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Chris Lattner12d90632003-10-27 01:31:14 +0000[diff] [blame]2<html><head><title>LLVM 1.1 Release Notes</title></head>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]3<body bgcolor=white>
4
5<table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
Chris Lattner12d90632003-10-27 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]7</tr></table>
8
9<ol>
Chris Lattner824b9a62003-10-02 05:09:46 +0000[diff] [blame]10 <li><a href="#intro">Introduction</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11 <li><a href="#whatsnew">What's New?</a>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]12 <li><a href="#portability">Portability and Supported Platforms</a>
Chris Lattner79c3fe12003-10-02 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 Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]16<!-- <li><a href="#portabilityprobs">Portability Problems</a> -->
Chris Lattner79c3fe12003-10-02 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 Lattner12d90632003-10-27 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 Lattner47ad72c2003-10-07 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 Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]45
Chris Lattner47ad72c2003-10-07 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]51
Chris Lattner12d90632003-10-27 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 Lattner79c3fe12003-10-02 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 Lattner12d90632003-10-27 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 Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]66
67<ol>
Chris Lattner12d90632003-10-27 01:31:14 +0000[diff] [blame]68<li>temp</li>
69<li>temp</li>
70<li>temp</li>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]71</ol><p>
72
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]73In this release, the following Quality of Implementation issues were fixed:<p>
74
75<ol>
76<li><a href="http://llvm.cs.uiuc.edu/PR29">C++ front-end is not generating linkonce linkage type when it can</a></li>
77</ol><p>
78
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]79In this release, the following bugs in the previous release were fixed:<p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]80
81<ol>
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]82<li><a href="http://llvm.cs.uiuc.edu/PR57">[inliner] Inlining invoke with PHI in unwind target is broken</a></li>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]83<li><a href="http://llvm.cs.uiuc.edu/PR58">[linker] linkonce globals should link successfully to external globals</a></li>
Chris Lattner4ad4b3a2003-10-27 17:58:57 +0000[diff] [blame]84<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
Chris Lattner2c17a892003-10-28 23:13:03 +0000[diff] [blame]85<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
Chris Lattner287b6212003-10-29 01:26:07 +0000[diff] [blame]86<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
Chris Lattner32547fe2003-10-29 07:17:13 +0000[diff] [blame]87<li><a href="http://llvm.cs.uiuc.edu/PR64">[constmerge] Constant merging pass merges constants with external linkage</a></li>
88<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
Chris Lattner34790e52003-10-29 18:49:14 +0000[diff] [blame]89<li><a href="http://llvm.cs.uiuc.edu/PR66">[scalarrepl] Scalar Replacement of aggregates is decimating structures it shouldn't be</a></li>
90<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
Chris Lattner05b958d2003-10-29 20:59:45 +0000[diff] [blame]91<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
92<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
Chris Lattner36bd5d12003-10-30 01:20:42 +0000[diff] [blame]93<li><a href="http://llvm.cs.uiuc.edu/PR70">[instcombine] Resolving invoke inserts cast after terminator</a></li>
Chris Lattnerf9e8a0f2003-10-30 01:43:33 +0000[diff] [blame^]94<li><a href="http://llvm.cs.uiuc.edu/PR71">llvm-as crashes when labels are used in phi nodes</a></li>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]95</ol><p>
96
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]97At this time, LLVM is known to work properly with SPEC CPU 2000, the Olden
98benchmarks, and the Ptrdist benchmarks among many other programs. Note however
99that the Sparc and X86 backends do not currently support exception throwing or
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]100long jumping (including 253.perlbmk in SPEC). For these programs you must use
101the C backend.<p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]102
103
104<!-- *********************************************************************** -->
105</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
106<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
107<a name="portability">Portability and Supported Platforms
108</b></font></td></tr></table><ul>
109<!-- *********************************************************************** -->
110
Brian Gaeke15a2a252003-10-22 18:19:08 +0000[diff] [blame]111LLVM has only been extensively tested on Intel and AMD machines running Red
112Hat Linux, and Sun UltraSPARC workstations running Solaris 8.
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]113The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
114work on more platforms than that. However, it is extremely likely that we
115missed something. We welcome portability patches and error messages.<p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]116
117
118<!-- *********************************************************************** -->
119</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
120<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]121<a name="knownproblems">Known Problems
122</b></font></td></tr></table><ul>
123<!-- *********************************************************************** -->
124
125This section contains all known problems with the LLVM system, listed by
126component. As new problems are discovered, they will be added to these
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]127sections.
