Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" |
| 2 | "http://www.w3.org/TR/html4/strict.dtd"> |
| 3 | <html> |
| 4 | <head> |
NAKAMURA Takumi | 5c6e4df | 2011-10-31 11:21:59 +0000 | [diff] [blame] | 5 | <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 6 | <title>Extending LLVM: Adding instructions, intrinsics, types, etc.</title> |
Daniel Dunbar | adea497 | 2012-04-19 20:20:34 +0000 | [diff] [blame] | 7 | <link rel="stylesheet" href="_static/llvm.css" type="text/css"> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 8 | </head> |
| 9 | |
| 10 | <body> |
| 11 | |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 12 | <h1> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 13 | Extending LLVM: Adding instructions, intrinsics, types, etc. |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 14 | </h1> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 15 | |
| 16 | <ol> |
| 17 | <li><a href="#introduction">Introduction and Warning</a></li> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 18 | <li><a href="#intrinsic">Adding a new intrinsic function</a></li> |
Chris Lattner | 3636540 | 2004-04-09 19:24:20 +0000 | [diff] [blame] | 19 | <li><a href="#instruction">Adding a new instruction</a></li> |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 20 | <li><a href="#sdnode">Adding a new SelectionDAG node</a></li> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 21 | <li><a href="#type">Adding a new type</a> |
| 22 | <ol> |
| 23 | <li><a href="#fund_type">Adding a new fundamental type</a></li> |
| 24 | <li><a href="#derived_type">Adding a new derived type</a></li> |
| 25 | </ol></li> |
| 26 | </ol> |
| 27 | |
Chris Lattner | 7911ce2 | 2004-05-23 21:07:27 +0000 | [diff] [blame] | 28 | <div class="doc_author"> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 29 | <p>Written by <a href="http://misha.brukman.net">Misha Brukman</a>, |
Chris Lattner | b5f6e25 | 2006-01-16 16:31:40 +0000 | [diff] [blame] | 30 | Brad Jones, Nate Begeman, |
| 31 | and <a href="http://nondot.org/sabre">Chris Lattner</a></p> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 32 | </div> |
| 33 | |
| 34 | <!-- *********************************************************************** --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 35 | <h2> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 36 | <a name="introduction">Introduction and Warning</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 37 | </h2> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 38 | <!-- *********************************************************************** --> |
| 39 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 40 | <div> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 41 | |
| 42 | <p>During the course of using LLVM, you may wish to customize it for your |
| 43 | research project or for experimentation. At this point, you may realize that |
| 44 | you need to add something to LLVM, whether it be a new fundamental type, a new |
| 45 | intrinsic function, or a whole new instruction.</p> |
| 46 | |
| 47 | <p>When you come to this realization, stop and think. Do you really need to |
| 48 | extend LLVM? Is it a new fundamental capability that LLVM does not support at |
| 49 | its current incarnation or can it be synthesized from already pre-existing LLVM |
| 50 | elements? If you are not sure, ask on the <a |
| 51 | href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM-dev</a> list. The |
| 52 | reason is that extending LLVM will get involved as you need to update all the |
| 53 | different passes that you intend to use with your extension, and there are |
| 54 | <em>many</em> LLVM analyses and transformations, so it may be quite a bit of |
| 55 | work.</p> |
| 56 | |
Chris Lattner | 35dd5b0 | 2006-04-12 17:42:39 +0000 | [diff] [blame] | 57 | <p>Adding an <a href="#intrinsic">intrinsic function</a> is far easier than |
| 58 | adding an instruction, and is transparent to optimization passes. If your added |
| 59 | functionality can be expressed as a |
Misha Brukman | b3b2827 | 2004-04-06 04:17:51 +0000 | [diff] [blame] | 60 | function call, an intrinsic function is the method of choice for LLVM |
| 61 | extension.</p> |
