The Trunk: Kernel-nice.1048.mcz

Nicolas Cellier uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-nice.1048.mcz

==================== Summary ====================

Name: Kernel-nice.1048
Author: nice
Time: 30 October 2016, 5:18:07.732545 pm
UUID: 476a34de-b988-44ea-8d97-3b553e3e879e
Ancestors: Kernel-nice.1047

Move the duplicated fallback code for timesTwoPower: primitive up in Float.

Adjust the limits a bit,

- we can evaluate down to (1.0 timesTwoPower: -1074) with gradual underflow (Float emin - Float precision + 1).

- we can shift by 29 with SmallInteger, so correctly set the limit to -30 < exponent < 30

=============== Diff against Kernel-nice.1047 ===============

Item was changed:
  ----- Method: BoxedFloat64>>timesTwoPower: (in category 'mathematical functions') -----
  timesTwoPower: anInteger
  "Primitive. Answer with the receiver multiplied by 2.0 raised
  to the power of the argument.
  Optional. See Object documentation whatIsAPrimitive."
 
  <primitive: 54>
+ ^super timesTwoPower: anInteger!
- self isFinite ifFalse: [^self].
- self isZero ifTrue: [^self].
-
- "Make sure that (2.0 raisedTo: Integer) can be safely used without overflow
- For example:
- Float fminNormalized * (2.0 raisedTo: 2000) = Float infinity.
- while:
- (Float fminNormalized timesTwoPower: 2000) = (2.0 raisedTo: 2000+Float emin)."
- anInteger > Float emax ifTrue: [^(self timesTwoPower: Float emax) timesTwoPower: anInteger - Float emax].
-
- "In case of gradual underflow, timesTwoPower: is not exact, so greatest care must be taken
- because two consecutive timesTwoPower: might differ from a single one"
- anInteger < Float emin
- ifTrue:
- [| deltaToUnderflow |
- deltaToUnderflow := Float emin - self exponent max: Float emin.
- deltaToUnderflow >= 0 ifTrue:
- ["self is already near or past underflow, so don't care, result will be zero"
- deltaToUnderflow := Float emin].
- ^(self timesTwoPower: deltaToUnderflow) timesTwoPower: anInteger - deltaToUnderflow].
-
- "If (2.0 raisedToInteger: anInteger) fit in a positive SmallInteger, then use faster SmallInteger conversion.
- Note that SmallInteger maxVal highBit = 30 in a 32 bits image, so 1 can be shifted 29 times."
- anInteger > -29 ifTrue: [
- anInteger < 0 ifTrue: [^ self / (1 bitShift: (0 - anInteger)) asFloat].
- anInteger < 30 ifTrue: [^ self * (1 bitShift: anInteger) asFloat]].
-
- ^ self * (2.0 raisedToInteger: anInteger)!

Item was added:
+ ----- Method: Float>>timesTwoPower: (in category 'mathematical functions') -----
+ timesTwoPower: anInteger
+ "Answer with the receiver multiplied by 2.0 raised
+ to the power of the argument"
+
+ self isFinite ifFalse: [^self].
+ self isZero ifTrue: [^self].
+
+ "Make sure that (2.0 raisedTo: Integer) can be safely used without overflow
+ For example:
+ Float fminNormalized * (2.0 raisedTo: 2000) = Float infinity.
+ while:
+ (Float fminNormalized timesTwoPower: 2000) = (2.0 raisedTo: 2000+Float emin)."
+ anInteger > Float emax ifTrue: [^(self timesTwoPower: Float emax) timesTwoPower: anInteger - Float emax].
+
+ "In case of gradual underflow, timesTwoPower: is not exact, so greatest care must be taken
+ because two consecutive timesTwoPower: might differ from a single one"
+ anInteger < (Float emin - Float precision + 1)
+ ifTrue:
+ [| deltaToUnderflow |
+ deltaToUnderflow := Float emin - self exponent max: Float emin - Float precision + 1.
+ deltaToUnderflow >= 0 ifTrue:
+ ["self is already near or past underflow, so don't care, result will be zero"
+ deltaToUnderflow := Float emin].
+ ^(self timesTwoPower: deltaToUnderflow) timesTwoPower: anInteger - deltaToUnderflow].
+
+ "If (2.0 raisedToInteger: anInteger) fit in a positive SmallInteger, then use faster SmallInteger conversion.
+ Note that SmallInteger maxVal highBit = 30 in a 32 bits image, so 1 can be shifted 29 times."
+ anInteger > -30 ifTrue: [
+ anInteger < 0 ifTrue: [^ self / (1 bitShift: 0 - anInteger) asFloat].
+ anInteger < 30 ifTrue: [^ self * (1 bitShift: anInteger) asFloat]].
+
+ ^ self * (2.0 raisedToInteger: anInteger)!

Item was changed:
  ----- Method: SmallFloat64>>timesTwoPower: (in category 'mathematical functions') -----
  timesTwoPower: anInteger
  "Primitive. Answer with the receiver multiplied by 2.0 raised
  to the power of the argument.
  Optional. See Object documentation whatIsAPrimitive."
 
  <primitive: 554>
+ ^super timesTwoPower: anInteger!
- self isFinite ifFalse: [^self].
- self isZero ifTrue: [^self].
-
- "Make sure that (2.0 raisedTo: Integer) can be safely used without overflow
- For example:
- Float fminNormalized * (2.0 raisedTo: 2000) = Float infinity.
- while:
- (Float fminNormalized timesTwoPower: 2000) = (2.0 raisedTo: 2000+Float emin)."
- anInteger > Float emax ifTrue: [^(self timesTwoPower: Float emax) timesTwoPower: anInteger - Float emax].
-
- "In case of gradual underflow, timesTwoPower: is not exact, so greatest care must be taken
- because two consecutive timesTwoPower: might differ from a single one"
- anInteger < Float emin
- ifTrue:
- [| deltaToUnderflow |
- deltaToUnderflow := Float emin - self exponent max: Float emin.
- deltaToUnderflow >= 0 ifTrue:
- ["self is already near or past underflow, so don't care, result will be zero"
- deltaToUnderflow := Float emin].
- ^(self timesTwoPower: deltaToUnderflow) timesTwoPower: anInteger - deltaToUnderflow].
-
- "If (2.0 raisedToInteger: anInteger) fit in a positive SmallInteger, then use faster SmallInteger conversion.
- Note that SmallInteger maxVal highBit = 30 in a 32 bits image, so 1 can be shifted 29 times."
- anInteger > -29 ifTrue: [
- anInteger < 0 ifTrue: [^ self / (1 bitShift: (0 - anInteger)) asFloat].
- anInteger < 30 ifTrue: [^ self * (1 bitShift: anInteger) asFloat]].
-
- ^ self * (2.0 raisedToInteger: anInteger)!