<title>Kaleidoscope: Implementing code generation to LLVM IR</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="author" content="Chris Lattner">
- <link rel="stylesheet" href="../llvm.css" type="text/css">
+ <link rel="stylesheet" href="../_static/llvm.css" type="text/css">
</head>
<body>
-<div class="doc_title">Kaleidoscope: Code generation to LLVM IR</div>
+<h1>Kaleidoscope: Code generation to LLVM IR</h1>
<ul>
<li><a href="index.html">Up to Tutorial Index</a></li>
</div>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="intro">Chapter 3 Introduction</a></div>
+<h2><a name="intro">Chapter 3 Introduction</a></h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>Welcome to Chapter 3 of the "<a href="index.html">Implementing a language
with LLVM</a>" tutorial. This chapter shows you how to transform the <a
</div>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="basics">Code Generation Setup</a></div>
+<h2><a name="basics">Code Generation Setup</a></h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>
In order to generate LLVM IR, we want some simple setup to get started. First
</div>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="exprs">Expression Code Generation</a></div>
+<h2><a name="exprs">Expression Code Generation</a></h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>Generating LLVM code for expression nodes is very straightforward: less
than 45 lines of commented code for all four of our expression nodes. First
if (L == 0 || R == 0) return 0;
switch (Op) {
- case '+': return Builder.CreateAdd(L, R, "addtmp");
- case '-': return Builder.CreateSub(L, R, "subtmp");
- case '*': return Builder.CreateMul(L, R, "multmp");
+ case '+': return Builder.CreateFAdd(L, R, "addtmp");
+ case '-': return Builder.CreateFSub(L, R, "subtmp");
+ case '*': return Builder.CreateFMul(L, R, "multmp");
case '<':
L = Builder.CreateFCmpULT(L, R, "cmptmp");
// Convert bool 0/1 to double 0.0 or 1.0
<p>In the example above, the LLVM builder class is starting to show its value.
IRBuilder knows where to insert the newly created instruction, all you have to
-do is specify what instruction to create (e.g. with <tt>CreateAdd</tt>), which
+do is specify what instruction to create (e.g. with <tt>CreateFAdd</tt>), which
operands to use (<tt>L</tt> and <tt>R</tt> here) and optionally provide a name
for the generated instruction.</p>
if (ArgsV.back() == 0) return 0;
}
- return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
+ return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
}
</pre>
</div>
</div>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="funcs">Function Code Generation</a></div>
+<h2><a name="funcs">Function Code Generation</a></h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>Code generation for prototypes and functions must handle a number of
details, which make their code less beautiful than expression code
<pre>
Function *PrototypeAST::Codegen() {
// Make the function type: double(double,double) etc.
- std::vector<const Type*> Doubles(Args.size(),
- Type::getDoubleTy(getGlobalContext()));
+ std::vector<Type*> Doubles(Args.size(),
+ Type::getDoubleTy(getGlobalContext()));
FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
Doubles, false);
-
+
Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
</pre>
</div>
</div>
<p>The Module symbol table works just like the Function symbol table when it
-comes to name conflicts: if a new function is created with a name was previously
-added to the symbol table, it will get implicitly renamed when added to the
+comes to name conflicts: if a new function is created with a name that was previously
+added to the symbol table, the new function will get implicitly renamed when added to the
Module. The code above exploits this fact to determine if there was a previous
definition of this function.</p>
</div>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="driver">Driver Changes and
-Closing Thoughts</a></div>
+<h2><a name="driver">Driver Changes and Closing Thoughts</a></h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>
For now, code generation to LLVM doesn't really get us much, except that we can
<pre>
ready> <b>4+5</b>;
Read top-level expression:
-define double @""() {
+define double @0() {
entry:
- ret double 9.000000e+00
+ ret double 9.000000e+00
}
</pre>
</div>
Read function definition:
define double @foo(double %a, double %b) {
entry:
- %multmp = fmul double %a, %a
- %multmp1 = fmul double 2.000000e+00, %a
- %multmp2 = fmul double %multmp1, %b
- %addtmp = fadd double %multmp, %multmp2
- %multmp3 = fmul double %b, %b
