and <samp>/usr/bin/gld</samp>), works,
620as does the latest version, from GNU binutils 2.34.
621</p>
622<p>To use GNU <code>as</code>, configure with the options
623<samp>--with-gnu-as --with-as=/usr/gnu/bin/as</samp>.  It may be necessary
624to configure with <samp>--without-gnu-ld --with-ld=/usr/ccs/bin/ld</samp> to
625guarantee use of Solaris <code>ld</code>.
626</p>
627<hr />
628<a name="ia64-x-linux"></a><a name="ia64-*-linux"></a>
629<h3 class="heading">ia64-*-linux</h3>
630<p>IA-64 processor (also known as IPF, or Itanium Processor Family)
631running GNU/Linux.
632</p>
633<p>If you are using the installed system libunwind library with
634<samp>--with-system-libunwind</samp>, then you must use libunwind 0.98 or
635later.
636</p>
637<p>None of the following versions of GCC has an ABI that is compatible
638with any of the other versions in this list, with the exception that
639Red Hat 2.96 and Trillian 000171 are compatible with each other:
6403.1, 3.0.2, 3.0.1, 3.0, Red Hat 2.96, and Trillian 000717.
641This primarily affects C++ programs and programs that create shared libraries.
642GCC 3.1 or later is recommended for compiling linux, the kernel.
643As of version 3.1 GCC is believed to be fully ABI compliant, and hence no
644more major ABI changes are expected.
645</p>
646<hr />
647<a name="ia64-x-hpux"></a><a name="ia64-*-hpux*"></a>
648<h3 class="heading">ia64-*-hpux*</h3>
649<p>Building GCC on this target requires the GNU Assembler.  The bundled HP
650assembler will not work.  To prevent GCC from using the wrong assembler,
651the option <samp>--with-gnu-as</samp> may be necessary.
652</p>
653<p>The GCC libunwind library has not been ported to HPUX.  This means that for
654GCC versions 3.2.3 and earlier, <samp>--enable-libunwind-exceptions</samp>
655is required to build GCC.  For GCC 3.3 and later, this is the default.
656For gcc 3.4.3 and later, <samp>--enable-libunwind-exceptions</samp> is
657removed and the system libunwind library will always be used.
658</p>
659<hr />
660<!-- rs6000-ibm-aix*, powerpc-ibm-aix* -->
661<a name="x-ibm-aix"></a><a name="g_t*-ibm-aix*"></a>
662<h3 class="heading">*-ibm-aix*</h3>
663<p>Support for AIX version 3 and older was discontinued in GCC 3.4.
664Support for AIX version 4.2 and older was discontinued in GCC 4.5.
665</p>
666<p>&ldquo;out of memory&rdquo; bootstrap failures may indicate a problem with
667process resource limits (ulimit).  Hard limits are configured in the
668<samp>/etc/security/limits</samp> system configuration file.
669</p>
670<p>GCC 4.9 and above require a C++ compiler for bootstrap.  IBM VAC++ / xlC
671cannot bootstrap GCC.  xlc can bootstrap an older version of GCC and
672G++ can bootstrap recent releases of GCC.
673</p>
674<p>GCC can bootstrap with recent versions of IBM XLC, but bootstrapping
675with an earlier release of GCC is recommended.  Bootstrapping with XLC
676requires a larger data segment, which can be enabled through the
677<var>LDR_CNTRL</var> environment variable, e.g.,
678</p>
679<div class="smallexample">
680<pre class="smallexample">% LDR_CNTRL=MAXDATA=0x50000000
681% export LDR_CNTRL
682</pre></div>
683
684<p>One can start with a pre-compiled version of GCC to build from
685sources.  One may delete GCC&rsquo;s &ldquo;fixed&rdquo; header files when starting
686with a version of GCC built for an earlier release of AIX.
687</p>
688<p>To speed up the configuration phases of bootstrapping and installing GCC,
689one may use GNU Bash instead of AIX <code>/bin/sh</code>, e.g.,
690</p>
691<div class="smallexample">
692<pre class="smallexample">% CONFIG_SHELL=/opt/freeware/bin/bash
693% export CONFIG_SHELL
694</pre></div>
695
696<p>and then proceed as described in <a href="build.html">the build
697instructions</a>, where we strongly recommend specifying an absolute path
698to invoke <var>srcdir</var>/configure.
699</p>
700<p>Because GCC on AIX is built as a 32-bit executable by default,
701(although it can generate 64-bit programs) the GMP and MPFR libraries
702required by gfortran must be 32-bit libraries.  Building GMP and MPFR
703as static archive libraries works better than shared libraries.
704</p>
705<p>Errors involving <code>alloca</code> when building GCC generally are due
706to an incorrect definition of <code>CC</code> in the Makefile or mixing files
707compiled with the native C compiler and GCC.  During the stage1 phase of
708the build, the native AIX compiler <strong>must</strong> be invoked as <code>cc</code>
709(not <code>xlc</code>).  Once <code>configure</code> has been informed of
710<code>xlc</code>, one needs to use &lsquo;<samp>make distclean</samp>&rsquo; to remove the
711configure cache files and ensure that <code>CC</code> environment variable
712does not provide a definition that will confuse <code>configure</code>.
713If this error occurs during stage2 or later, then the problem most likely
714is the version of Make (see above).
715</p>
716<p>The native <code>as</code> and <code>ld</code> are recommended for
717bootstrapping on AIX.  The GNU Assembler, GNU Linker, and GNU
718Binutils version 2.20 is the minimum level that supports bootstrap on
719AIX 5.  The GNU Assembler has not been updated to support AIX 6&nbsp;or
720AIX 7.  The native AIX tools do interoperate with GCC.
721</p>
722<p>AIX 7.1 added partial support for DWARF debugging, but full support
723requires AIX 7.1 TL03 SP7 that supports additional DWARF sections and
724fixes a bug in the assembler.  AIX 7.1 TL03 SP5 distributed a version
725of libm.a missing important symbols; a fix for IV77796 will be
726included in SP6.
