444416 - tree branches only have context from immedate parent

Status: RESOLVED FIXED

(Tamarin Graveyard :: Tracing Virtual Machine, defect)

Description

[Edwin Smith]

the code that restores branch tracker & cse tables needs to walk up to the tree root, not just process the first parent.  this should improve the quality of the code on the branch and be a win with -Dtrees enabled.

Comment 1

[Edwin Smith]

Attachment: recover full tracker & cse context

other changes

state.ip is now only updated when exiting back to the interpreter.  dont need to do it on trace.  elimanated ip_starting since GuardRecord now has an absolute ip.

Ignore calldepth when finding merge nodes to use.  this could result in over-using a merge node, but it avoids a terrible bug where we were duplicating merge nodes because calldepth is not computed correctly.  (calldepth needs to be fixed or eradicated).

Comment 2

[Steven Johnson]

Comment on attachment 328738 [details] [diff] [review]
recover full tracker & cse context

did you do a before-and-after run on the performance tests?

Comment 3

[Edwin Smith]

of course:
(with -Dtrees)
                                OLD     NEW
boids                           5016    5016
boidshack                       828     812
gameoflife                      5188    4828
access-binary-trees             78      78
access-fannkuch                 140     125
access-nbody                    156     172
access-nsieve                   47      63
bitops-3bit-bits-in-byte        15      16
bitops-bits-in-byte             31      32
bitops-bitwise-and              187     172
bitops-nsieve-bits              63      47
crypto-md5                      406     422
crypto-sha1                     62      46
math-cordic                     47      47
math-partial-sums               188     203
math-spectral-norm              46      31
s3d-cube                        594     563
s3d-morph                       78      78
s3d-raytrace                    531     344
string-fasta                    125     125
controlflow-recursive           31      16
chess                           73      39
Crypt                           703     672
SOR                             922     938
HeapSort                        8469    8468

Comment 4

[Steven Johnson]

cool, I just saw the "should improve the quality" and wondered if that meant "DID improve the quality..."

Comment 5

[Andreas Gal :gal]

+1 eliminating calldepth

Comment 6

[Andreas Gal :gal]

Comment on attachment 328738 [details] [diff] [review]
recover full tracker & cse context

Looks good. ip instead of ip_adj is a big simplification for us.

Comment 7

[Edwin Smith]

527:50545ad859ea