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authordos-reis <gdr@axiomatics.org>2011-09-10 14:24:58 +0000
committerdos-reis <gdr@axiomatics.org>2011-09-10 14:24:58 +0000
commit65da3e37db268624267dd0a0a6c2026ba8fb561a (patch)
tree824243673bf2426151a10a3b146dcf8c515c4eb5 /src/interp
parentcc4c6a9e4cc71d63143037da74c11271640ae8fb (diff)
downloadopen-axiom-65da3e37db268624267dd0a0a6c2026ba8fb561a.tar.gz
* interp/g-opt.boot (doInlineCall): New.
(optCall): Use it to implement inline functions. ($VMsideEffectFreeOperators): Include %apply and STRINGIMAGE. ($simpleVMoperators): STRINGIMAGE is promoted. (canInlineVarDefinition): Tidy. (optBind): Likewise.
Diffstat (limited to 'src/interp')
-rw-r--r--src/interp/g-opt.boot49
1 files changed, 43 insertions, 6 deletions
diff --git a/src/interp/g-opt.boot b/src/interp/g-opt.boot
index 7e754db3..27811638 100644
--- a/src/interp/g-opt.boot
+++ b/src/interp/g-opt.boot
@@ -256,12 +256,47 @@ optSPADCALL(form is ['SPADCALL,:argl]) ==
argl is [:argl,fun] and fun is ["ELT",dom,slot] =>
optCall ['%call,['ELT,dom,slot],:argl]
form
-
+
+++ Inline a call with arguments `args' to a simple function with
+++ parameter-list `parms' and body `body'.
+doInlineCall(args,parms,body) ==
+ -- 1. almost constant functions are easy
+ parms = nil => body
+ -- 2. identity functions too
+ parms is [=body] => first args
+ -- 3. We know that the body is essentially side-effect-free (at best)
+ -- or simple expression (at worst.) The issue is whether it is
+ -- OK to directly substitute the arguments which may be
+ -- arbitrary expressions. The ideal semantics calls for introducting
+ -- a (fresh) temporary to hold the values of the argument expressions.
+ -- We attempt to short-circuit the native evaluation as follows:
+ -- a. side-effect-free arguments go by themselves.
+ -- b. Simple expression arguments go by themselves as long as
+ -- the corresponding parameter is used linearly in the body.
+ -- c. Others get evaluated to temporaries.
+ tmps := nil -- list of temporaries
+ inits := nil -- list of local bindings
+ subst := nil -- arguments substitution.
+ for arg in args for parm in parms repeat
+ g := gensym()
+ tmps := [g,:tmps]
+ sideEffectFree? arg
+ or (numOfOccurencesOf(parm,body) < 2 and isSimpleVMForm body) =>
+ subst := [[g,:arg],:subst]
+ inits := [[g,arg],:inits]
+ -- 4. Alpha-rename the body and substitute simple expression arguments.
+ body := applySubst(pairList(parms,reverse! tmps),body)
+ body := applySubst!(subst,body)
+ -- 5. Deliver.
+ inits = nil => body
+ ['%bind,reverse! inits,body]
+
+
optCall (x is ['%call,:u]) ==
u is [['XLAM,vars,body],:args] =>
vars isnt [.,:.] => body
#vars > #args => systemErrorHere ['optCall,x]
- resetTo(x,applySubst(pairList(vars,args),body))
+ resetTo(x,doInlineCall(args,vars,body))
[fn,:a] := u
fn isnt [.,:.] =>
opt := fn has OPTIMIZE => resetTo(x,FUNCALL(opt,u))
@@ -383,7 +418,7 @@ optSuchthat [.,:u] == ["SUCHTHAT",:u]
++ List of VM side effect free operators.
$VMsideEffectFreeOperators ==
- '(FUNCALL
+ '(FUNCALL %apply
SPADfirst ASH FLOAT_-RADIX FLOAT FLOAT_-SIGN
%funcall %nothing %when %false %true %otherwise %2bit %2bool
%and %or %not %peq %ieq %ilt %ile %igt %ige %head %tail %integer?
@@ -402,7 +437,7 @@ $VMsideEffectFreeOperators ==
%zexp %zlog %zsin %zcos %ztan %zasin %zacos %zatan
%zsinh %zcosh %ztanh %zasinh %zacosh %zatanh
%nil %pair %list %pair? %lconcat %llength %lfirst %lsecond %lthird
- %lreverse %lempty? %hash %ismall? %string? %f2s
+ %lreverse %lempty? %hash %ismall? %string? %f2s STRINGIMAGE
%ccst %ccstmax %ceq %clt %cle %cgt %cge %c2i %i2c %s2c %c2s %cup %cdown
%sname
%strlength %streq %i2s %schar %strlt %strconc
@@ -418,7 +453,7 @@ $VMsideEffectFreeOperators ==
++ List of simple VM operators
$simpleVMoperators ==
append($VMsideEffectFreeOperators,
- ['SPADCALL,'STRINGIMAGE,'%gensym, '%lreverse!,
+ ['SPADCALL,'%gensym, '%lreverse!,
'%strstc,"MAKE-FULL-CVEC"])
++ Return true if the `form' is semi-simple with respect to
@@ -498,6 +533,8 @@ dependentVars expr == main(expr,nil) where
++ defined in a binding form can be safely replaced by its initalization
++ `expr' in the `body' of the binding form.
canInlineVarDefinition(var,expr,body) ==
+ -- Occasional situation where `expr' evaluates to itself
+ 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
@@ -580,7 +617,7 @@ optBind form ==
[var,expr] := first inits
usedSymbol?(var,rest inits) => ok := false -- no dependency, please.
body := third form
- canInlineVarDefinition(var,expr,body) and isSimpleVMForm expr =>
+ canInlineVarDefinition(var,expr,body) =>
third(form) := substitute!(expr,var,body)
inits := rest inits
ok := false