| 62 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 63 | <p>Before you invest a significant amount of effort into a non-trivial |
| 64 | extension, <span class="doc_warning">ask on the list</span> if what you are |
| 65 | looking to do can be done with already-existing infrastructure, or if maybe |
| 66 | someone else is already working on it. You will save yourself a lot of time and |
| 67 | effort by doing so.</p> |
| 68 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 69 | </div> |
| 70 | |
| 71 | <!-- *********************************************************************** --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 72 | <h2> |
Chris Lattner | 3636540 | 2004-04-09 19:24:20 +0000 | [diff] [blame] | 73 | <a name="intrinsic">Adding a new intrinsic function</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 74 | </h2> |
Chris Lattner | 3636540 | 2004-04-09 19:24:20 +0000 | [diff] [blame] | 75 | <!-- *********************************************************************** --> |
| 76 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 77 | <div> |
Chris Lattner | 3636540 | 2004-04-09 19:24:20 +0000 | [diff] [blame] | 78 | |
| 79 | <p>Adding a new intrinsic function to LLVM is much easier than adding a new |
| 80 | instruction. Almost all extensions to LLVM should start as an intrinsic |
| 81 | function and then be turned into an instruction if warranted.</p> |
| 82 | |
| 83 | <ol> |
| 84 | <li><tt>llvm/docs/LangRef.html</tt>: |
| 85 | Document the intrinsic. Decide whether it is code generator specific and |
| 86 | what the restrictions are. Talk to other people about it so that you are |
| 87 | sure it's a good idea.</li> |
| 88 | |
Chris Lattner | 35dd5b0 | 2006-04-12 17:42:39 +0000 | [diff] [blame] | 89 | <li><tt>llvm/include/llvm/Intrinsics*.td</tt>: |
| 90 | Add an entry for your intrinsic. Describe its memory access characteristics |
Reid Spencer | c8d0636 | 2007-04-01 07:44:52 +0000 | [diff] [blame] | 91 | for optimization (this controls whether it will be DCE'd, CSE'd, etc). Note |
| 92 | that any intrinsic using the <tt>llvm_int_ty</tt> type for an argument will |
| 93 | be deemed by <tt>tblgen</tt> as overloaded and the corresponding suffix |
| 94 | will be required on the intrinsic's name.</li> |
Chris Lattner | 0190fdb | 2004-04-10 06:56:53 +0000 | [diff] [blame] | 95 | |
Nate Begeman | 2f86c22 | 2006-01-14 01:27:10 +0000 | [diff] [blame] | 96 | <li><tt>llvm/lib/Analysis/ConstantFolding.cpp</tt>: If it is possible to |
| 97 | constant fold your intrinsic, add support to it in the |
| 98 | <tt>canConstantFoldCallTo</tt> and <tt>ConstantFoldCall</tt> functions.</li> |
| 99 | |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 100 | <li><tt>llvm/test/Regression/*</tt>: Add test cases for your test cases to the |
| 101 | test suite</li> |
Chris Lattner | 3636540 | 2004-04-09 19:24:20 +0000 | [diff] [blame] | 102 | </ol> |
| 103 | |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 104 | <p>Once the intrinsic has been added to the system, you must add code generator |
| 105 | support for it. Generally you must do the following steps:</p> |
| 106 | |
| 107 | <dl> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 108 | |
Chris Lattner | 35dd5b0 | 2006-04-12 17:42:39 +0000 | [diff] [blame] | 109 | <dt>Add support to the .td file for the target(s) of your choice in |
| 110 | <tt>lib/Target/*/*.td</tt>.</dt> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 111 | |
Chris Lattner | 35dd5b0 | 2006-04-12 17:42:39 +0000 | [diff] [blame] | 112 | <dd>This is usually a matter of adding a pattern to the .td file that matches |
| 113 | the intrinsic, though it may obviously require adding the instructions you |
| 114 | want to generate as well. There are lots of examples in the PowerPC and X86 |
| 115 | backend to follow.</dd> |