727</p>
728<p>AIX 5.3 TL10, AIX 6.1 TL05 and AIX 7.1 TL00 introduced an AIX
729assembler change that sometimes produces corrupt assembly files
730causing AIX linker errors.  The bug breaks GCC bootstrap on AIX and
731can cause compilation failures with existing GCC installations.  An
732AIX iFix for AIX 5.3 is available (APAR IZ98385 for AIX 5.3 TL10, APAR
733IZ98477 for AIX 5.3 TL11 and IZ98134 for AIX 5.3 TL12). AIX 5.3 TL11 SP8,
734AIX 5.3 TL12 SP5, AIX 6.1 TL04 SP11, AIX 6.1 TL05 SP7, AIX 6.1 TL06 SP6,
735AIX 6.1 TL07 and AIX 7.1 TL01 should include the fix.
736</p>
737<p>Building <samp>libstdc++.a</samp> requires a fix for an AIX Assembler bug
738APAR IY26685 (AIX 4.3) or APAR IY25528 (AIX 5.1).  It also requires a
739fix for another AIX Assembler bug and a co-dependent AIX Archiver fix
740referenced as APAR IY53606 (AIX 5.2) or as APAR IY54774 (AIX 5.1)
741</p>
742<a name="TransferAixShobj"></a><p>&lsquo;<samp>libstdc++</samp>&rsquo; in GCC 3.4 increments the major version number of the
743shared object and GCC installation places the <samp>libstdc++.a</samp>
744shared library in a common location which will overwrite the and GCC
7453.3 version of the shared library.  Applications either need to be
746re-linked against the new shared library or the GCC 3.1 and GCC 3.3
747versions of the &lsquo;<samp>libstdc++</samp>&rsquo; shared object needs to be available
748to the AIX runtime loader.  The GCC 3.1 &lsquo;<samp>libstdc++.so.4</samp>&rsquo;, if
749present, and GCC 3.3 &lsquo;<samp>libstdc++.so.5</samp>&rsquo; shared objects can be
750installed for runtime dynamic loading using the following steps to set
751the &lsquo;<samp>F_LOADONLY</samp>&rsquo; flag in the shared object for <em>each</em>
752multilib <samp>libstdc++.a</samp> installed:
753</p>
754<p>Extract the shared objects from the currently installed
755<samp>libstdc++.a</samp> archive:
756</p><div class="smallexample">
757<pre class="smallexample">% ar -x libstdc++.a libstdc++.so.4 libstdc++.so.5
758</pre></div>
759
760<p>Enable the &lsquo;<samp>F_LOADONLY</samp>&rsquo; flag so that the shared object will be
761available for runtime dynamic loading, but not linking:
762</p><div class="smallexample">
763<pre class="smallexample">% strip -e libstdc++.so.4 libstdc++.so.5
764</pre></div>
765
766<p>Archive the runtime-only shared object in the GCC 3.4
767<samp>libstdc++.a</samp> archive:
768</p><div class="smallexample">
769<pre class="smallexample">% ar -q libstdc++.a libstdc++.so.4 libstdc++.so.5
770</pre></div>
771
772<p>Eventually, the
773<a href="./configure.html#WithAixSoname"><samp>--with-aix-soname=svr4</samp></a>
774configure option may drop the need for this procedure for libraries that
775support it.
776</p>
777<p>Linking executables and shared libraries may produce warnings of
778duplicate symbols.  The assembly files generated by GCC for AIX always
779have included multiple symbol definitions for certain global variable
780and function declarations in the original program.  The warnings should
781not prevent the linker from producing a correct library or runnable
782executable.
783</p>
784<p>AIX 4.3 utilizes a &ldquo;large format&rdquo; archive to support both 32-bit and
78564-bit object modules.  The routines provided in AIX 4.3.0 and AIX 4.3.1
786to parse archive libraries did not handle the new format correctly.
787These routines are used by GCC and result in error messages during
788linking such as &ldquo;not a COFF file&rdquo;.  The version of the routines shipped
789with AIX 4.3.1 should work for a 32-bit environment.  The <samp>-g</samp>
790option of the archive command may be used to create archives of 32-bit
791objects using the original &ldquo;small format&rdquo;.  A correct version of the
792routines is shipped with AIX 4.3.2 and above.
793</p>
794<p>Some versions of the AIX binder (linker) can fail with a relocation
795overflow severe error when the <samp>-bbigtoc</samp> option is used to link
796GCC-produced object files into an executable that overflows the TOC.  A fix
797for APAR IX75823 (OVERFLOW DURING LINK WHEN USING GCC AND -BBIGTOC) is
798available from IBM Customer Support and from its
799<a href="http://techsupport.services.ibm.com/">techsupport.services.ibm.com</a>
800website as PTF U455193.
801</p>
802<p>The AIX 4.3.2.1 linker (bos.rte.bind_cmds Level 4.3.2.1) will dump core
803with a segmentation fault when invoked by any version of GCC.  A fix for
804APAR IX87327 is available from IBM Customer Support and from its
805<a href="http://techsupport.services.ibm.com/">techsupport.services.ibm.com</a>
806website as PTF U461879.  This fix is incorporated in AIX 4.3.3 and above.
807</p>
808<p>The initial assembler shipped with AIX 4.3.0 generates incorrect object
809files.  A fix for APAR IX74254 (64BIT DISASSEMBLED OUTPUT FROM COMPILER FAILS
810TO ASSEMBLE/BIND) is available from IBM Customer Support and from its
811<a href="http://techsupport.services.ibm.com/">techsupport.services.ibm.com</a>
812website as PTF U453956.  This fix is incorporated in AIX 4.3.1 and above.
813</p>
814<p>AIX provides National Language Support (NLS).  Compilers and assemblers
815use NLS to support locale-specific representations of various data
816formats including floating-point numbers (e.g., &lsquo;<samp>.</samp>&rsquo;  vs &lsquo;<samp>,</samp>&rsquo; for
817separating decimal fractions).  There have been problems reported where
818GCC does not produce the same floating-point formats that the assembler
819expects.  If one encounters this problem, set the <code>LANG</code>
820environment variable to &lsquo;<samp>C</samp>&rsquo; or &lsquo;<samp>En_US</samp>&rsquo;.
821</p>
822<p>A default can be specified with the <samp>-mcpu=<var>cpu_type</var></samp>
823switch and using the configure option <samp>--with-cpu-<var>cpu_type</var></samp>.
824</p>
825<hr />
826<a name="iq2000-x-elf"></a><a name="iq2000-*-elf"></a>
827<h3 class="heading">iq2000-*-elf</h3>
828<p>Vitesse IQ2000 processors.  These are used in embedded
829applications.  There are no standard Unix configurations.
