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gerrit-public.fairphone.software / toolchain / llvm-project / ab77bc588dd67479109e91aa7b4859ec60fac1b5 / . / llvm / docs / ReleaseNotes.html
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Chris Lattner7c4bd1d2003-10-27 01:31:14 +0000[diff] [blame]2<html><head><title>LLVM 1.1 Release Notes</title></head>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]3<body bgcolor=white>
4
5<table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
Chris Lattner7c4bd1d2003-10-27 01:31:14 +0000[diff] [blame]6<tr><td>&nbsp; <font size=+3 color="#EEEEFF" face="Georgia,Palatino,Times,Roman"><b>LLVM 1.1 Release Notes</b></font></td>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]7</tr></table>
8
9<ol>
Chris Lattnera9b4c392003-10-02 05:09:46 +0000[diff] [blame]10 <li><a href="#intro">Introduction</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]11 <li><a href="#whatsnew">What's New?</a>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]12 <li><a href="#portability">Portability and Supported Platforms</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]13 <li><a href="#install-instructions">Installation Instructions</a>
14 <li><a href="#knownproblems">Known Problems</a>
15 <ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]16<!-- <li><a href="#portabilityprobs">Portability Problems</a> -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#core">Known problems with the LLVM Core</a>
18 <li><a href="#c-fe">Known problems with the C Front-end</a>
19 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
20 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
21 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
22 <li><a href="#c-be">Known problems with the C back-end</a>
23 </ul>
24 <li><a href="#additionalinfo">Additional Information</a>
25 </ul>
26
27 <p><b>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></b><p>
28</ol>
29
30
31<!-- *********************************************************************** -->
32<table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
33<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
34<a name="intro">Introduction
35</b></font></td></tr></table><ul>
36<!-- *********************************************************************** -->
37
38This document contains the release notes for the LLVM compiler infrastructure,
Chris Lattner7c4bd1d2003-10-27 01:31:14 +0000[diff] [blame]39release 1.1. Here we describe the status of LLVM, including any known problems,
40and bug fixes from the previous release. The most up-to-date version of this
41document can be found on the <a
42href="http://llvm.cs.uiuc.edu/releases/1.1/">LLVM 1.1 web site</a>. If you are
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]43not reading this on the LLVM web pages, you should probably go there, because
44this document may be updated after the release.<p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]45
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]46For more information about LLVM, including information about potentially more
47current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
48web site</a>. If you have questions or comments, the <a
49href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
50list</a> is a good place to send them.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]51
Chris Lattner7c4bd1d2003-10-27 01:31:14 +0000[diff] [blame]52Note that if you are reading this file from CVS, that this document applies to
53the <i>next</i> release, not the previous one. To see the release notes for the
54previous release, see the <a href="http://llvm.cs.uiuc.edu/releases/">releases
55page</a>.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]56
57<!-- *********************************************************************** -->
58</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
59<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
60<a name="whatsnew">What's New?
61</b></font></td></tr></table><ul>
62<!-- *********************************************************************** -->
63
Chris Lattner7c4bd1d2003-10-27 01:31:14 +0000[diff] [blame]64This is the second public release of the LLVM compiler infrastructure. This
65release implements the following new features:<p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]66
67<ol>
Chris Lattneref114d52003-11-03 20:08:08 +0000[diff] [blame]68<li><a href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new LLVM profiler, similar to gprof</a> is available</li>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]69</ol><p>
70
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]71In this release, the following Quality of Implementation issues were fixed:<p>
72
73<ol>
74<li><a href="http://llvm.cs.uiuc.edu/PR29">C++ front-end is not generating linkonce linkage type when it can</a></li>
75</ol><p>
76
Chris Lattner25fd5c12003-10-27 05:41:39 +0000[diff] [blame]77In this release, the following bugs in the previous release were fixed:<p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]78
79<ol>
Chris Lattner25fd5c12003-10-27 05:41:39 +0000[diff] [blame]80<li><a href="http://llvm.cs.uiuc.edu/PR57">[inliner] Inlining invoke with PHI in unwind target is broken</a></li>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]81<li><a href="http://llvm.cs.uiuc.edu/PR58">[linker] linkonce globals should link successfully to external globals</a></li>
Chris Lattnerd16d9752003-10-27 17:58:57 +0000[diff] [blame]82<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
Chris Lattner36213c72003-10-28 23:13:03 +0000[diff] [blame]83<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
Chris Lattner56df0a52003-10-29 01:26:07 +0000[diff] [blame]84<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
Chris Lattnera1a090e2003-10-29 07:17:13 +0000[diff] [blame]85<li><a href="http://llvm.cs.uiuc.edu/PR64">[constmerge] Constant merging pass merges constants with external linkage</a></li>
86<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
Chris Lattner5b83b562003-10-29 18:49:14 +0000[diff] [blame]87<li><a href="http://llvm.cs.uiuc.edu/PR66">[scalarrepl] Scalar Replacement of aggregates is decimating structures it shouldn't be</a></li>