Bill Wendling | 068da27 | 2007-09-22 10:07:00 +0000 | [diff] [blame] | 116 | </dl> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 117 | |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 118 | </div> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 119 | |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 120 | <!-- *********************************************************************** --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 121 | <h2> |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 122 | <a name="sdnode">Adding a new SelectionDAG node</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 123 | </h2> |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 124 | <!-- *********************************************************************** --> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 125 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 126 | <div> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 127 | |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 128 | <p>As with intrinsics, adding a new SelectionDAG node to LLVM is much easier |
| 129 | than adding a new instruction. New nodes are often added to help represent |
| 130 | instructions common to many targets. These nodes often map to an LLVM |
| 131 | instruction (add, sub) or intrinsic (byteswap, population count). In other |
| 132 | cases, new nodes have been added to allow many targets to perform a common task |
| 133 | (converting between floating point and integer representation) or capture more |
| 134 | complicated behavior in a single node (rotate).</p> |
Chris Lattner | 5eb9f0d | 2005-05-11 03:53:53 +0000 | [diff] [blame] | 135 | |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 136 | <ol> |
Duncan Sands | eb7fe5d | 2011-06-30 06:37:07 +0000 | [diff] [blame] | 137 | <li><tt>include/llvm/CodeGen/ISDOpcodes.h</tt>: |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 138 | Add an enum value for the new SelectionDAG node.</li> |
| 139 | <li><tt>lib/CodeGen/SelectionDAG/SelectionDAG.cpp</tt>: |
| 140 | Add code to print the node to <tt>getOperationName</tt>. If your new node |
| 141 | can be evaluated at compile time when given constant arguments (such as an |
| 142 | add of a constant with another constant), find the <tt>getNode</tt> method |
| 143 | that takes the appropriate number of arguments, and add a case for your node |
| 144 | to the switch statement that performs constant folding for nodes that take |
| 145 | the same number of arguments as your new node.</li> |
| 146 | <li><tt>lib/CodeGen/SelectionDAG/LegalizeDAG.cpp</tt>: |
| 147 | Add code to <a href="CodeGenerator.html#selectiondag_legalize">legalize, |
| 148 | promote, and expand</a> the node as necessary. At a minimum, you will need |
| 149 | to add a case statement for your node in <tt>LegalizeOp</tt> which calls |
| 150 | LegalizeOp on the node's operands, and returns a new node if any of the |
| 151 | operands changed as a result of being legalized. It is likely that not all |
| 152 | targets supported by the SelectionDAG framework will natively support the |
| 153 | new node. In this case, you must also add code in your node's case |
| 154 | statement in <tt>LegalizeOp</tt> to Expand your node into simpler, legal |
Chris Lattner | b5f6e25 | 2006-01-16 16:31:40 +0000 | [diff] [blame] | 155 | operations. The case for <tt>ISD::UREM</tt> for expanding a remainder into |
| 156 | a divide, multiply, and a subtract is a good example.</li> |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 157 | <li><tt>lib/CodeGen/SelectionDAG/LegalizeDAG.cpp</tt>: |
| 158 | If targets may support the new node being added only at certain sizes, you |
| 159 | will also need to add code to your node's case statement in |
| 160 | <tt>LegalizeOp</tt> to Promote your node's operands to a larger size, and |
| 161 | perform the correct operation. You will also need to add code to |
Chris Lattner | b5f6e25 | 2006-01-16 16:31:40 +0000 | [diff] [blame] | 162 | <tt>PromoteOp</tt> to do this as well. For a good example, see |
| 163 | <tt>ISD::BSWAP</tt>, |
Nate Begeman | 099d76c | 2006-01-16 07:54:23 +0000 | [diff] [blame] | 164 | which promotes its operand to a wider size, performs the byteswap, and then |
| 165 | shifts the correct bytes right to emulate the narrower byteswap in the |
| 166 | wider type.</li> |
| 167 | <li><tt>lib/CodeGen/SelectionDAG/LegalizeDAG.cpp</tt>: |
| 168 | Add a case for your node in <tt>ExpandOp</tt> to teach the legalizer how to |
| 169 | perform the action represented by the new node on a value that has been |
| 170 | split into high and low halves. This case will be used to support your |
| 171 | node with a 64 bit operand on a 32 bit target.</li> |