830</p>
831<hr />
832<a name="lm32-x-elf"></a><a name="lm32-*-elf"></a>
833<h3 class="heading">lm32-*-elf</h3>
834<p>Lattice Mico32 processor.
835This configuration is intended for embedded systems.
836</p>
837<hr />
838<a name="lm32-x-uclinux"></a><a name="lm32-*-uclinux"></a>
839<h3 class="heading">lm32-*-uclinux</h3>
840<p>Lattice Mico32 processor.
841This configuration is intended for embedded systems running uClinux.
842</p>
843<hr />
844<a name="m32c-x-elf"></a><a name="m32c-*-elf"></a>
845<h3 class="heading">m32c-*-elf</h3>
846<p>Renesas M32C processor.
847This configuration is intended for embedded systems.
848</p>
849<hr />
850<a name="m32r-x-elf"></a><a name="m32r-*-elf"></a>
851<h3 class="heading">m32r-*-elf</h3>
852<p>Renesas M32R processor.
853This configuration is intended for embedded systems.
854</p>
855<hr />
856<a name="m68k-x-x"></a><a name="m68k-*-*"></a>
857<h3 class="heading">m68k-*-*</h3>
858<p>By default,
859&lsquo;<samp>m68k-*-elf*</samp>&rsquo;, &lsquo;<samp>m68k-*-rtems</samp>&rsquo;,  &lsquo;<samp>m68k-*-uclinux</samp>&rsquo; and
860&lsquo;<samp>m68k-*-linux</samp>&rsquo;
861build libraries for both M680x0 and ColdFire processors.  If you only
862need the M680x0 libraries, you can omit the ColdFire ones by passing
863<samp>--with-arch=m68k</samp> to <code>configure</code>.  Alternatively, you
864can omit the M680x0 libraries by passing <samp>--with-arch=cf</samp> to
865<code>configure</code>.  These targets default to 5206 or 5475 code as
866appropriate for the target system when
867configured with <samp>--with-arch=cf</samp> and 68020 code otherwise.
868</p>
869<p>The &lsquo;<samp>m68k-*-netbsd</samp>&rsquo; and
870&lsquo;<samp>m68k-*-openbsd</samp>&rsquo; targets also support the <samp>--with-arch</samp>
871option.  They will generate ColdFire CFV4e code when configured with
872<samp>--with-arch=cf</samp> and 68020 code otherwise.
873</p>
874<p>You can override the default processors listed above by configuring
875with <samp>--with-cpu=<var>target</var></samp>.  This <var>target</var> can either
876be a <samp>-mcpu</samp> argument or one of the following values:
877&lsquo;<samp>m68000</samp>&rsquo;, &lsquo;<samp>m68010</samp>&rsquo;, &lsquo;<samp>m68020</samp>&rsquo;, &lsquo;<samp>m68030</samp>&rsquo;,
878&lsquo;<samp>m68040</samp>&rsquo;, &lsquo;<samp>m68060</samp>&rsquo;, &lsquo;<samp>m68020-40</samp>&rsquo; and &lsquo;<samp>m68020-60</samp>&rsquo;.
879</p>
880<p>GCC requires at least binutils version 2.17 on these targets.
881</p>
882<hr />
883<a name="m68k-x-uclinux"></a><a name="m68k-*-uclinux"></a>
884<h3 class="heading">m68k-*-uclinux</h3>
885<p>GCC 4.3 changed the uClinux configuration so that it uses the
886&lsquo;<samp>m68k-linux-gnu</samp>&rsquo; ABI rather than the &lsquo;<samp>m68k-elf</samp>&rsquo; ABI.
887It also added improved support for C++ and flat shared libraries,
888both of which were ABI changes.
889</p>
890<hr />
891<a name="microblaze-x-elf"></a><a name="microblaze-*-elf"></a>
892<h3 class="heading">microblaze-*-elf</h3>
893<p>Xilinx MicroBlaze processor.
894This configuration is intended for embedded systems.
895</p>
896<hr />
897<a name="mips-x-x"></a><a name="mips-*-*"></a>
898<h3 class="heading">mips-*-*</h3>
899<p>If on a MIPS system you get an error message saying &ldquo;does not have gp
900sections for all it&rsquo;s [sic] sectons [sic]&rdquo;, don&rsquo;t worry about it.  This
901happens whenever you use GAS with the MIPS linker, but there is not
902really anything wrong, and it is okay to use the output file.  You can
903stop such warnings by installing the GNU linker.
904</p>
905<p>It would be nice to extend GAS to produce the gp tables, but they are
906optional, and there should not be a warning about their absence.
907</p>
908<p>The libstdc++ atomic locking routines for MIPS targets requires MIPS II
909and later.  A patch went in just after the GCC 3.3 release to
910make &lsquo;<samp>mips*-*-*</samp>&rsquo; use the generic implementation instead.  You can also
911configure for &lsquo;<samp>mipsel-elf</samp>&rsquo; as a workaround.  The
912&lsquo;<samp>mips*-*-linux*</samp>&rsquo; target continues to use the MIPS II routines.  More
913work on this is expected in future releases.
914</p>
915
916<p>The built-in <code>__sync_*</code> functions are available on MIPS II and
917later systems and others that support the &lsquo;<samp>ll</samp>&rsquo;, &lsquo;<samp>sc</samp>&rsquo; and
918&lsquo;<samp>sync</samp>&rsquo; instructions.  This can be overridden by passing
919<samp>--with-llsc</samp> or <samp>--without-llsc</samp> when configuring GCC.
920Since the Linux kernel emulates these instructions if they are
921missing, the default for &lsquo;<samp>mips*-*-linux*</samp>&rsquo; targets is
922<samp>--with-llsc</samp>.  The <samp>--with-llsc</samp> and
923<samp>--without-llsc</samp> configure options may be overridden at compile
924time by passing the <samp>-mllsc</samp> or <samp>-mno-llsc</samp> options to
925the compiler.
926</p>
927<p>MIPS systems check for division by zero (unless
928<samp>-mno-check-zero-division</samp> is passed to the compiler) by
929generating either a conditional trap or a break instruction.  Using
930trap results in smaller code, but is only supported on MIPS II and
931later.  Also, some versions of the Linux kernel have a bug that
932prevents trap from generating the proper signal (<code>SIGFPE</code>).  To enable
933the use of break, use the <samp>--with-divide=breaks</samp>
934<code>configure</code> option when configuring GCC.  The default is to
935use traps on systems that support them.
