Author: kjs
Date: Sun Feb 24 11:12:47 2008
New Revision: 26048
Modified:
trunk/compilers/imcc/README
Log:
[docs] remove PIR language/syntax reference bits from imcc's readme; this is
not the place for that (there's enough material elsewhere). This file should
probably be merged into another file in docs/imcc, or deleted altogether.
Modified: trunk/compilers/imcc/README
==============================================================================
--- trunk/compilers/imcc/README (original)
+++ trunk/compilers/imcc/README Sun Feb 24 11:12:47 2008
@@ -25,15 +25,11 @@
So far, all the compiler does is register allocation and spilling. I like
Steve Muchnick's MIR language, and I'm taking a few things from it.
-Presently you can write code with unlimited symbolics or named
-locals and imcc will map them to ``physical'' registers.
-
I expect the IR compiler to be FAST, simple, and maintainable,
and never develop featuritis; however I want it to be adequate
for all languages targetting parrot. Did I mention that it
needs to be FAST?
-
Register Allocation
The allocator uses graph-coloring and du-chains to assign registers
@@ -56,127 +52,11 @@
C-based parsers are pretty darn fast. Currently assembling
Parrot on the fly is still relatively slow.
-
-More documentation
-
- s. the docs subdir
-
-
-Language Reference
-
-Variables, Registers and Constants
-
- Variables are simple identifiers, anything that is NOT a register
- or constant is a legal identifier. The syntax will have to change
- a bit to support Perl's non-alpha identifiers, which will probably
- spell renaming the registers.
-
- You may use an infinite number of typed temporaries.
- S=String, I=Int, N=Number, P=Object(or PMC)
-
- $S0 = 1
- $S1 = $S0 + 2
- ...
-
- You may also define lexicals with the .local directive below
- and use them by name.
-
- .local int i
- .local int j
- i = 4
- j = i * i
-
- Assigning to a constant is illegal syntax.
-
-Directives
-
- For this reference, I use the following legend:
- reg = A symbolic temporary ($S0, $I25)
- var = A named variable or symbol (i, foo, myArray)
- IDENTIFIER = An optionally quoted name
- lval = reg | var
- rval = reg | var | const
-
- lval is allowed as targets of instructions, but not constants,
- so we refer to operands on the right side as rvals. lvals
- are also used on the right hand side to indicate that the
- item can be a const or non-const token.
-
- These are tokens that might not directly translate to a specific
- opcode, and are intentionally left generic. Some of them aren't
- ops at all, but instructions to the compiler.
-
- .sym <type> <IDENTIFIER>
-
- .sub <IDENTIFIER>
- .end
-
- .local <type> <IDENTIFIER>
-
- .return '(' <rval> ')'
-
- .param <type> <lval>
-
- .emit
-
- .eom
-
-
-Instructions
-
- Assignments, calls, branches, etc. Simplified forms of lower
- level operations. Typically is 1-to-1 or 1-to-2 instruction to
- Parrot ratio.
-
-
- lval = rval
-
- lval = rval + rval
-
- lval = rval - rval
-
- lval = rval * rval
-
- lval = rval / rval
-
- lval = rval % rval
-
- lval = rval << rval
-
- lval = rval >> rval
-
- <S.lval> = <S.rval> . <S.rval>
-
- For array and string access you can use:
-
- <S.lval|P.lval> [ rval ] = rval
-
- lval = <S.lval|P.lval> [ rval ]
-
- <P.lval> = new <TYPE>
-
- dec <lval>
-
- inc <lval>
-
- end
-
- goto <LABEL>
-
- if <expression> goto <LABEL>
-
- print rval
-
-
Instructions not known to imcc are looked up in parrot's
op_info_table and must have the proper amount and types of
arguments.
-The best way to learn PIR quickly is to study the examples
-in examples/tutorial.
-
-
Please mail [EMAIL PROTECTED] with bug-reports or patches.
