1312395 - Baldr: merge PassTls and InterModule

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect)

Description

[Benjamin Bouvier [:bbouvier] (inactive)]

Attachment: merge-enum.patch

We unveiled a logical invariant in WasmIonCompile with Lars, when looking at the code deciding whether to pass the TLS register: when InterModule is True, then PassTls *must* be true. This indicates we can simplify the code there a bit. Here's the patch doing this and documenting behavior more clearly.

Comment 1

[Luke Wagner [:luke]]

Comment on attachment 8803836 [details] [diff] [review]
merge-enum.patch

Review of attachment 8803836 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/asmjs/WasmIonCompile.cpp
@@ +62,5 @@
> +
> +enum class TlsUsage {
> +    Unused,  // No particular action is taken with respect to the TLS register.
> +    Need,    // The TLS register must be reloaded just before the call.
> +    Preserve // Same, plus the TLS register must be preserved across the call.

I know I suggested "Preserve", but I realized that's not quite right.  I think
  CallerSave // Same, plus space must be allocated to save/restore the TLS register

@@ +65,5 @@
> +    Need,    // The TLS register must be reloaded just before the call.
> +    Preserve // Same, plus the TLS register must be preserved across the call.
> +};
> +
> +bool NeedsTls(TlsUsage usage) {

nit: static and \n before {

Comment 2

[Luke Wagner [:luke]]

Nice cleanup, btw, thanks!

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/00b6c424d440
Merge InterModule/PassTLS into a single enum; r=luke

Comment 4

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/00b6c424d440