936</p>
937<hr />
938<a name="moxie-x-elf"></a><a name="moxie-*-elf"></a>
939<h3 class="heading">moxie-*-elf</h3>
940<p>The moxie processor.
941</p>
942<hr />
943<a name="msp430-x-elf"></a><a name="msp430-*-elf*"></a>
944<h3 class="heading">msp430-*-elf*</h3>
945<p>TI MSP430 processor.
946This configuration is intended for embedded systems.
947</p>
948<p>&lsquo;<samp>msp430-*-elf</samp>&rsquo; is the standard configuration with most GCC
949features enabled by default.
950</p>
951<p>&lsquo;<samp>msp430-*-elfbare</samp>&rsquo; is tuned for a bare-metal environment, and disables
952features related to shared libraries and other functionality not used for
953this device.  This reduces code and data usage of the GCC libraries, resulting
954in a minimal run-time environment by default.
955</p>
956<p>Features disabled by default include:
957</p><ul>
958<li> transactional memory
959</li><li> __cxa_atexit
960</li></ul>
961
962<hr />
963<a name="nds32le-x-elf"></a><a name="nds32le-*-elf"></a>
964<h3 class="heading">nds32le-*-elf</h3>
965<p>Andes NDS32 target in little endian mode.
966</p>
967<hr />
968<a name="nds32be-x-elf"></a><a name="nds32be-*-elf"></a>
969<h3 class="heading">nds32be-*-elf</h3>
970<p>Andes NDS32 target in big endian mode.
971</p>
972<hr />
973<a name="nvptx-x-none"></a><a name="nvptx-*-none"></a>
974<h3 class="heading">nvptx-*-none</h3>
975<p>Nvidia PTX target.
976</p>
977<p>Instead of GNU binutils, you will need to install
978<a href="https://github.com/MentorEmbedded/nvptx-tools/">nvptx-tools</a>.
979Tell GCC where to find it:
980<samp>--with-build-time-tools=[install-nvptx-tools]/nvptx-none/bin</samp>.
981</p>
982<p>You will need newlib 3.0 git revision
983cd31fbb2aea25f94d7ecedc9db16dfc87ab0c316 or later.  It can be
984automatically built together with GCC.  For this, add a symbolic link
985to nvptx-newlib&rsquo;s <samp>newlib</samp> directory to the directory containing
986the GCC sources.
987</p>
988<p>Use the <samp>--disable-sjlj-exceptions</samp> and
989<samp>--enable-newlib-io-long-long</samp> options when configuring.
990</p>
991<hr />
992<a name="or1k-x-elf"></a><a name="or1k-*-elf"></a>
993<h3 class="heading">or1k-*-elf</h3>
994<p>The OpenRISC 1000 32-bit processor with delay slots.
995This configuration is intended for embedded systems.
996</p>
997<hr />
998<a name="or1k-x-linux"></a><a name="or1k-*-linux"></a>
999<h3 class="heading">or1k-*-linux</h3>
1000<p>The OpenRISC 1000 32-bit processor with delay slots.
1001</p>
1002<hr />
1003<a name="powerpc-x-x"></a><a name="powerpc-*-*"></a>
1004<h3 class="heading">powerpc-*-*</h3>
1005<p>You can specify a default version for the <samp>-mcpu=<var>cpu_type</var></samp>
1006switch by using the configure option <samp>--with-cpu-<var>cpu_type</var></samp>.
1007</p>
1008<p>You will need GNU binutils 2.20 or newer.
1009</p>
1010<hr />
1011<a name="powerpc-x-darwin"></a><a name="powerpc-*-darwin*"></a>
1012<h3 class="heading">powerpc-*-darwin*</h3>
1013<p>PowerPC running Darwin (Mac OS X kernel).
1014</p>
1015<p>Pre-installed versions of Mac OS X may not include any developer tools,
1016meaning that you will not be able to build GCC from source.  Tool
1017binaries are available at
1018<a href="https://opensource.apple.com">https://opensource.apple.com</a>.
1019</p>
1020<p>This version of GCC requires at least cctools-590.36.  The
1021cctools-590.36 package referenced from
1022<a href="http://gcc.gnu.org/ml/gcc/2006-03/msg00507.html">http://gcc.gnu.org/ml/gcc/2006-03/msg00507.html</a> will not work
1023on systems older than 10.3.9 (aka darwin7.9.0).
1024</p>
1025<hr />
1026<a name="powerpc-x-elf"></a><a name="powerpc-*-elf"></a>
1027<h3 class="heading">powerpc-*-elf</h3>
1028<p>PowerPC system in big endian mode, running System V.4.
1029</p>
1030<hr />
1031<a name="powerpc-x-linux-gnu"></a><a name="powerpc*-*-linux-gnu*"></a>
1032<h3 class="heading">powerpc*-*-linux-gnu*</h3>
1033<p>PowerPC system in big endian mode running Linux.
1034</p>
1035<hr />
1036<a name="powerpc-x-netbsd"></a><a name="powerpc-*-netbsd*"></a>
1037<h3 class="heading">powerpc-*-netbsd*</h3>
1038<p>PowerPC system in big endian mode running NetBSD.
1039</p>
1040<hr />
1041<a name="powerpc-x-eabisim"></a><a name="powerpc-*-eabisim"></a>
1042<h3 class="heading">powerpc-*-eabisim</h3>
1043<p>Embedded PowerPC system in big endian mode for use in running under the
1044PSIM simulator.
1045</p>
1046<hr />
1047<a name="powerpc-x-eabi"></a><a name="powerpc-*-eabi"></a>
1048<h3 class="heading">powerpc-*-eabi</h3>
1049<p>Embedded PowerPC system in big endian mode.
1050</p>
1051<hr />
1052<a name="powerpcle-x-elf"></a><a name="powerpcle-*-elf"></a>
1053<h3 class="heading">powerpcle-*-elf</h3>
1054<p>PowerPC system in little endian mode, running System V.4.
1055</p>
1056<hr />
1057<a name="powerpcle-x-eabisim"></a><a name="powerpcle-*-eabisim"></a>
1058<h3 class="heading">powerpcle-*-eabisim</h3>
1059<p>Embedded PowerPC system in little endian mode for use in running under
1060the PSIM simulator.
