838862 - BaselineCompiler: Add optimized stub for JSOP_[GET|CALL]PROP on strings.

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Kannan Vijayan [:djvj]]

This is getting hit heavily by both string-fasta, and crypto-sha1 in sunspider.

Comment 1

[Kannan Vijayan [:djvj]]

Attachment: Patch.

Optimizes GETPROPS and CALLPROPS on strings where the property is directly on |String.prototype|.  Cribbed from JM's string getprop IC code.

However, this code uses |nativeLookup| instead of |lookupProperty| since we don't really care to search the proto chain.

Shaves about 25ms (5%) off of SS running BL+Ion.

Comment 2

[Brian Hackett [Laid off!]]

Comment on attachment 711144 [details] [diff] [review]
Patch.

Review of attachment 711144 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/ion/BaselineIC.cpp
@@ +2519,5 @@
> +
> +    bool isFixedSlot = stringProto->isFixedSlot(shape->slot());
> +    uint32_t offset = isFixedSlot
> +                      ? JSObject::getFixedSlotOffset(shape->slot())
> +                      : stringProto->dynamicSlotIndex(shape->slot()) * sizeof(Value);

This logic already appears twice in BaselineIC.cpp, can you common it into some ComputeShapeOffset(shape, bool*, uint32_t*) or similar?

Comment 3

[Kannan Vijayan [:djvj]]

https://hg.mozilla.org/projects/ionmonkey/rev/f27c9d8772ce