88<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
Chris Lattnerab8873d2003-10-29 20:59:45 +0000[diff] [blame]89<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
90<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
Chris Lattnera2bd4e02003-10-30 01:20:42 +0000[diff] [blame]91<li><a href="http://llvm.cs.uiuc.edu/PR70">[instcombine] Resolving invoke inserts cast after terminator</a></li>
Chris Lattnera306dd22003-10-30 01:43:33 +0000[diff] [blame]92<li><a href="http://llvm.cs.uiuc.edu/PR71">llvm-as crashes when labels are used in phi nodes</a></li>
Chris Lattnerb45e1f92003-10-30 16:20:15 +0000[diff] [blame]93<li><a href="http://llvm.cs.uiuc.edu/PR72">[build problem] Callgraph.cpp not pulled in from libipa.a</a></li>
Chris Lattnerdd024a02003-11-02 02:15:11 +0000[diff] [blame]94<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
95<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
96<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
Chris Lattneref114d52003-11-03 20:08:08 +0000[diff] [blame]97<li><a href="http://llvm.cs.uiuc.edu/PR83">[X86] Emission of global bool initializers broken</a></li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]98<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
Chris Lattnerab77bc52003-11-05 06:30:04 +0000[diff] [blame^]99<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
100<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
101<li><a href="http://llvm.cs.uiuc.edu/PR91">[gccld] The -r (relinking) option does not work correctly</a></li>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]102</ol><p>
103
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]104At this time, LLVM is known to work properly with SPEC CPU 2000, the Olden
105benchmarks, and the Ptrdist benchmarks among many other programs. Note however
106that the Sparc and X86 backends do not currently support exception throwing or
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]107long jumping (including 253.perlbmk in SPEC). For these programs you must use
108the C backend.<p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]109
110
111<!-- *********************************************************************** -->
112</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
113<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
114<a name="portability">Portability and Supported Platforms
115</b></font></td></tr></table><ul>
116<!-- *********************************************************************** -->
117
Brian Gaeke7b51ed52003-10-22 18:19:08 +0000[diff] [blame]118LLVM has only been extensively tested on Intel and AMD machines running Red
119Hat Linux, and Sun UltraSPARC workstations running Solaris 8.
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]120The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
121work on more platforms than that. However, it is extremely likely that we
122missed something. We welcome portability patches and error messages.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]123
124
125<!-- *********************************************************************** -->
126</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
127<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]128<a name="knownproblems">Known Problems
129</b></font></td></tr></table><ul>
130<!-- *********************************************************************** -->
131
132This section contains all known problems with the LLVM system, listed by
133component. As new problems are discovered, they will be added to these
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]134sections.
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]135
136
137<!-- _______________________________________________________________________ -->
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]138<!--
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]139</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]140-->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]141
142
143<!-- _______________________________________________________________________ -->
144</ul><h4><a name="core"><hr size=0>Known problems with the LLVM Core</h4><ul>
145
146<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not work.<p>
147
148<li>The JIT does not use mutexes to protect its internal data structures. As
149 such, execution of a threaded program could cause these data structures to
150 be corrupted.<p>
151
152<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.<p>
153
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]154<li>Linking in static archive files (.a files) is very slow (there is no symbol
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]155table in the archive).<p>
156
157<li><a href="http://llvm.cs.uiuc.edu/PR88">Interpreter does not support invoke
158or unwind</a>.<p>
159
160<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
161more than 256 elements</a>.<p>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]162
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]163<!-- _______________________________________________________________________ -->
164</ul><h4><a name="c-fe"><hr size=0>Known problems with the C front-end</h4><ul>
165
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]166</ul><b>Bugs:</b><ul><p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]167
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR6">Oversized integer bitfields cause crash</a>.<p>
169
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]170<li>C99 Variable sized arrays do not release stack memory when they go out of
171 scope. Thus, the following program may run out of stack space:
172<pre>
173 for (i = 0; i != 1000000; ++i) {
174 int X[n];
175 foo(X);
176 }
177</pre><p>
178
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]179</ul><b>Notes:</b><ul><p>
180
181<li>Inline assembly is not yet supported.<p>
182
183<li>"long double" is transformed by the front-end into "double". There is no
184 support for floating point data types of any size other than 32 and 64 bits.