1061</p>
1062<hr />
1063<a name="powerpcle-x-eabi"></a><a name="powerpcle-*-eabi"></a>
1064<h3 class="heading">powerpcle-*-eabi</h3>
1065<p>Embedded PowerPC system in little endian mode.
1066</p>
1067<hr />
1068<a name="rl78-x-elf"></a><a name="rl78-*-elf"></a>
1069<h3 class="heading">rl78-*-elf</h3>
1070<p>The Renesas RL78 processor.
1071This configuration is intended for embedded systems.
1072</p>
1073<hr />
1074<a name="riscv32-x-elf"></a><a name="riscv32-*-elf"></a>
1075<h3 class="heading">riscv32-*-elf</h3>
1076<p>The RISC-V RV32 instruction set.
1077This configuration is intended for embedded systems.
1078This (and all other RISC-V) targets require the binutils 2.30 release.
1079</p>
1080<hr />
1081<a name="riscv32-x-linux"></a><a name="riscv32-*-linux"></a>
1082<h3 class="heading">riscv32-*-linux</h3>
1083<p>The RISC-V RV32 instruction set running GNU/Linux.
1084This (and all other RISC-V) targets require the binutils 2.30 release.
1085</p>
1086<hr />
1087<a name="riscv64-x-elf"></a><a name="riscv64-*-elf"></a>
1088<h3 class="heading">riscv64-*-elf</h3>
1089<p>The RISC-V RV64 instruction set.
1090This configuration is intended for embedded systems.
1091This (and all other RISC-V) targets require the binutils 2.30 release.
1092</p>
1093<hr />
1094<a name="riscv64-x-linux"></a><a name="riscv64-*-linux"></a>
1095<h3 class="heading">riscv64-*-linux</h3>
1096<p>The RISC-V RV64 instruction set running GNU/Linux.
1097This (and all other RISC-V) targets require the binutils 2.30 release.
1098</p>
1099<hr />
1100<a name="rx-x-elf"></a><a name="rx-*-elf"></a>
1101<h3 class="heading">rx-*-elf</h3>
1102<p>The Renesas RX processor.
1103</p>
1104<hr />
1105<a name="s390-x-linux"></a><a name="s390-*-linux*"></a>
1106<h3 class="heading">s390-*-linux*</h3>
1107<p>S/390 system running GNU/Linux for S/390.
1108</p>
1109<hr />
1110<a name="s390x-x-linux"></a><a name="s390x-*-linux*"></a>
1111<h3 class="heading">s390x-*-linux*</h3>
1112<p>zSeries system (64-bit) running GNU/Linux for zSeries.
1113</p>
1114<hr />
1115<a name="s390x-ibm-tpf"></a><a name="s390x-ibm-tpf*"></a>
1116<h3 class="heading">s390x-ibm-tpf*</h3>
1117<p>zSeries system (64-bit) running TPF.  This platform is
1118supported as cross-compilation target only.
1119</p>
1120<hr />
1121<a name="x-x-solaris2"></a><a name="g_t*-*-solaris2*"></a>
1122<h3 class="heading">*-*-solaris2*</h3>
1123<p>Support for Solaris 10 has been removed in GCC 10.  Support for Solaris
11249 has been removed in GCC 5.  Support for Solaris 8 has been removed in
1125GCC 4.8.  Support for Solaris 7 has been removed in GCC 4.6.
1126</p>
1127<p>Solaris 11.3 provides GCC 4.5.2, 4.7.3, and 4.8.2 as
1128<code>/usr/gcc/4.5/bin/gcc</code> or similar.  Newer Solaris versions
1129provide one or more of GCC 5, 7, and 9.  Alternatively,
1130you can install a pre-built GCC to bootstrap and install GCC.  See the
1131<a href="binaries.html">binaries page</a> for details.
1132</p>
1133<p>The Solaris 2 <code>/bin/sh</code> will often fail to configure
1134&lsquo;<samp>libstdc++-v3</samp>&rsquo;.  We therefore recommend using the
1135following initial sequence of commands
1136</p>
1137<div class="smallexample">
1138<pre class="smallexample">% CONFIG_SHELL=/bin/ksh
1139% export CONFIG_SHELL
1140</pre></div>
1141
1142<p>and proceed as described in <a href="configure.html">the configure instructions</a>.
1143In addition we strongly recommend specifying an absolute path to invoke
1144<code><var>srcdir</var>/configure</code>.
1145</p>
1146<p>In Solaris 11, you need to check for <code>system/header</code>,
1147<code>system/linker</code>, and <code>developer/assembler</code> packages.
1148</p>
1149<p>Trying to use the linker and other tools in
1150<samp>/usr/ucb</samp> to install GCC has been observed to cause trouble.
1151For example, the linker may hang indefinitely.  The fix is to remove
1152<samp>/usr/ucb</samp> from your <code>PATH</code>.
1153</p>
1154<p>The build process works more smoothly with the legacy Solaris tools so, if you
1155have <samp>/usr/xpg4/bin</samp> in your <code>PATH</code>, we recommend that you place
1156<samp>/usr/bin</samp> before <samp>/usr/xpg4/bin</samp> for the duration of the build.
1157</p>
1158<p>We recommend the use of the Solaris assembler or the GNU assembler, in
1159conjunction with the Solaris linker.  The GNU <code>as</code>
1160versions included in Solaris 11.3,
1161from GNU binutils 2.23.1 or newer (in <samp>/usr/bin/gas</samp> and
1162<samp>/usr/gnu/bin/as</samp>), are known to work.
1163The current version, from GNU binutils 2.34,
1164is known to work as well.  Note that your mileage may vary
1165if you use a combination of the GNU tools and the Solaris tools: while the
1166combination GNU <code>as</code> + Solaris <code>ld</code> should reasonably work,
1167the reverse combination Solaris <code>as</code> + GNU <code>ld</code> may fail to
1168build or cause memory corruption at runtime in some cases for C++ programs.
1169GNU <code>ld</code> usually works as well.  Again, the current
1170version (2.34) is known to work, but generally lacks platform specific
1171features, so better stay with Solaris <code>ld</code>.  To use the LTO linker
1172plugin (<samp>-fuse-linker-plugin</samp>) with GNU <code>ld</code>, GNU
1173binutils <em>must</em> be configured with <samp>--enable-largefile</samp>.
1174</p>
1175<p>To enable symbol versioning in &lsquo;<samp>libstdc++</samp>&rsquo; with the Solaris linker,
1176you need to have any version of GNU <code>c++filt</code>, which is part of
1177GNU binutils.  &lsquo;<samp>libstdc++</samp>&rsquo; symbol versioning will be disabled if no
1178appropriate version is found.  Solaris <code>c++filt</code> from the Solaris
1179Studio compilers does <em>not</em> work.
1180</p>
1181<p>The versions of the GNU Multiple Precision Library (GMP), the MPFR
1182library and the MPC library bundled with Solaris 11.3 and later are
1183usually recent enough to match GCC&rsquo;s requirements.  There are two
1184caveats:
1185</p>
1186<ul>
1187<li> While the version of the GMP library in Solaris 11.3 works with GCC, you
1188need to configure with <samp>--with-gmp-include=/usr/include/gmp</samp>.
1189
1190</li><li> The version of the MPFR libary included in Solaris 11.3 is too old; you
1191need to provide a more recent one.
1192</li></ul>
1193
1194<hr />
1195<a name="sparc-x-x"></a><a name="sparc*-*-*"></a>
1196<h3 class="heading">sparc*-*-*</h3>
1197<p>This section contains general configuration information for all
1198SPARC-based platforms.  In addition to reading this section, please
1199read all other sections that match your target.
1200</p>
1201<p>Newer versions of the GNU Multiple Precision Library (GMP), the MPFR
1202library and the MPC library are known to be miscompiled by earlier
1203versions of GCC on these platforms.  We therefore recommend the use
1204of the exact versions of these libraries listed as minimal versions
1205in <a href="prerequisites.html">the prerequisites</a>.
1206</p>
1207<hr />
1208<a name="sparc-sun-solaris2"></a><a name="sparc-sun-solaris2*"></a>
1209<h3 class="heading">sparc-sun-solaris2*</h3>
1210<p>When GCC is configured to use GNU binutils 2.14 or later, the binaries
1211produced are smaller than the ones produced using Solaris native tools;
1212this difference is quite significant for binaries containing debugging
1213information.
1214</p>
1215<p>Starting with Solaris 7, the operating system is capable of executing
121664-bit SPARC V9 binaries.  GCC 3.1 and later properly supports
1217this; the <samp>-m64</samp> option enables 64-bit code generation.
1218However, if all you want is code tuned for the UltraSPARC CPU, you
1219should try the <samp>-mtune=ultrasparc</samp> option instead, which produces
1220code that, unlike full 64-bit code, can still run on non-UltraSPARC
1221machines.
1222</p>
1223<p>When configuring the GNU Multiple Precision Library (GMP), the MPFR
1224library or the MPC library on a Solaris 7 or later system, the canonical
1225target triplet must be specified as the <code>build</code> parameter on the
1226configure line.  This target triplet can be obtained by invoking <code>./config.guess</code> in the toplevel source directory of GCC (and
1227not that of GMP or MPFR or MPC).  For example on a Solaris 11 system:
1228</p>
1229<div class="smallexample">
1230<pre class="smallexample">% ./configure --build=sparc-sun-solaris2.11 --prefix=xxx
1231</pre></div>
1232
1233<hr />
1234<a name="sparc-x-linux"></a><a name="sparc-*-linux*"></a>
1235<h3 class="heading">sparc-*-linux*</h3>
1236
1237<hr />
1238<a name="sparc64-x-solaris2"></a><a name="sparc64-*-solaris2*"></a>
1239<h3 class="heading">sparc64-*-solaris2*</h3>
1240<p>When configuring a 64-bit-default GCC on Solaris/SPARC, you must use a
1241build compiler that generates 64-bit code, either by default or by
1242specifying &lsquo;<samp>CC='gcc -m64' CXX='gcc-m64'</samp>&rsquo; to <code>configure</code>.
1243Additionally, you <em>must</em> pass <samp>--build=sparc64-sun-solaris2.11</samp>
1244or <samp>--build=sparcv9-sun-solaris2.11</samp> because <samp>config.guess</samp>
1245misdetects this situation, which can cause build failures.
1246</p>
1247<p>When configuring the GNU Multiple Precision Library (GMP), the MPFR
1248library or the MPC library, the canonical target triplet must be specified
1249as the <code>build</code> parameter on the configure line.  For example
1250on a Solaris 11 system:
1251</p>
1252<div class="smallexample">
1253<pre class="smallexample">% ./configure --build=sparc64-sun-solaris2.11 --prefix=xxx
1254</pre></div>
1255
1256<hr />
1257<a name="sparcv9-x-solaris2"></a><a name="sparcv9-*-solaris2*"></a>
1258<h3 class="heading">sparcv9-*-solaris2*</h3>
1259<p>This is a synonym for &lsquo;<samp>sparc64-*-solaris2*</samp>&rsquo;.
1260</p>
1261<hr />
1262<a name="c6x-x-x"></a><a name="c6x-*-*"></a>
1263<h3 class="heading">c6x-*-*</h3>
1264<p>The C6X family of processors. This port requires binutils-2.22 or newer.
1265</p>
1266<hr />
1267<a name="tilegx-*-linux"></a><a name="tilegx-*-linux*"></a>
1268<h3 class="heading">tilegx-*-linux*</h3>
1269<p>The TILE-Gx processor in little endian mode, running GNU/Linux.  This
1270port requires binutils-2.22 or newer.
1271</p>
1272<hr />
1273<a name="tilegxbe-*-linux"></a><a name="tilegxbe-*-linux*"></a>
1274<h3 class="heading">tilegxbe-*-linux*</h3>
1275<p>The TILE-Gx processor in big endian mode, running GNU/Linux.  This
1276port requires binutils-2.23 or newer.
1277</p>
1278<hr />
1279<a name="tilepro-*-linux"></a><a name="tilepro-*-linux*"></a>
1280<h3 class="heading">tilepro-*-linux*</h3>
1281<p>The TILEPro processor running GNU/Linux.  This port requires
1282binutils-2.22 or newer.
1283</p>
1284<hr />
1285<a name="visium-x-elf"></a><a name="visium-*-elf"></a>
1286<h3 class="heading">visium-*-elf</h3>
1287<p>CDS VISIUMcore processor.
