+ IMC |
Tried to give a sense of what PIR does without being a tutorial or reference manual |
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{{future software}} |
{{future software}} |
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The '''Parrot intermediate representation''' or '''PIR''', |
The '''Parrot intermediate representation''' or '''PIR''', previously called Intermediate code (IMC), is one of the two assembly languages for the [[Parrot virtual machine]]. The other is [[Parrot assembly language]] or PASM. Compared to [[PASM]], PIR exists at a slightly higher level of abstraction, and provides temporary registers and named registers, simplifying code genaration. |
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While parrot is still evovling, it is currently being used in many different capacities, and has undergone several releases. |
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==Overview== |
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PIR provides a set of abstractions that allow the programmer to ignore certain redundancies in the Parrot bytecode and quickly write code that adheres to the the complexities of Parrot, such as the calling conventions. |
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===Abstractions=== |
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PIR provides both type abstraction and polymorphism to some degree. For example, the "<code>+</code>" operator can be used with <code>int</code>, <code>num</code> or both: |
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.local int a |
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.local num b |
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a = 1 |
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b = 1.1 |
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.local num c |
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c = a + b |
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===Calling conventions=== |
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The calling conventions in Parrot are fairly complex, but all of that complexity can be hidden by using PIR macros: |
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.sub foo |
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.param int a |
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.param int b |
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.local int tmp |
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tmp = a + b |
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.return tmp |
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.end |
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Each of these macros that begins with a "<code>.</code>" expands out to the required Parrot bytecode, but does not directly represent any fundamental Parrot operation. |
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==Example== |
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The [[hello world program]] in PIR is |
The [[hello world program]] in PIR is |
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<code><pre> |
<code><pre> |
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.sub hello |
.sub hello :main |
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print "Hello world!\n" |
print "Hello world!\n" |
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.end</pre></code> |
.end</pre></code> |
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If the program is saved as ''hello.pir'', it can be compiled and executed with this command: <code>parrot hello.pir</code> |
If the program is saved as ''hello.pir'', it can be compiled and executed with this command: <code>parrot hello.pir</code> |
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==External |
==External links== |
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*[http://svn.perl.org/parrot/trunk/docs/pir-tutorial.pod The PIR tutorial in the Parrot subversion repository] |
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*[http://www.parrotcode.org/examples/pir.html PIR examples at ParrotCode] |
*[http://www.parrotcode.org/examples/pir.html PIR examples at ParrotCode] |
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Revision as of 19:56, 7 July 2006
Template:Future software The Parrot intermediate representation or PIR, previously called Intermediate code (IMC), is one of the two assembly languages for the Parrot virtual machine. The other is Parrot assembly language or PASM. Compared to PASM, PIR exists at a slightly higher level of abstraction, and provides temporary registers and named registers, simplifying code genaration.
While parrot is still evovling, it is currently being used in many different capacities, and has undergone several releases.
Overview
PIR provides a set of abstractions that allow the programmer to ignore certain redundancies in the Parrot bytecode and quickly write code that adheres to the the complexities of Parrot, such as the calling conventions.
Abstractions
PIR provides both type abstraction and polymorphism to some degree. For example, the "+
" operator can be used with int
, num
or both:
.local int a .local num b a = 1 b = 1.1 .local num c c = a + b
Calling conventions
The calling conventions in Parrot are fairly complex, but all of that complexity can be hidden by using PIR macros:
.sub foo .param int a .param int b .local int tmp tmp = a + b .return tmp .end
Each of these macros that begins with a ".
" expands out to the required Parrot bytecode, but does not directly represent any fundamental Parrot operation.
Example
The hello world program in PIR is
.sub hello :main
print "Hello world!\n"
.end
If the program is saved as hello.pir, it can be compiled and executed with this command: parrot hello.pir