| 172 | <li><tt>lib/CodeGen/SelectionDAG/DAGCombiner.cpp</tt>: |
| 173 | If your node can be combined with itself, or other existing nodes in a |
| 174 | peephole-like fashion, add a visit function for it, and call that function |
| 175 | from <tt></tt>. There are several good examples for simple combines you |
| 176 | can do; <tt>visitFABS</tt> and <tt>visitSRL</tt> are good starting places. |
| 177 | </li> |
| 178 | <li><tt>lib/Target/PowerPC/PPCISelLowering.cpp</tt>: |
| 179 | Each target has an implementation of the <tt>TargetLowering</tt> class, |
| 180 | usually in its own file (although some targets include it in the same |
| 181 | file as the DAGToDAGISel). The default behavior for a target is to |
| 182 | assume that your new node is legal for all types that are legal for |
| 183 | that target. If this target does not natively support your node, then |
| 184 | tell the target to either Promote it (if it is supported at a larger |
| 185 | type) or Expand it. This will cause the code you wrote in |
| 186 | <tt>LegalizeOp</tt> above to decompose your new node into other legal |
| 187 | nodes for this target.</li> |
| 188 | <li><tt>lib/Target/TargetSelectionDAG.td</tt>: |
| 189 | Most current targets supported by LLVM generate code using the DAGToDAG |
| 190 | method, where SelectionDAG nodes are pattern matched to target-specific |
| 191 | nodes, which represent individual instructions. In order for the targets |
| 192 | to match an instruction to your new node, you must add a def for that node |
| 193 | to the list in this file, with the appropriate type constraints. Look at |
| 194 | <tt>add</tt>, <tt>bswap</tt>, and <tt>fadd</tt> for examples.</li> |
| 195 | <li><tt>lib/Target/PowerPC/PPCInstrInfo.td</tt>: |
| 196 | Each target has a tablegen file that describes the target's instruction |
| 197 | set. For targets that use the DAGToDAG instruction selection framework, |
| 198 | add a pattern for your new node that uses one or more target nodes. |
| 199 | Documentation for this is a bit sparse right now, but there are several |
| 200 | decent examples. See the patterns for <tt>rotl</tt> in |
| 201 | <tt>PPCInstrInfo.td</tt>.</li> |
| 202 | <li>TODO: document complex patterns.</li> |
| 203 | <li><tt>llvm/test/Regression/CodeGen/*</tt>: Add test cases for your new node |
| 204 | to the test suite. <tt>llvm/test/Regression/CodeGen/X86/bswap.ll</tt> is |
| 205 | a good example.</li> |
| 206 | </ol> |
Chris Lattner | 3636540 | 2004-04-09 19:24:20 +0000 | [diff] [blame] | 207 | |
| 208 | </div> |
| 209 | |
| 210 | <!-- *********************************************************************** --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 211 | <h2> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 212 | <a name="instruction">Adding a new instruction</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 213 | </h2> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 214 | <!-- *********************************************************************** --> |
| 215 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 216 | <div> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 217 | |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 218 | <p><span class="doc_warning">WARNING: adding instructions changes the bitcode |
Misha Brukman | b3b2827 | 2004-04-06 04:17:51 +0000 | [diff] [blame] | 219 | format, and it will take some effort to maintain compatibility with |
| 220 | the previous version.</span> Only add an instruction if it is absolutely |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 221 | necessary.</p> |
| 222 | |
| 223 | <ol> |
Misha Brukman | b3b2827 | 2004-04-06 04:17:51 +0000 | [diff] [blame] | 224 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 225 | <li><tt>llvm/include/llvm/Instruction.def</tt>: |
| 226 | add a number for your instruction and an enum name</li> |
| 227 | |
Misha Brukman | 47b14a4 | 2004-07-29 17:30:56 +0000 | [diff] [blame] | 228 | <li><tt>llvm/include/llvm/Instructions.h</tt>: |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 229 | add a definition for the class that will represent your instruction</li> |
| 230 | |
| 231 | <li><tt>llvm/include/llvm/Support/InstVisitor.h</tt>: |
