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Add glossary entries for IL and IR.

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This commit is contained in:
Jakob Stoklund Olesen
2016-11-02 09:58:02 -07:00
parent bfeb9e4839
commit 0b7010e367
1 changed files with 26 additions and 12 deletions
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docs/langref.rst
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@@ -5,10 +5,10 @@ Cretonne Language Reference
.. default-domain:: cton .. default-domain:: cton
.. highlight:: cton .. highlight:: cton
The Cretonne intermediate language has two equivalent representations: an The Cretonne intermediate language (:term:`IL`) has two equivalent
*in-memory data structure* that the code generator library is using, and representations: an *in-memory data structure* that the code generator library
a *text format* which is used for test cases and debug output. Files containing is using, and a *text format* which is used for test cases and debug output.
Cretonne textual IL have the ``.cton`` filename extension. Files containing Cretonne textual IL have the ``.cton`` filename extension.
This reference uses the text format to describe IL semantics but glosses over This reference uses the text format to describe IL semantics but glosses over
the finer details of the lexical and syntactic structure of the format. the finer details of the lexical and syntactic structure of the format.
@@ -76,9 +76,9 @@ variable during each iteration. Finally, ``v12`` is computed as the induction
variable value for the next iteration. variable value for the next iteration.
It can be difficult to generate correct SSA form if the program being converted It can be difficult to generate correct SSA form if the program being converted
into Cretonne IL contains multiple assignments to the same variables. Such into Cretonne :term:`IL` contains multiple assignments to the same variables.
variables can be presented to Cretonne as :term:`stack slot`\s instead. Stack Such variables can be presented to Cretonne as :term:`stack slot`\s instead.
slots are accessed with the :inst:`stack_store` and :inst:`stack_load` Stack slots are accessed with the :inst:`stack_store` and :inst:`stack_load`
instructions which behave more like variable accesses in a typical programming instructions which behave more like variable accesses in a typical programming
language. Cretonne can perform the necessary dataflow analysis to convert stack language. Cretonne can perform the necessary dataflow analysis to convert stack
slots to SSA form. slots to SSA form.
@@ -275,11 +275,11 @@ indicate the different kinds of immediate operands on an instruction.
A floating point condition code. See the :inst:`fcmp` instruction for details. A floating point condition code. See the :inst:`fcmp` instruction for details.
The two IEEE floating point immediate types :type:`ieee32` and :type:`ieee64` The two IEEE floating point immediate types :type:`ieee32` and :type:`ieee64`
are displayed as hexadecimal floating point literals in the textual IL format. are displayed as hexadecimal floating point literals in the textual :term:`IL`
Decimal floating point literals are not allowed because some computer systems format. Decimal floating point literals are not allowed because some computer
can round differently when converting to binary. The hexadecimal floating point systems can round differently when converting to binary. The hexadecimal
format is mostly the same as the one used by C99, but extended to represent all floating point format is mostly the same as the one used by C99, but extended
NaN bit patterns: to represent all NaN bit patterns:
Normal numbers Normal numbers
Compatible with C99: ``-0x1.Tpe`` where ``T`` are the trailing Compatible with C99: ``-0x1.Tpe`` where ``T`` are the trailing
@@ -859,6 +859,20 @@ Glossary
.. glossary:: .. glossary::
intermediate language
IL
The language used to describe functions to Cretonne. This reference
describes the syntax and semantics of the Cretonne IL. The IL has two
forms: Textual and an in-memory intermediate representation
(:term:`IR`).
intermediate representation
IR
The in-memory representation of :term:`IL`. The data structures
Cretonne uses to represent a program internally are called the
intermediate representation. Cretonne's IR can be converted to text
losslessly.
function signature function signature
A function signature describes how to call a function. It consists of: A function signature describes how to call a function. It consists of: