1282411 - Make ARM simulator enable SDIV and UDIV by default

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect)

Description

[Lars T Hansen [:lth]]

Currently the simulator enables many modern features (VFPv3, VFPv4, and NEON) but not integer division (SDIV and UDIV).  In practice, most new ARM chips on mobile platforms will have those instructions, and we should enable them for better test coverage.

From a practical point of view, this means that simulator runs without ARMHWCAP=... will have as a default the set armv7,vfp,vfpv3,vfpv4,neon,idiva: the last flag is new.

Comment 1

[Lars T Hansen [:lth]]

Attachment: bug1282411-divide-and-conquer.patch

Comment 2

[Jan de Mooij [:jandem]]

Comment on attachment 8765462 [details] [diff] [review]
bug1282411-divide-and-conquer.patch

Review of attachment 8765462 [details] [diff] [review]:
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Do the fuzzers still have ways to disable this, using the shell function or something?

Comment 3

[Lars T Hansen [:lth]]

(In reply to Jan de Mooij [:jandem] from comment #2)
> 
> Do the fuzzers still have ways to disable this, using the shell function or
> something?

Unless I'm misreading our code, if ARMHWCAP is present at all it must define all flags it wants to set, not flags it wants in addition to a default.  So yes, fuzzers should be OK with this.

Comment 4

[Lars T Hansen [:lth]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/a8fdc81e834ebdee12534b71dc4384b4c278bb50
Bug 1282411 - Enable SDIV and UDIV by default on ARM simulator. r=jandem

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/a8fdc81e834e