The Trunk: Collections-eem.746.mcz
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Eliot Miranda uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-eem.746.mcz ==================== Summary ==================== Name: Collections-eem.746 Author: eem Time: 18 April 2017, 2:10:45.148995 pm UUID: 8d9adaca-1401-4323-974f-1aed16ae3688 Ancestors: Collections-eem.745 Nuke the pointless override of ByteSString class>>stringHash:initialHash: in ByteSymbol class. Rewrite the non-byte version to use the hashMultiply primitive. =============== Diff against Collections-eem.745 =============== Item was removed: - ----- Method: ByteSymbol class>>stringHash:initialHash: (in category 'primitives') ----- - stringHash: aString initialHash: speciesHash - ^ByteString stringHash: aString initialHash: speciesHash! Item was changed: ----- Method: String class>>stringHash:initialHash: (in category 'primitives') ----- stringHash: aString initialHash: speciesHash + "Answer the hash of a byte-indexed string, using speciesHash as the initial value. + See SmallInteger>>hashMultiply." + | hash | - - | stringSize hash low | - stringSize := aString size. hash := speciesHash bitAnd: 16r0FFFFFFF. + 1 to: aString size do: + [:pos | + hash := (hash + (aString basicAt: pos)) hashMultiply]. + ^hash! - 1 to: stringSize do: [ :pos | - hash := hash + (aString basicAt: pos). - "Begin hashMultiply" - low := hash bitAnd: 16383. - hash := (16r260D * low + ((16r260D * (hash // 16384) + (16r0065 * low) bitAnd: 16383) * 16384)) bitAnd: 16r0FFFFFFF ]. - ^hash. - - - ! |
Re: The Trunk: Collections-eem.746.mcz
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On Tue, 18 Apr 2017, [hidden email] wrote:
> Eliot Miranda uploaded a new version of Collections to project The Trunk: > http://source.squeak.org/trunk/Collections-eem.746.mcz > > ==================== Summary ==================== > > Name: Collections-eem.746 > Author: eem > Time: 18 April 2017, 2:10:45.148995 pm > UUID: 8d9adaca-1401-4323-974f-1aed16ae3688 > Ancestors: Collections-eem.745 > > Nuke the pointless override of ByteSString class>>stringHash:initialHash: in ByteSymbol class. Rewrite the non-byte version to use the hashMultiply primitive. Do you mean that the Smalltalk code is as quick as the primitive? Because without the VM changes, the primitive is 3-4 times quicker than hash := speciesHash bitAnd: 16rFFFFFFF. 1 to: aString size do: [:pos | hash := hash + (aString basicAt: pos) * 1664525 bitAnd: 16rFFFFFFF ]. ^ hash So, I presume such loop will still be slower even with the primitive for #hashMultiply. Levente > > =============== Diff against Collections-eem.745 =============== > > Item was removed: > - ----- Method: ByteSymbol class>>stringHash:initialHash: (in category 'primitives') ----- > - stringHash: aString initialHash: speciesHash > - ^ByteString stringHash: aString initialHash: speciesHash! > > Item was changed: > ----- Method: String class>>stringHash:initialHash: (in category 'primitives') ----- > stringHash: aString initialHash: speciesHash > + "Answer the hash of a byte-indexed string, using speciesHash as the initial value. > + See SmallInteger>>hashMultiply." > + | hash | > - > - | stringSize hash low | > - stringSize := aString size. > hash := speciesHash bitAnd: 16r0FFFFFFF. > + 1 to: aString size do: > + [:pos | > + hash := (hash + (aString basicAt: pos)) hashMultiply]. > + ^hash! > - 1 to: stringSize do: [ :pos | > - hash := hash + (aString basicAt: pos). > - "Begin hashMultiply" > - low := hash bitAnd: 16383. > - hash := (16r260D * low + ((16r260D * (hash // 16384) + (16r0065 * low) bitAnd: 16383) * 16384)) bitAnd: 16r0FFFFFFF ]. > - ^hash. > - > - > - ! |
Re: The Trunk: Collections-eem.746.mcz
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Hi Levente,
On Tue, Apr 18, 2017 at 3:13 PM, Levente Uzonyi <[hidden email]> wrote: On Tue, 18 Apr 2017, [hidden email] wrote: No. I mean that the non-primitive version for WideString should use the hashMultiply primitive, not the decomposed non-primitive hashMultiply. Because without the VM changes, the primitive is 3-4 times quicker than That's right. But hash := (hash + (aString basicAt: pos)) hashMultiply is much faster than hash := hash + (aString basicAt: pos). "Begin hashMultiply" low := hash bitAnd: 16383. hash := (16r260D * low + ((16r260D * (hash bitShift: -14) + (16r0065 * low) bitAnd: 16383) * 16384)) bitAnd: 16r0FFFFFFF. in the latest VMs which have a machine code primitive for hashMultiply. Im the measurements I posted yesterday they're twice as fast.
_,,,^..^,,,_ best, Eliot |
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