185 <p>
186
Chris Lattnera9b4c392003-10-02 05:09:46 +0000[diff] [blame]187<li>The following Unix system functionality has not been tested and may not work:
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]188<ol>
189 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
John Criswell9d977d52003-10-27 17:41:53 +0000[diff] [blame]190 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
191 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]192 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
193 - These functions have not been tested.
194</ol><p>
195
196<li>Although many GCC extensions are supported, some are not. In particular,
197 the following extensions are known to <b>not be</b> supported:
198 <ol>
199 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.
200 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels, and computed gotos.
201 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>: As in Algol and Pascal, lexical scoping of functions.
202 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.
203 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.
204 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands
205 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html#Asm%20Labels">Asm Labels</a>: Specifying the assembler name to use for a C symbol.
206 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.
207 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.
208 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.
209 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.
210 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.
211 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.
212 </ol><p>
213
214 The following GCC extensions are <b>partially</b> supported. An ignored
215 attribute means that the LLVM compiler ignores the presence of the attribute,
216 but the code should still work. An unsupported attribute is one which is
217 ignored by the LLVM compiler, which will cause a different interpretation of
218 the program.<p>
219
220 <ol>
221 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
222 Arrays whose length is computed at run time.<br>
223 Supported, but allocated stack space is not freed until the function returns (noted above).
224
225 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
226 Declaring that functions have no side effects, or that they can never return.<br>
227 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>, <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>, <tt>deprecated</tt>,
228 <tt>warn_unused_result</tt>, <tt>weak</tt><br>
229 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>, <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>, <tt>malloc</tt>
230 <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
231 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>, <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
232 <tt>fastcall</tt>, all other target specific attributes
233
234 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
235 Specifying attributes of variables.<br>
236 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
237 <tt>deprecated</tt>, <tt>transparent_union</tt>,
238 <tt>unused</tt>, <tt>weak</tt><br>
239 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
240 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
241 <tt>vector_size</tt>, <tt>dllimport</tt>,
242 <tt>dllexport</tt>, all target specific attributes.<br>
243
244 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.
245 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
246 <tt>deprecated</tt>, <tt>may_alias</tt>
247 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>
248 all target specific attributes.<br>
249 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
250 Other built-in functions.<br>
251 We support all builtins which have a C language equivalent (e.g.,
252 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
253 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
254 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).
255 </ol><p>
256
257
258 The following extensions <b>are</b> known to be supported:
259 <ol>
260 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.
261 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]262 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]263 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.
264 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.
265 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.
266 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.
267 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.
268 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.
269 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.
270 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.
271 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.
272 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>:Arithmetic on <code>void</code>-pointers and function pointers.
273 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.
274 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions or arrays as values.
275 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.
276
277 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>:Casting to union type from any member of the union.
278 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.
279 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.
280
281 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.
282 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.
283 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.
284 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Character-Escapes.html#Character%20Escapes">Character Escapes</a>: <code>\e</code> stands for the character &lt;ESC&gt;.
285 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.
286 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).
287 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate%20Keywords">Alternate Keywords</a>:<code>__const__</code>, <code>__asm__</code>, etc., for header files.
288 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Incomplete-Enums.html#Incomplete%20Enums">Incomplete Enums</a>: <code>enum foo;</code>, with details to follow.
289 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.
290 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.
291 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.
292 </ol><p>
293
294 If you run into GCC extensions which have not been included in any of these
295 lists, please let us know (also including whether or not they work).