| 232 | add a prototype for a visitor to your new instruction type</li> |
| 233 | |
| 234 | <li><tt>llvm/lib/AsmParser/Lexer.l</tt>: |
| 235 | add a new token to parse your instruction from assembly text file</li> |
| 236 | |
| 237 | <li><tt>llvm/lib/AsmParser/llvmAsmParser.y</tt>: |
| 238 | add the grammar on how your instruction can be read and what it will |
| 239 | construct as a result</li> |
| 240 | |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 241 | <li><tt>llvm/lib/Bitcode/Reader/Reader.cpp</tt>: |
| 242 | add a case for your instruction and how it will be parsed from bitcode</li> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 243 | |
| 244 | <li><tt>llvm/lib/VMCore/Instruction.cpp</tt>: |
| 245 | add a case for how your instruction will be printed out to assembly</li> |
| 246 | |
Chris Lattner | 8f36321 | 2004-07-29 17:31:57 +0000 | [diff] [blame] | 247 | <li><tt>llvm/lib/VMCore/Instructions.cpp</tt>: |
Misha Brukman | e39cd63 | 2004-09-28 16:58:12 +0000 | [diff] [blame] | 248 | implement the class you defined in |
| 249 | <tt>llvm/include/llvm/Instructions.h</tt></li> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 250 | |
Misha Brukman | a424228 | 2004-12-01 20:58:54 +0000 | [diff] [blame] | 251 | <li>Test your instruction</li> |
| 252 | |
| 253 | <li><tt>llvm/lib/Target/*</tt>: |
| 254 | Add support for your instruction to code generators, or add a lowering |
| 255 | pass.</li> |
| 256 | |
| 257 | <li><tt>llvm/test/Regression/*</tt>: add your test cases to the test suite.</li> |
| 258 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 259 | </ol> |
| 260 | |
| 261 | <p>Also, you need to implement (or modify) any analyses or passes that you want |
| 262 | to understand this new instruction.</p> |
| 263 | |
| 264 | </div> |
| 265 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 266 | |
| 267 | <!-- *********************************************************************** --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 268 | <h2> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 269 | <a name="type">Adding a new type</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 270 | </h2> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 271 | <!-- *********************************************************************** --> |
| 272 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 273 | <div> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 274 | |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 275 | <p><span class="doc_warning">WARNING: adding new types changes the bitcode |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 276 | format, and will break compatibility with currently-existing LLVM |
| 277 | installations.</span> Only add new types if it is absolutely necessary.</p> |
| 278 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 279 | <!-- ======================================================================= --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 280 | <h3> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 281 | <a name="fund_type">Adding a fundamental type</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 282 | </h3> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 283 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 284 | <div> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 285 | |
| 286 | <ol> |
| 287 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 288 | <li><tt>llvm/include/llvm/Type.h</tt>: |
Chris Lattner | 55f9501 | 2005-04-23 21:59:11 +0000 | [diff] [blame] | 289 | add enum for the new type; add static <tt>Type*</tt> for this type</li> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 290 | |
| 291 | <li><tt>llvm/lib/VMCore/Type.cpp</tt>: |
| 292 | add mapping from <tt>TypeID</tt> => <tt>Type*</tt>; |
| 293 | initialize the static <tt>Type*</tt></li> |
| 294 | |
| 295 | <li><tt>llvm/lib/AsmReader/Lexer.l</tt>: |
| 296 | add ability to parse in the type from text assembly</li> |
| 297 | |
| 298 | <li><tt>llvm/lib/AsmReader/llvmAsmParser.y</tt>: |
| 299 | add a token for that type</li> |
| 300 | |
| 301 | </ol> |
| 302 | |
| 303 | </div> |
| 304 | |
| 305 | <!-- ======================================================================= --> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 306 | <h3> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 307 | <a name="derived_type">Adding a derived type</a> |
