683187 - OP_applytype must not launder its result type

Status: RESOLVED WONTFIX

(Tamarin Graveyard :: Virtual Machine, defect, P3)

Description

[Lars T Hansen]

At present, the verifier computes the type NULL for OP_applytype, but much more is frequently known about the type, and by making that information available we allow operations that use the value computed by OP_applytype (such as OP_construct) to be specialized at compile time.  In turn, the type of the value returned from the OP_construct will also be known.

The cumulative effect is to speed up the evaluation of expressions such as vector initializers and operations on them.

Comment 1

[Lars T Hansen]

Attachment: Infer the types for OP_applytype

Infer the result type of OP_applytype, under static versioning.

This patch by itself - no changes to the code generator - yields good speedups on the benchmarks attached to bug #532690, speeding vector-init-1 from 282 to 338 it/sec (speedup=1.20) and vector-init-2 from 361 to 424 it/sec (speedup=1.17).  Measurements were taken with various other pending optimization applied (notably inlining of vector writes, bug #599099).

I guess the main question about this patch is whether the handling and creation of traits in the Vector.<C> case - non-primitive types - is correct, and if not, whether it can be made correct by adding guards that will succeed often in practice.

Comment 2

[Edwin Smith]

Verifier.cpp:1802: ... is factoring desireable?

yup, desireable.  

maybe add an api in DomainMgr that takes param_ctraits and returns
the possibly cached, created-on-demand new vector ctraits?  The explicit
string wrangling makes me nervous but given no other api, there's nothing
obviously wrong about it.  weird for surface syntax to show up here, ya know?

Comment 3

[Sylvestre Ledru [:Sylvestre]]

No assignee, updating the status.

Comment 4

[Sylvestre Ledru [:Sylvestre]]

No assignee, updating the status.

Comment 5

[Sylvestre Ledru [:Sylvestre]]

No assignee, updating the status.

Comment 6

[Sylvestre Ledru [:Sylvestre]]

Tamarin is a dead project now. Mass WONTFIX.

Comment 7

[Sylvestre Ledru [:Sylvestre]]

Tamarin isn't maintained anymore. WONTFIX remaining bugs.