296
297
298<!-- _______________________________________________________________________ -->
299</ul><h4><a name="c++-fe"><hr size=0>Known problems with the C++ front-end</h4><ul>
300
John Criswell9d977d52003-10-27 17:41:53 +0000[diff] [blame]301For this release, the C++ front-end is considered to be fully functional but
302of <b>beta</b> quality. It has been tested and works for a number of simple programs that collectively exercise most of the language. Nevertheless, it has not been in use as long as the C front-end. Please report any bugs or problems.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]303
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]304</ul><b>Bugs</b>:<ul><p>
305
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]306<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
307 front-end</a><p>
308
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]309</ul><b>Notes</b>:<ul><p>
310
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]311<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
312parser is significantly more standards compliant (and picky) than prior GCC
313versions. For more information, see the C++ section of the <a
314href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.<p>
315
316<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]317 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]318 function and in the <tt>setjmp</tt> receiver function may not be run.
319 Objects in intervening stack frames will be destroyed however (which is
320 better than most compilers).<p>
321
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]322<li>The LLVM C++ front-end follows the <a
323 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
324 This document, which is not Itanium specific, specifies a standard for name
325 mangling, class layout, v-table layout, RTTI formats, and other C++
326 representation issues. Because we use this API, code generated by the LLVM
327 compilers should be binary compatible with machine code generated by other
328 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
329 <i>However</i>, the exception handling mechanism used by LLVM is very
330 different from the model used in the Itanium ABI, so <b>exceptions will not
331 interact correctly</b> .
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]332
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]333<li><a href="http://llvm.cs.uiuc.edu/PR11">Code for executing destructors when
334 unwinding is not shared</a> (this is a quality of implementation problem,
335 which does not effect functionality).<p>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]336
337
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]338<!-- _______________________________________________________________________ -->
339</ul><h4><a name="x86-be"><hr size=0>Known problems with the X86 back-end</h4><ul>
340
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]341<li>The X86 code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]342href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]343support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
344or calls the C <tt>longjmp</tt> function will abort.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]345
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]346
347<!-- _______________________________________________________________________ -->
348</ul><h4><a name="sparc-be"><hr size=0>Known problems with the Sparc back-end</h4><ul>
349
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]350<li>The Sparc code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]351href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]352support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
353or calls the C <tt>longjmp</tt> function will abort.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]354
355
356<!-- _______________________________________________________________________ -->
357</ul><h4><a name="c-be"><hr size=0>Known problems with the C back-end</h4><ul>
358
359<li>The C back-end produces code that violates the ANSI C Type-Based Alias
360Analysis rules. As such, special options may be necessary to compile the code
361(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
362problem probably cannot be fixed.<p>
363
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]364<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
365cannot include special floating point numbers like Not-A-Number or Infinity.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]366
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]367<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]368supported</a>. This should not affect LLVM produced by the C or C++
369frontends.<p>
370
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]371<li><a href="http://llvm.cs.uiuc.edu/PR77">Variables in scope of output setjmp
372calls should be volatile</a>. Note that this does not effect correctness on
373many platforms.<p>
374
375<li>The code produces by the C back-end has only been tested with the Sun CC,
376GCC, and Intel compilers. It is possible that it will have to be adjusted to
377support other C compilers.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]378
379
380
381<!-- *********************************************************************** -->
382</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
383<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
384<a name="additionalinfo">Additional Information
385</b></font></td></tr></table><ul>
386<!-- *********************************************************************** -->
387
388A wide variety of additional information is available on the LLVM web page,
389including mailing lists publications describing algorithms and components
390implemented in LLVM. The web page also contains versions of the API
391documentation which is up-to-date with the CVS version of the source code. You
392can access versions of these documents specific to this release by going into
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]393the "<tt>llvm/doc/</tt>" directory in the LLVM tree.<p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]394
395If you have any questions or comments about LLVM, please feel free to contact us
396via the mailing lists.<p>
397
398
399<!-- *********************************************************************** -->
400</ul>
401<!-- *********************************************************************** -->
402
403<hr><font size-1>
404
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]405Maintained By: <a href="http://llvm.cs.uiuc.edu/">The LLVM Team</a><br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]406<!-- Created: Wed Oct 1 17:38:54 CDT 2003 -->
407<!-- hhmts start -->
Chris Lattnerab77bc52003-11-05 06:30:04 +0000[diff] [blame^]408Last modified: Wed Nov 5 00:07:20 CST 2003
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]409<!-- hhmts end -->
410</body></html>