NAKAMURA Takumi | 05d0265 | 2011-04-18 23:59:50 +0000 | [diff] [blame] | 308 | </h3> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 309 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 310 | <div> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 311 | |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 312 | <ol> |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 313 | <li><tt>llvm/include/llvm/Type.h</tt>: |
Chris Lattner | 55f9501 | 2005-04-23 21:59:11 +0000 | [diff] [blame] | 314 | add enum for the new type; add a forward declaration of the type |
Misha Brukman | 7cc8a89 | 2004-08-12 19:58:43 +0000 | [diff] [blame] | 315 | also</li> |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 316 | |
Chris Lattner | 47746aa | 2005-11-13 02:09:55 +0000 | [diff] [blame] | 317 | <li><tt>llvm/include/llvm/DerivedTypes.h</tt>: |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 318 | add new class to represent new class in the hierarchy; add forward |
| 319 | declaration to the TypeMap value type</li> |
| 320 | |
| 321 | <li><tt>llvm/lib/VMCore/Type.cpp</tt>: |
| 322 | add support for derived type to: |
Misha Brukman | 7cc8a89 | 2004-08-12 19:58:43 +0000 | [diff] [blame] | 323 | <div class="doc_code"> |
| 324 | <pre> |
| 325 | std::string getTypeDescription(const Type &Ty, |
| 326 | std::vector<const Type*> &TypeStack) |
| 327 | bool TypesEqual(const Type *Ty, const Type *Ty2, |
| 328 | std::map<const Type*, const Type*> & EqTypes) |
| 329 | </pre> |
| 330 | </div> |
| 331 | add necessary member functions for type, and factory methods</li> |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 332 | |
| 333 | <li><tt>llvm/lib/AsmReader/Lexer.l</tt>: |
| 334 | add ability to parse in the type from text assembly</li> |
| 335 | |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 336 | <li><tt>llvm/lib/BitCode/Writer/Writer.cpp</tt>: |
| 337 | modify <tt>void BitcodeWriter::outputType(const Type *T)</tt> to serialize |
Misha Brukman | 7cc8a89 | 2004-08-12 19:58:43 +0000 | [diff] [blame] | 338 | your type</li> |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 339 | |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 340 | <li><tt>llvm/lib/BitCode/Reader/Reader.cpp</tt>: |
| 341 | modify <tt>const Type *BitcodeReader::ParseType()</tt> to read your data |
Misha Brukman | 7cc8a89 | 2004-08-12 19:58:43 +0000 | [diff] [blame] | 342 | type</li> |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 343 | |
| 344 | <li><tt>llvm/lib/VMCore/AsmWriter.cpp</tt>: |
Misha Brukman | 7cc8a89 | 2004-08-12 19:58:43 +0000 | [diff] [blame] | 345 | modify |
| 346 | <div class="doc_code"> |
| 347 | <pre> |
| 348 | void calcTypeName(const Type *Ty, |
| 349 | std::vector<const Type*> &TypeStack, |
| 350 | std::map<const Type*,std::string> &TypeNames, |
| 351 | std::string & Result) |
| 352 | </pre> |
| 353 | </div> |
Chris Lattner | 8dad40c | 2004-08-12 19:06:24 +0000 | [diff] [blame] | 354 | to output the new derived type |
| 355 | </li> |
| 356 | |
| 357 | |
| 358 | </ol> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 359 | |
| 360 | </div> |
| 361 | |
NAKAMURA Takumi | f5af6ad | 2011-04-23 00:30:22 +0000 | [diff] [blame] | 362 | </div> |
| 363 | |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 364 | <!-- *********************************************************************** --> |
| 365 | |
| 366 | <hr> |
| 367 | <address> |
| 368 | <a href="http://jigsaw.w3.org/css-validator/check/referer"><img |
Misha Brukman | 4440870 | 2008-12-11 17:34:48 +0000 | [diff] [blame] | 369 | src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 370 | <a href="http://validator.w3.org/check/referer"><img |
Misha Brukman | f00ddb0 | 2008-12-11 18:23:24 +0000 | [diff] [blame] | 371 | src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 372 | |
NAKAMURA Takumi | b9a3363 | 2011-04-09 02:13:37 +0000 | [diff] [blame] | 373 | <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a> |
Misha Brukman | a3ce429 | 2004-04-06 03:53:49 +0000 | [diff] [blame] | 374 | <br> |
| 375 | Last modified: $Date$ |
| 376 | </address> |
| 377 | |
| 378 | </body> |
| 379 | </html> |