1288This configuration is intended for embedded systems.
1289</p>
1290<hr />
1291<a name="x-x-vxworks"></a><a name="g_t*-*-vxworks*"></a>
1292<h3 class="heading">*-*-vxworks*</h3>
1293<p>Support for VxWorks is in flux.  At present GCC supports <em>only</em> the
1294very recent VxWorks 5.5 (aka Tornado 2.2) release, and only on PowerPC.
1295We welcome patches for other architectures supported by VxWorks 5.5.
1296Support for VxWorks AE would also be welcome; we believe this is merely
1297a matter of writing an appropriate &ldquo;configlette&rdquo; (see below).  We are
1298not interested in supporting older, a.out or COFF-based, versions of
1299VxWorks in GCC 3.
1300</p>
1301<p>VxWorks comes with an older version of GCC installed in
1302<samp><var>$WIND_BASE</var>/host</samp>; we recommend you do not overwrite it.
1303Choose an installation <var>prefix</var> entirely outside <var>$WIND_BASE</var>.
1304Before running <code>configure</code>, create the directories <samp><var>prefix</var></samp>
1305and <samp><var>prefix</var>/bin</samp>.  Link or copy the appropriate assembler,
1306linker, etc. into <samp><var>prefix</var>/bin</samp>, and set your <var>PATH</var> to
1307include that directory while running both <code>configure</code> and
1308<code>make</code>.
1309</p>
1310<p>You must give <code>configure</code> the
1311<samp>--with-headers=<var>$WIND_BASE</var>/target/h</samp> switch so that it can
1312find the VxWorks system headers.  Since VxWorks is a cross compilation
1313target only, you must also specify <samp>--target=<var>target</var></samp>.
1314<code>configure</code> will attempt to create the directory
1315<samp><var>prefix</var>/<var>target</var>/sys-include</samp> and copy files into it;
1316make sure the user running <code>configure</code> has sufficient privilege
1317to do so.
1318</p>
1319<p>GCC&rsquo;s exception handling runtime requires a special &ldquo;configlette&rdquo;
1320module, <samp>contrib/gthr_supp_vxw_5x.c</samp>.  Follow the instructions in
1321that file to add the module to your kernel build.  (Future versions of
1322VxWorks will incorporate this module.)
1323</p>
1324<hr />
1325<a name="x86-64-x-x"></a><a name="x86_005f64-*-*_002c-amd64-*-*"></a>
1326<h3 class="heading">x86_64-*-*, amd64-*-*</h3>
1327<p>GCC supports the x86-64 architecture implemented by the AMD64 processor
1328(amd64-*-* is an alias for x86_64-*-*) on GNU/Linux, FreeBSD and NetBSD.
1329On GNU/Linux the default is a bi-arch compiler which is able to generate
1330both 64-bit x86-64 and 32-bit x86 code (via the <samp>-m32</samp> switch).
1331</p>
1332<hr />
1333<a name="x86-64-x-solaris2"></a><a name="x86_005f64-*-solaris2*"></a>
1334<h3 class="heading">x86_64-*-solaris2*</h3>
1335<p>GCC also supports the x86-64 architecture implemented by the AMD64
1336processor (&lsquo;<samp>amd64-*-*</samp>&rsquo; is an alias for &lsquo;<samp>x86_64-*-*</samp>&rsquo;) on
1337Solaris 10 or later.  Unlike other systems, without special options a
1338bi-arch compiler is built which generates 32-bit code by default, but
1339can generate 64-bit x86-64 code with the <samp>-m64</samp> switch.  Since
1340GCC 4.7, there is also a configuration that defaults to 64-bit code, but
1341can generate 32-bit code with <samp>-m32</samp>.  To configure and build
1342this way, you have to provide all support libraries like <samp>libgmp</samp>
1343as 64-bit code, configure with <samp>--target=x86_64-pc-solaris2.11</samp>
1344and &lsquo;<samp>CC=gcc -m64</samp>&rsquo;.
1345</p>
1346<hr />
1347<a name="xtensa-x-elf"></a><a name="xtensa*-*-elf"></a>
1348<h3 class="heading">xtensa*-*-elf</h3>
1349<p>This target is intended for embedded Xtensa systems using the
1350&lsquo;<samp>newlib</samp>&rsquo; C library.  It uses ELF but does not support shared
1351objects.  Designed-defined instructions specified via the
1352Tensilica Instruction Extension (TIE) language are only supported
1353through inline assembly.
1354</p>
1355<p>The Xtensa configuration information must be specified prior to
1356building GCC.  The <samp>include/xtensa-config.h</samp> header
1357file contains the configuration information.  If you created your
1358own Xtensa configuration with the Xtensa Processor Generator, the
1359downloaded files include a customized copy of this header file,
1360which you can use to replace the default header file.
1361</p>
1362<hr />
1363<a name="xtensa-x-linux"></a><a name="xtensa*-*-linux*"></a>
1364<h3 class="heading">xtensa*-*-linux*</h3>
1365<p>This target is for Xtensa systems running GNU/Linux.  It supports ELF
1366shared objects and the GNU C library (glibc).  It also generates
1367position-independent code (PIC) regardless of whether the
1368<samp>-fpic</samp> or <samp>-fPIC</samp> options are used.  In other
1369respects, this target is the same as the
1370<a href="#xtensa*-*-elf">&lsquo;<samp>xtensa*-*-elf</samp>&rsquo;</a> target.
1371</p>
1372<hr />
1373<a name="windows"></a><a name="Microsoft-Windows"></a>
1374<h3 class="heading">Microsoft Windows</h3>
1375
1376<a name="Intel-16-bit-versions"></a>
1377<h4 class="subheading">Intel 16-bit versions</h4>
1378<p>The 16-bit versions of Microsoft Windows, such as Windows 3.1, are not
1379supported.
1380</p>
1381<p>However, the 32-bit port has limited support for Microsoft
1382Windows 3.11 in the Win32s environment, as a target only.  See below.
1383</p>
1384<a name="Intel-32-bit-versions"></a>
1385<h4 class="subheading">Intel 32-bit versions</h4>
1386<p>The 32-bit versions of Windows, including Windows 95, Windows NT, Windows
1387XP, and Windows Vista, are supported by several different target
1388platforms.  These targets differ in which Windows subsystem they target
1389and which C libraries are used.
