55 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			55 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Factor
		
	
	
| ! Copyright (C) 2008, 2010 Slava Pestov.
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| ! See http://factorcode.org/license.txt for BSD license.
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| USING: assocs arrays namespaces sequences kernel definitions
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| math effects accessors words fry classes.algebra
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| compiler.units stack-checker.values stack-checker.visitor
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| stack-checker.errors ;
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| IN: stack-checker.state
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| 
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| ! Did the current control-flow path throw an error?
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| SYMBOL: terminated?
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| 
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| ! Number of inputs current word expects from the stack
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| SYMBOL: input-count
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| SYMBOL: inner-d-index
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| 
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| DEFER: commit-literals
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| 
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| ! Compile-time data stack
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| : meta-d ( -- stack ) commit-literals \ meta-d get ;
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| 
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| ! Compile-time retain stack
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| : meta-r ( -- stack ) \ meta-r get ;
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| 
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| ! Uncommitted literals. This is a form of local dead-code
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| ! elimination; the goal is to reduce the number of IR nodes
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| ! which get constructed. Technically it is redundant since
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| ! we do global DCE later, but it speeds up compile time.
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| SYMBOL: literals
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| 
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| : (push-literal) ( obj -- )
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|     dup <literal> make-known
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|     [ nip \ meta-d get push ] [ #push, ] 2bi ;
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| 
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| : commit-literals ( -- )
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|     literals get [
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|         [ [ (push-literal) ] each ] [ delete-all ] bi
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|     ] unless-empty ;
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| 
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| : current-stack-height ( -- n ) meta-d length input-count get - ;
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| 
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| : current-effect ( -- effect )
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|     input-count get "x" <array>
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|     meta-d length "x" <array>
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|     terminated? get <terminated-effect> ;
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| 
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| : check-effect ( required-effect -- )
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|     [ current-effect ] dip 2dup effect<= [ 2drop ] [ effect-error ] if ;
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| 
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| : init-inference ( -- )
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|     terminated? off
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|     V{ } clone \ meta-d set
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|     V{ } clone literals set
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|     0 input-count set
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|     0 inner-d-index set ;
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