713463 - Support JM+TI for architectures without native square root

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Cameron Kaiser [:spectre]]

Attachment: Keep stub calls for arches w/o FPU sqrt

The currently supported architectures all return true for              masm.supportsFloatingPointSqrt() (except, oddly, MacroAssemblerX86.h which returns m_isSSE2Present). However, FastBuiltins does not use this result anyway; even if the function returns false, it still tries to call masm.sqrtDouble(). Besides older G3 and G4 cores that only have a reciprocal square root estimate instead of a true square root instruction like the G5, there are other embedded cores (PPC or otherwise) that may also lack an FPU square root. This patch forces FastBuiltins.cpp to keep the Math.sqrt stub call if there is no FPU square root available.

Comment 1

[Cameron Kaiser [:spectre]]

Thanks for the r+ :)

Comment 2

[Dão Gottwald [:dao]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/c443d73c4346

Comment 3

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

https://hg.mozilla.org/mozilla-central/rev/c443d73c4346