Closed Bug 779361 Opened 10 years ago Closed 10 years ago

IonMonkey: Reuse input in LAbsD and LSqrtD.

Categories

(Core :: JavaScript Engine, defect)

All
Linux
defect
Not set
normal

Tracking

()

RESOLVED FIXED

People

(Reporter: sstangl, Unassigned)

Details

(Whiteboard: [ion:t])

Attachments

(1 file)

Attached patch patchSplinter Review
LAbsD and LSqrtD can trivially reuse the input register.
Attachment #647770 - Flags: review?(nicolas.b.pierron)
Attachment #647770 - Flags: review?(nicolas.b.pierron) → review+
http://hg.mozilla.org/projects/ionmonkey/rev/f35b90ed0b8d
Status: NEW → RESOLVED
Closed: 10 years ago
Resolution: --- → FIXED
This constrains regalloc a bit though, if you have

var y = sqrt(x);
var z = abs(x);
// ..no other uses of x..

Regalloc could do

x in r0
sqrt: r0 -> r1
abs : r0 -> r0

Now it has to use an explicit move:

x in r0
move: r0 -> r1
sqrt: r1 -> r1
abs : r0 -> r0

I thought defineReuseInput was only used in cases where the hardware requires it (most non-FP instructions on x86).
So the useAtStart is good, but not the defineReuseInput ?
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