From 53e9355c2e91561b71c89a0b79eb3f3d2645b02f Mon Sep 17 00:00:00 2001
From: dos-reis <gdr@axiomatics.org>
Date: Tue, 29 Nov 2011 10:55:55 +0000
Subject: * interp/g-opt.boot (isSimpleForm): Remove as unused.
(floatableVMForm?): New. (modified?): Rename form varIsAssigned.
(canInlineVarDefinition): Tidy. Allow intermediate temporaries
initialized from variables to be inlined if not modified. (optBind):
Tidy.
---
src/ChangeLog | 9 ++++++++
src/interp/g-opt.boot | 59 +++++++++++++++++++++++----------------------------
2 files changed, 36 insertions(+), 32 deletions(-)
(limited to 'src')
diff --git a/src/ChangeLog b/src/ChangeLog
index 7997147d..ae9597dd 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,12 @@
+2011-11-29 Gabriel Dos Reis <gdr@cs.tamu.edu>
+
+ * interp/g-opt.boot (isSimpleForm): Remove as unused.
+ (floatableVMForm?): New.
+ (modified?): Rename form varIsAssigned.
+ (canInlineVarDefinition): Tidy. Allow intermediate temporaries
+ initialized from variables to be inlined if not modified.
+ (optBind): Tidy.
+
2011-11-28 Gabriel Dos Reis <gdr@cs.tamu.edu>
* interp/nruncomp.boot (genDeltaEntry): Use $ for the domain of
diff --git a/src/interp/g-opt.boot b/src/interp/g-opt.boot
index 0a7d1678..a859c67a 100644
--- a/src/interp/g-opt.boot
+++ b/src/interp/g-opt.boot
@@ -459,9 +459,8 @@ $VMsideEffectFreeOperators ==
++ List of simple VM operators
$simpleVMoperators ==
- append($VMsideEffectFreeOperators,
- ['SPADCALL,'%apply, '%gensym, '%lreverse!,
- '%strstc])
+ [:$VMsideEffectFreeOperators,
+ :['SPADCALL,'%apply, '%gensym, '%lreverse!, '%strstc]]
++ Return true if the `form' is semi-simple with respect to
++ to the list of operators `ops'.
@@ -477,20 +476,14 @@ semiSimpleRelativeTo?(form,ops) ==
sideEffectFree? form ==
semiSimpleRelativeTo?(form,$VMsideEffectFreeOperators)
-++ Return true if `form' is a simple VM form.
-++ See $simpleVMoperators for the definition of simple operators.
-isSimpleVMForm form ==
- semiSimpleRelativeTo?(form,$simpleVMoperators)
-
++ Return true if `form' is a VM form whose evaluation does not depend
-++ on the program point where it is evaluated.
-isFloatableVMForm: %Code -> %Boolean
-isFloatableVMForm form ==
- form isnt [.,:.] => form isnt "$"
- form is ['QUOTE,:.] => true
- symbolMember?(form.op, $simpleVMoperators) and
- "and"/[isFloatableVMForm arg for arg in form.args]
-
+++ on the program point where it is evaluated.
+$FloatableOperators ==
+ ['%bind,:$VMsideEffectFreeOperators]
+
+floatableVMForm?: %Code -> %Boolean
+floatableVMForm? form ==
+ semiSimpleRelativeTo?(form,$FloatableOperators)
++ Return true if the VM form `form' is one that we certify to
++ evaluate to a (compile time) constant. Note that this is a
@@ -514,12 +507,12 @@ findVMFreeVars form ==
++ Return true is `var' is the left hand side of an assignment
++ in `form'.
-varIsAssigned(var,form) ==
+modified?(var,form) ==
atomic? form => false
form is [op,var',:.] and op in '(%LET LETT SETQ %store) =>
symbol? var' => var' = var -- whole var is assigned
var' is [.,=var] -- only part of it is modified
- or/[varIsAssigned(var,f) for f in form]
+ or/[modified?(var,f) for f in form]
++ Return the list of variables referenced in `expr'.
@@ -544,22 +537,25 @@ canInlineVarDefinition(var,expr,body) ==
gensym? var and sameObject?(var,body) => true
-- FIXME: We should not be inlining a side-effecting initializer.
-- If the variable is assigned to, that is a no no.
- varIsAssigned(var,body) => false
+ modified?(var,body) => false
-- Similarly, if the initial value depends on variables that are
- -- side-effected latter, it is alos a no no.
- or/[varIsAssigned(x,body) for x in dependentVars expr] => false
- -- Conversatively preserve order of inialization
- cons? body and body.op in '(%bind LET %loop %collect) => false
+ -- side-effected latter, it is also a no no.
+ or/[modified?(x,body) for x in dependentVars expr] => false
+ -- If the initializer is a variable and not modified in body,
+ -- and the new var is not modified, then we can inline.
+ ident? expr => true
+ -- Conversatively stay out of loops
+ cons? body and body.op in '(%loop %collect) => false
-- Linearly used internal temporaries should be replaced, and
-- so should side-effet free initializers for linear variables.
usageCount := numOfOccurencesOf(var,body)
- usageCount < 2 and sideEffectFree? expr => true
+ usageCount < 2 and floatableVMForm? expr => true
gensym? var and usageCount = 1 => true
-- If the initializer is a variable and the body is
- -- a series of choices with side-effect free predicates, then
- -- no harm is done by removing the local `var'.
+ -- a series of choices with floatable predicates, then
+ -- no harm is done by inlining the local `var'.
ident? expr and body is ['%when,:branches] =>
- and/[sideEffectFree? pred for [pred,:.] in branches]
+ and/[floatableVMForm? pred for [pred,:.] in branches]
false
++ Implement simple-minded LET-inlining. It seems we can't count
@@ -569,21 +565,20 @@ canInlineVarDefinition(var,expr,body) ==
++ have a type directed compilation throughout.
optBind form ==
form isnt ['%bind,inits,.] => form -- accept only simple bodies
- ok := true
- while ok and inits ~= nil repeat
+ while inits ~= nil repeat
[var,expr] := first inits
- usedSymbol?(var,rest inits) => ok := false -- no dependency, please.
+ usedSymbol?(var,rest inits) => leave nil -- no dependency, please.
body := third form
canInlineVarDefinition(var,expr,body) =>
third(form) := substitute!(expr,var,body)
inits := rest inits
- ok := false
+ leave nil
null inits => third form -- no local var left
second(form) := inits
form
optTry form ==
- form isnt ['%try,e,hs,f] or not(isFloatableVMForm e) or f ~= nil => form
+ form isnt ['%try,e,hs,f] or not(floatableVMForm? e) or f ~= nil => form
e
optList form ==
--
cgit v1.2.3