Mercurial > hg > CbC > CbC_llvm
diff docs/tutorial/OCamlLangImpl3.rst @ 100:7d135dc70f03 LLVM 3.9
LLVM 3.9
author | Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> |
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date | Tue, 26 Jan 2016 22:53:40 +0900 |
parents | afa8332a0e37 |
children |
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--- a/docs/tutorial/OCamlLangImpl3.rst Tue Oct 13 17:49:56 2015 +0900 +++ b/docs/tutorial/OCamlLangImpl3.rst Tue Jan 26 22:53:40 2016 +0900 @@ -114,8 +114,8 @@ arguments. This code simply checks to see that the specified name is in the map (if not, an unknown variable is being referenced) and returns the value for it. In future chapters, we'll add support for `loop -induction variables <LangImpl5.html#for>`_ in the symbol table, and for -`local variables <LangImpl7.html#localvars>`_. +induction variables <LangImpl5.html#for-loop-expression>`_ in the symbol table, and for +`local variables <LangImpl7.html#user-defined-local-variables>`_. .. code-block:: ocaml @@ -152,22 +152,22 @@ suffix. Local value names for instructions are purely optional, but it makes it much easier to read the IR dumps. -`LLVM instructions <../LangRef.html#instref>`_ are constrained by strict +`LLVM instructions <../LangRef.html#instruction-reference>`_ are constrained by strict rules: for example, the Left and Right operators of an `add -instruction <../LangRef.html#i_add>`_ must have the same type, and the +instruction <../LangRef.html#add-instruction>`_ must have the same type, and the result type of the add must match the operand types. Because all values in Kaleidoscope are doubles, this makes for very simple code for add, sub and mul. On the other hand, LLVM specifies that the `fcmp -instruction <../LangRef.html#i_fcmp>`_ always returns an 'i1' value (a +instruction <../LangRef.html#fcmp-instruction>`_ always returns an 'i1' value (a one bit integer). The problem with this is that Kaleidoscope wants the value to be a 0.0 or 1.0 value. In order to get these semantics, we combine the fcmp instruction with a `uitofp -instruction <../LangRef.html#i_uitofp>`_. This instruction converts its +instruction <../LangRef.html#uitofp-to-instruction>`_. This instruction converts its input integer into a floating point value by treating the input as an unsigned value. In contrast, if we used the `sitofp -instruction <../LangRef.html#i_sitofp>`_, the Kaleidoscope '<' operator +instruction <../LangRef.html#sitofp-to-instruction>`_, the Kaleidoscope '<' operator would return 0.0 and -1.0, depending on the input value. .. code-block:: ocaml @@ -196,7 +196,7 @@ Once we have the function to call, we recursively codegen each argument that is to be passed in, and create an LLVM `call -instruction <../LangRef.html#i_call>`_. Note that LLVM uses the native C +instruction <../LangRef.html#call-instruction>`_. Note that LLVM uses the native C calling conventions by default, allowing these calls to also call into standard library functions like "sin" and "cos", with no additional effort. @@ -253,7 +253,7 @@ This indicates the type and name to use, as well as which module to insert into. By default we assume a function has ``Llvm.Linkage.ExternalLinkage``. "`external -linkage <LangRef.html#linkage>`_" means that the function may be defined +linkage <../LangRef.html#linkage>`_" means that the function may be defined outside the current module and/or that it is callable by functions outside the module. The "``name``" passed in is the name the user specified: this name is registered in "``Codegen.the_module``"s symbol @@ -360,7 +360,7 @@ method for the root expression of the function. If no error happens, this emits code to compute the expression into the entry block and returns the value that was computed. Assuming no error, we then create -an LLVM `ret instruction <../LangRef.html#i_ret>`_, which completes the +an LLVM `ret instruction <../LangRef.html#ret-instruction>`_, which completes the function. Once the function is built, we call ``Llvm_analysis.assert_valid_function``, which is provided by LLVM. This function does a variety of consistency checks on the generated code, to @@ -413,10 +413,10 @@ Note how the parser turns the top-level expression into anonymous functions for us. This will be handy when we add `JIT -support <OCamlLangImpl4.html#jit>`_ in the next chapter. Also note that +support <OCamlLangImpl4.html#adding-a-jit-compiler>`_ in the next chapter. Also note that the code is very literally transcribed, no optimizations are being performed. We will `add -optimizations <OCamlLangImpl4.html#trivialconstfold>`_ explicitly in the +optimizations <OCamlLangImpl4.html#trivial-constant-folding>`_ explicitly in the next chapter. ::