* interp/g-opt.boot ($VMsideEffectFreeOperators): Include %fdecode.

	* interp/lisp-backend.boot: Expand it.
	* algebra/sf.spad.pamphlet (DoubleFloat): Remove %fmanexpr import.
	Use %fdecode to access Lisp-level double-float decoding.
	[mantissa]: Rewrite.
	[exponent]: Likewise.
	[negative?]: Likewise.
	[positive?]: Likewise.
	[manexp]: Likewise.
	* algebra/view2D.spad.pamphlet (TwoDimensionalViewport): Tidy.

5 files changed, 35 insertions, 19 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f2422129..10413a15 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,18 @@
 2011-10-23  Gabriel Dos Reis  <gdr@cs.tamu.edu>
 
+	* interp/g-opt.boot ($VMsideEffectFreeOperators): Include %fdecode.
+	* interp/lisp-backend.boot: Expand it.
+	* algebra/sf.spad.pamphlet (DoubleFloat): Remove %fmanexpr import.
+	Use %fdecode to access Lisp-level double-float decoding.
+	[mantissa]: Rewrite.
+	[exponent]: Likewise.
+	[negative?]: Likewise.
+	[positive?]: Likewise.
+	[manexp]: Likewise.
+	* algebra/view2D.spad.pamphlet (TwoDimensionalViewport): Tidy.
+
+2011-10-23  Gabriel Dos Reis  <gdr@cs.tamu.edu>
+
 	* interp/compiler.boot (compForm2): Simplify. Don't bother with
 	subsumption.  Exit early on empty modemap candidate list.
 
diff --git a/src/algebra/sf.spad.pamphlet b/src/algebra/sf.spad.pamphlet
index e15fdddd..fc01b769 100644
--- a/src/algebra/sf.spad.pamphlet
+++ b/src/algebra/sf.spad.pamphlet
@@ -286,7 +286,6 @@ DoubleFloat(): Join(FloatingPointSystem, DifferentialRing,
    import %fmaxval: () -> %             from Foreign Builtin
    import %fbase: () -> PositiveInteger from Foreign Builtin
    import %fprec: () -> PositiveInteger from Foreign Builtin
-   import %fmanexp: % -> Record(man: %,exp: Integer) from Foreign Builtin
    import %i2f: Integer -> %            from Foreign Builtin
    import %fabs: % -> %                 from Foreign Builtin
    import %fneg: % -> %                 from Foreign Builtin
@@ -327,12 +326,16 @@ DoubleFloat(): Join(FloatingPointSystem, DifferentialRing,
    import %fatanh: % -> %               from Foreign Builtin
    import %fcstpi: () -> %              from Foreign Builtin
    import %fNaN?: % -> Boolean          from Foreign Builtin
-
-   manexp: % -> MER
+   import %fdecode: % -> List Integer   from Foreign Builtin
+   import %lfirst: List Integer -> Integer from Foreign Builtin
+   import %lsecond: List Integer -> Integer from Foreign Builtin
+   import %lthird: List Integer -> Integer from Foreign Builtin
 
    base()           == %fbase()
-   mantissa x       == manexp(x).MANTISSA
-   exponent x       == manexp(x).EXPONENT
+   mantissa x       ==
+     fp := %fdecode x
+     %lfirst fp * %lthird fp
+   exponent x       == %lsecond %fdecode x
    precision()      == %fprec()
    bits()           ==
      base() = 2 => precision()
@@ -394,7 +397,7 @@ DoubleFloat(): Join(FloatingPointSystem, DifferentialRing,
    acoth x          == atanh(1/x)
    asech x          == acosh(1/x)
    x:% / y:%        == %fdiv(x,y)
-   negative? x      == x < 0
+   negative? x      == sign x < 0
    zero? x          == x = 0
    one? x           == x = 1
    hash x           == %hash x
@@ -438,18 +441,14 @@ DoubleFloat(): Join(FloatingPointSystem, DifferentialRing,
      x = (%i2f(n := wholePart x)) => n
      "failed"
 
-   sign(x) == retract FLOAT_-SIGN(x,1)$Lisp
+   sign(x) == %lthird %fdecode x
    abs x   == %fabs x
-   positive? x == 0 < x
-   manexp(x) ==
-      zero? x => [0,0]
-      s := sign x
-      x := abs x
-      if x > max()$% then
-        return [s*mantissa(max())+1,exponent max()]
-      me: Record(man: %,exp: Integer) := %fmanexp x
-      two53 := base()**precision()
-      [s*wholePart(two53 * me.man ),me.exp-precision()]
+   positive? x == sign x > 0
+   manexp(x: %): MER ==
+      fp := %fdecode x
+      m := %lfirst fp
+      zero? m => [m,0]
+      [%lfirst fp * %lthird fp, %lsecond fp]
 
 -- rationalApproximation(y,d,b) ==
 --    this is the quotient remainder algorithm (requires wholePart operation)
diff --git a/src/algebra/view2D.spad.pamphlet b/src/algebra/view2D.spad.pamphlet
index 5a032a44..bdd63f5e 100644
--- a/src/algebra/view2D.spad.pamphlet
+++ b/src/algebra/view2D.spad.pamphlet
@@ -779,7 +779,7 @@ TwoDimensionalViewport ():Exports == Implementation where
         -- the viewports in its list. a -1 means it doesn't
         -- exist.
       sendI(VIEW,viewport.key)$Lisp
-      i := getI(VIEW)$Lisp
+      i: Integer := getI(VIEW)$Lisp
       negative? i => 
         viewport.key := 0$I
         error "This viewport has already been closed!"
diff --git a/src/interp/g-opt.boot b/src/interp/g-opt.boot
index e2a1e7c9..f044b7a2 100644
--- a/src/interp/g-opt.boot
+++ b/src/interp/g-opt.boot
@@ -431,7 +431,7 @@ $VMsideEffectFreeOperators ==
     %idec %irem %iquo %idivide %idec %irandom
     %feq %flt %fle %fgt %fge %fmul %fadd %fsub %fexp %fmin %fmax %float?
     %fpowi %fdiv %fneg %i2f %fminval %fmaxval %fbase %fprec %ftrunc
-    %fsqrt %fpowf %flog %flog2 %flog10 %fmanexp %fNaN?
+    %fsqrt %fpowf %flog %flog2 %flog10 %fmanexp %fNaN? %fdecode
     %fsin  %fcos  %ftan  %fcot  
     %fasin %facos %fatan %facot 
     %fsinh  %fcosh  %ftanh 
diff --git a/src/interp/lisp-backend.boot b/src/interp/lisp-backend.boot
index 89972184..17efec64 100644
--- a/src/interp/lisp-backend.boot
+++ b/src/interp/lisp-backend.boot
@@ -322,6 +322,9 @@ expandFatanh ['%fatanh,x] ==
 expandFacoth ['%facoth,x] ==
   ['C_-TO_-R,['ACOTH,expandToVMForm x]]
 
+expandFdecode ['%fdecode,x] ==
+  ['MULTIPLE_-VALUE_-CALL,['FUNCTION,'LIST],
+    ['INTEGER_-DECODE_-FLOAT,expandToVMForm x]]
 
 -- String operations
 
@@ -655,6 +658,7 @@ for x in [
    ['%idivide, :function expandIdivide],
 
    ['%i2f,     :function expandI2f],
+   ['%fdecode, :function expandFdecode],
    ['%fbase,   :function expandFbase],
    ['%feq,     :function expandFeq],
    ['%fgt,     :function expandFgt],