- %addtmp4 = fadd double %addtmp, %multmp3
- ret double %addtmp4
+ %multmp = fmul double %a, %a
+ %multmp1 = fmul double 2.000000e+00, %a
+ %multmp2 = fmul double %multmp1, %b
+ %addtmp = fadd double %multmp, %multmp2
+ %multmp3 = fmul double %b, %b
+ %addtmp4 = fadd double %addtmp, %multmp3
+ ret double %addtmp4
}
</pre>
</div>
Read function definition:
define double @bar(double %a) {
entry:
- %calltmp = call double @foo( double %a, double 4.000000e+00 )
- %calltmp1 = call double @bar( double 3.133700e+04 )
- %addtmp = fadd double %calltmp, %calltmp1
- ret double %addtmp
+ %calltmp = call double @foo(double %a, double 4.000000e+00)
+ %calltmp1 = call double @bar(double 3.133700e+04)
+ %addtmp = fadd double %calltmp, %calltmp1
+ ret double %addtmp
}
</pre>
</div>
ready> <b>cos(1.234);</b>
Read top-level expression:
-define double @""() {
+define double @1() {
entry:
- %calltmp = call double @cos( double 1.234000e+00 )
- ret double %calltmp
+ %calltmp = call double @cos(double 1.234000e+00)
+ ret double %calltmp
}
</pre>
</div>
ready> <b>^D</b>
; ModuleID = 'my cool jit'
-define double @""() {
+define double @0() {
entry:
- %addtmp = fadd double 4.000000e+00, 5.000000e+00
- ret double %addtmp
+ %addtmp = fadd double 4.000000e+00, 5.000000e+00
+ ret double %addtmp
}
define double @foo(double %a, double %b) {
entry:
- %multmp = fmul double %a, %a
- %multmp1 = fmul double 2.000000e+00, %a
- %multmp2 = fmul double %multmp1, %b
- %addtmp = fadd double %multmp, %multmp2
- %multmp3 = fmul double %b, %b
- %addtmp4 = fadd double %addtmp, %multmp3
- ret double %addtmp4
+ %multmp = fmul double %a, %a
+ %multmp1 = fmul double 2.000000e+00, %a
+ %multmp2 = fmul double %multmp1, %b
+ %addtmp = fadd double %multmp, %multmp2
+ %multmp3 = fmul double %b, %b
+ %addtmp4 = fadd double %addtmp, %multmp3
+ ret double %addtmp4
}
define double @bar(double %a) {
entry:
- %calltmp = call double @foo( double %a, double 4.000000e+00 )
- %calltmp1 = call double @bar( double 3.133700e+04 )
- %addtmp = fadd double %calltmp, %calltmp1
- ret double %addtmp
+ %calltmp = call double @foo(double %a, double 4.000000e+00)
+ %calltmp1 = call double @bar(double 3.133700e+04)
+ %addtmp = fadd double %calltmp, %calltmp1
+ ret double %addtmp
}
declare double @cos(double)
-define double @""() {
+define double @1() {
entry:
- %calltmp = call double @cos( double 1.234000e+00 )
- ret double %calltmp
+ %calltmp = call double @cos(double 1.234000e+00)
+ ret double %calltmp
}
</pre>
</div>
<!-- *********************************************************************** -->
-<div class="doc_section"><a name="code">Full Code Listing</a></div>
+<h2><a name="code">Full Code Listing</a></h2>
<!-- *********************************************************************** -->
-<div class="doc_text">
+<div>
<p>
Here is the complete code listing for our running example, enhanced with the
<div class="doc_code">
<pre>
- # Compile
- g++ -g -O3 toy.cpp `llvm-config --cppflags --ldflags --libs core` -o toy
- # Run
- ./toy
+# Compile
+clang++ -g -O3 toy.cpp `llvm-config --cppflags --ldflags --libs core` -o toy
+# Run
+./toy
</pre>
</div>
// See example below.
#include "llvm/DerivedTypes.h"
+#include "llvm/IRBuilder.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Analysis/Verifier.h"
-#include "llvm/Support/IRBuilder.h"
#include <cstdio>
#include <string>
#include <map>
if (L == 0 || R == 0) return 0;
switch (Op) {
- case '+': return Builder.CreateAdd(L, R, "addtmp");
- case '-': return Builder.CreateSub(L, R, "subtmp");
- case '*': return Builder.CreateMul(L, R, "multmp");
+ case '+': return Builder.CreateFAdd(L, R, "addtmp");
+ case '-': return Builder.CreateFSub(L, R, "subtmp");
+ case '*': return Builder.CreateFMul(L, R, "multmp");
case '<':
L = Builder.CreateFCmpULT(L, R, "cmptmp");
// Convert bool 0/1 to double 0.0 or 1.0
if (ArgsV.back() == 0) return 0;
}
- return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
+ return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
}
Function *PrototypeAST::Codegen() {
// Make the function type: double(double,double) etc.
- std::vector<const Type*> Doubles(Args.size(),
- Type::getDoubleTy(getGlobalContext()));
+ std::vector<Type*> Doubles(Args.size(),
+ Type::getDoubleTy(getGlobalContext()));
FunctionType *FT = FunctionType::get(Type::getDoubleTy(getGlobalContext()),
Doubles, false);
src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
- <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
+ <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Last modified: $Date$
</address>
</body>
projects / oota-llvm.git / blobdiff