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]128
129
130<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]131<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]132</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]133-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]134
135
136<!-- _______________________________________________________________________ -->
137</ul><h4><a name="core"><hr size=0>Known problems with the LLVM Core</h4><ul>
138
139<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not work.<p>
140
141<li>The JIT does not use mutexes to protect its internal data structures. As
142 such, execution of a threaded program could cause these data structures to
143 be corrupted.<p>
144
145<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.<p>
146
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]147<li>Linking in static archive files (.a files) is very slow (there is no symbol
148table in the archive).
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]149
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]150<!-- _______________________________________________________________________ -->
151</ul><h4><a name="c-fe"><hr size=0>Known problems with the C front-end</h4><ul>
152
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]153</ul><b>Bugs:</b><ul><p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]154
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]155<li><a href="http://llvm.cs.uiuc.edu/PR6">Oversized integer bitfields cause crash</a>.<p>
156
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]157<li>C99 Variable sized arrays do not release stack memory when they go out of
158 scope. Thus, the following program may run out of stack space:
159<pre>
160 for (i = 0; i != 1000000; ++i) {
161 int X[n];
162 foo(X);
163 }
164</pre><p>
165
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]166</ul><b>Notes:</b><ul><p>
167
168<li>Inline assembly is not yet supported.<p>
169
170<li>"long double" is transformed by the front-end into "double". There is no
171 support for floating point data types of any size other than 32 and 64 bits.
172 <p>
173
Chris Lattner824b9a62003-10-02 05:09:46 +0000[diff] [blame]174<li>The following Unix system functionality has not been tested and may not work:
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]175<ol>
176 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
John Criswell97745952003-10-27 17:41:53 +0000[diff] [blame]177 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
178 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]179 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
180 - These functions have not been tested.
181</ol><p>
182
183<li>Although many GCC extensions are supported, some are not. In particular,
184 the following extensions are known to <b>not be</b> supported:
185 <ol>
186 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.
187 <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.
188 <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.
189 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.
190 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.
191 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands
192 <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.
193 <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.
194 <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.
195 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.
196 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.
197 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.
198 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.
199 </ol><p>
200
201 The following GCC extensions are <b>partially</b> supported. An ignored
202 attribute means that the LLVM compiler ignores the presence of the attribute,
203 but the code should still work. An unsupported attribute is one which is
204 ignored by the LLVM compiler, which will cause a different interpretation of
205 the program.<p>
206
207 <ol>
208 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
209 Arrays whose length is computed at run time.<br>
210 Supported, but allocated stack space is not freed until the function returns (noted above).
211
212 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
213 Declaring that functions have no side effects, or that they can never return.<br>
214 <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>,
215 <tt>warn_unused_result</tt>, <tt>weak</tt><br>
216 <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>
217 <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
218 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>, <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
219 <tt>fastcall</tt>, all other target specific attributes
220
221 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
222 Specifying attributes of variables.<br>
223 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
224 <tt>deprecated</tt>, <tt>transparent_union</tt>,
225 <tt>unused</tt>, <tt>weak</tt><br>
226 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
227 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
228 <tt>vector_size</tt>, <tt>dllimport</tt>,
229 <tt>dllexport</tt>, all target specific attributes.<br>
230
231 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.
232 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
233 <tt>deprecated</tt>, <tt>may_alias</tt>
234 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>
235 all target specific attributes.<br>
236 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
237 Other built-in functions.<br>
238 We support all builtins which have a C language equivalent (e.g.,
239 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
240 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
241 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).
242 </ol><p>
243
244
245 The following extensions <b>are</b> known to be supported:
246 <ol>
247 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.
248 <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 Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]249 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]250 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.
251 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.
252 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.
253 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.
254 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.
255 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.
256 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.
257 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.
258 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.
259 <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.
260 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.
261 <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.
262 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.
263
264 <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.
265 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.
266 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.
267
268 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.
269 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.
270 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.
271 <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;.
272 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.
273 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).
274 <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.
275 <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.
276 <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.
277 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.
278 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.
279 </ol><p>
280
281 If you run into GCC extensions which have not been included in any of these
282 lists, please let us know (also including whether or not they work).