1390</p>
1391<ul>
1392<li> Cygwin <a href="#x-x-cygwin">*-*-cygwin</a>: Cygwin provides a user-space
1393Linux API emulation layer in the Win32 subsystem.
1394</li><li> MinGW <a href="#x-x-mingw32">*-*-mingw32</a>: MinGW is a native GCC port for
1395the Win32 subsystem that provides a subset of POSIX.
1396</li><li> MKS i386-pc-mks: NuTCracker from MKS.  See
1397<a href="https://www.mkssoftware.com">https://www.mkssoftware.com</a> for more information.
1398</li></ul>
1399
1400<a name="Intel-64-bit-versions"></a>
1401<h4 class="subheading">Intel 64-bit versions</h4>
1402<p>GCC contains support for x86-64 using the mingw-w64
1403runtime library, available from <a href="http://mingw-w64.org/doku.php">http://mingw-w64.org/doku.php</a>.
1404This library should be used with the target triple x86_64-pc-mingw32.
1405</p>
1406<p>Presently Windows for Itanium is not supported.
1407</p>
1408<a name="Windows-CE"></a>
1409<h4 class="subheading">Windows CE</h4>
1410<p>Windows CE is supported as a target only on Hitachi
1411SuperH (sh-wince-pe), and MIPS (mips-wince-pe).
1412</p>
1413<a name="Other-Windows-Platforms"></a>
1414<h4 class="subheading">Other Windows Platforms</h4>
1415<p>GCC no longer supports Windows NT on the Alpha or PowerPC.
1416</p>
1417<p>GCC no longer supports the Windows POSIX subsystem.  However, it does
1418support the Interix subsystem.  See above.
1419</p>
1420<p>Old target names including *-*-winnt and *-*-windowsnt are no longer used.
1421</p>
1422<p>PW32 (i386-pc-pw32) support was never completed, and the project seems to
1423be inactive.  See <a href="http://pw32.sourceforge.net/">http://pw32.sourceforge.net/</a> for more information.
1424</p>
1425<p>UWIN support has been removed due to a lack of maintenance.
1426</p>
1427<hr />
1428<a name="x-x-cygwin"></a><a name="g_t*-*-cygwin"></a>
1429<h3 class="heading">*-*-cygwin</h3>
1430<p>Ports of GCC are included with the
1431<a href="http://www.cygwin.com/">Cygwin environment</a>.
1432</p>
1433<p>GCC will build under Cygwin without modification; it does not build
1434with Microsoft&rsquo;s C++ compiler and there are no plans to make it do so.
1435</p>
1436<p>The Cygwin native compiler can be configured to target any 32-bit x86
1437cpu architecture desired; the default is i686-pc-cygwin.  It should be
1438used with as up-to-date a version of binutils as possible; use either
1439the latest official GNU binutils release in the Cygwin distribution,
1440or version 2.20 or above if building your own.
1441</p>
1442<hr />
1443<a name="x-x-mingw32"></a><a name="g_t*-*-mingw32"></a>
1444<h3 class="heading">*-*-mingw32</h3>
1445<p>GCC will build with and support only MinGW runtime 3.12 and later.
1446Earlier versions of headers are incompatible with the new default semantics
1447of <code>extern inline</code> in <code>-std=c99</code> and <code>-std=gnu99</code> modes.
1448</p>
1449<hr />
1450<a name="older"></a><a name="Older-systems"></a>
1451<h3 class="heading">Older systems</h3>
1452<p>GCC contains support files for many older (1980s and early
14531990s) Unix variants.  For the most part, support for these systems
1454has not been deliberately removed, but it has not been maintained for
1455several years and may suffer from bitrot.
1456</p>
1457<p>Starting with GCC 3.1, each release has a list of &ldquo;obsoleted&rdquo; systems.
1458Support for these systems is still present in that release, but
1459<code>configure</code> will fail unless the <samp>--enable-obsolete</samp>
1460option is given.  Unless a maintainer steps forward, support for these
1461systems will be removed from the next release of GCC.
1462</p>
1463<p>Support for old systems as hosts for GCC can cause problems if the
1464workarounds for compiler, library and operating system bugs affect the
1465cleanliness or maintainability of the rest of GCC.  In some cases, to
1466bring GCC up on such a system, if still possible with current GCC, may
1467require first installing an old version of GCC which did work on that
1468system, and using it to compile a more recent GCC, to avoid bugs in the
1469vendor compiler.  Old releases of GCC 1 and GCC 2 are available in the
1470<samp>old-releases</samp> directory on the <a href="../mirrors.html">GCC mirror
1471sites</a>.  Header bugs may generally be avoided using
1472<code>fixincludes</code>, but bugs or deficiencies in libraries and the
1473operating system may still cause problems.
1474</p>
1475<p>Support for older systems as targets for cross-compilation is less
1476problematic than support for them as hosts for GCC; if an enthusiast
1477wishes to make such a target work again (including resurrecting any of
1478the targets that never worked with GCC 2, starting from the last
1479version before they were removed), patches
1480<a href="../contribute.html">following the usual requirements</a> would be
1481likely to be accepted, since they should not affect the support for more
1482modern targets.
1483</p>
1484<p>For some systems, old versions of GNU binutils may also be useful,
1485and are available from <samp>pub/binutils/old-releases</samp> on
1486<a href="https://sourceware.org/mirrors.html">sourceware.org mirror sites</a>.
1487</p>
1488<p>Some of the information on specific systems above relates to
1489such older systems, but much of the information
1490about GCC on such systems (which may no longer be applicable to
1491current GCC) is to be found in the GCC texinfo manual.
1492</p>
1493<hr />
1494<a name="elf"></a><a name="all-ELF-targets-_0028SVR4_002c-Solaris-2_002c-etc_002e_0029"></a>
1495<h3 class="heading">all ELF targets (SVR4, Solaris 2, etc.)</h3>
1496<p>C++ support is significantly better on ELF targets if you use the
1497<a href="./configure.html#with-gnu-ld">GNU linker</a>; duplicate copies of
1498inlines, vtables and template instantiations will be discarded
1499automatically.
1500</p>
1501
1502<hr />
1503<p>
1504<p><a href="./index.html">Return to the GCC Installation page</a>
1505</p>
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