283
284
285<!-- _______________________________________________________________________ -->
286</ul><h4><a name="c++-fe"><hr size=0>Known problems with the C++ front-end</h4><ul>
287
John Criswell97745952003-10-27 17:41:53 +0000[diff] [blame]288For this release, the C++ front-end is considered to be fully functional but
289of <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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]290
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]291</ul><b>Bugs</b>:<ul><p>
292
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]293<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
294 front-end</a><p>
295
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]296</ul><b>Notes</b>:<ul><p>
297
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]298<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
299parser is significantly more standards compliant (and picky) than prior GCC
300versions. For more information, see the C++ section of the <a
301href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.<p>
302
303<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]304 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]305 function and in the <tt>setjmp</tt> receiver function may not be run.
306 Objects in intervening stack frames will be destroyed however (which is
307 better than most compilers).<p>
308
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]309<li>The LLVM C++ front-end follows the <a
310 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
311 This document, which is not Itanium specific, specifies a standard for name
312 mangling, class layout, v-table layout, RTTI formats, and other C++
313 representation issues. Because we use this API, code generated by the LLVM
314 compilers should be binary compatible with machine code generated by other
315 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
316 <i>However</i>, the exception handling mechanism used by LLVM is very
317 different from the model used in the Itanium ABI, so <b>exceptions will not
318 interact correctly</b> .
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]319
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]320<li><a href="http://llvm.cs.uiuc.edu/PR11">Code for executing destructors when
321 unwinding is not shared</a> (this is a quality of implementation problem,
322 which does not effect functionality).<p>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]323
324
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]325<!-- _______________________________________________________________________ -->
326</ul><h4><a name="x86-be"><hr size=0>Known problems with the X86 back-end</h4><ul>
327
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]328<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]329href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]330support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
331or calls the C <tt>longjmp</tt> function will abort.<p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]332
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333
334<!-- _______________________________________________________________________ -->
335</ul><h4><a name="sparc-be"><hr size=0>Known problems with the Sparc back-end</h4><ul>
336
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]337<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]338href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]339support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
340or calls the C <tt>longjmp</tt> function will abort.<p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341
342
343<!-- _______________________________________________________________________ -->
344</ul><h4><a name="c-be"><hr size=0>Known problems with the C back-end</h4><ul>
345
346<li>The C back-end produces code that violates the ANSI C Type-Based Alias
347Analysis rules. As such, special options may be necessary to compile the code
348(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
349problem probably cannot be fixed.<p>
350
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]351<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
352cannot include special floating point numbers like Not-A-Number or Infinity.<p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]353
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]354<li><a href="http://zion.cs.uiuc.edu/PR56">Zero arg vararg functions are not
355supported</a>. This should not affect LLVM produced by the C or C++
356frontends.<p>
357
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]358<li>The code produces by the C back-end has only been tested with the Sun CC and
359GCC compilers. It is possible that it will have to be adjusted to support other
360C compilers.<p>
361
362
363
364<!-- *********************************************************************** -->
365</ul><table width="100%" bgcolor="#330077" border=0 cellpadding=4 cellspacing=0>
366<tr><td align=center><font color="#EEEEFF" size=+2 face="Georgia,Palatino"><b>
367<a name="additionalinfo">Additional Information
368</b></font></td></tr></table><ul>
369<!-- *********************************************************************** -->
370
371A wide variety of additional information is available on the LLVM web page,
372including mailing lists publications describing algorithms and components
373implemented in LLVM. The web page also contains versions of the API
374documentation which is up-to-date with the CVS version of the source code. You
375can access versions of these documents specific to this release by going into
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]376the "<tt>llvm/doc/</tt>" directory in the LLVM tree.<p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]377
378If you have any questions or comments about LLVM, please feel free to contact us
379via the mailing lists.<p>
380
381
382<!-- *********************************************************************** -->
383</ul>
384<!-- *********************************************************************** -->
385
386<hr><font size-1>
387
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]388Maintained By: <a href="http://llvm.cs.uiuc.edu/">The LLVM Team</a><br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]389<!-- Created: Wed Oct 1 17:38:54 CDT 2003 -->
390<!-- hhmts start -->
Chris Lattnerf9e8a0f2003-10-30 01:43:33 +0000[diff] [blame^]391Last modified: Wed Oct 29 19:41:39 CST 2003
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]392<!-- hhmts end -->
393</body></html>