It should alias to Xchg instead of Swap. Found when testing #16985.
Change-Id: If9fd734a1f89b8b2656f421eb31b9d1b0d95a49f
Reviewed-on: https://go-review.googlesource.com/28512
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Now that we have ops that can return 2 results, have BSF return a result
and flags. We can then get rid of the redundant comparison and use CMOV
instead of CMOVconst ops.
Get rid of a bunch of the ops we don't use. Ctz{8,16}, plus all the Clzs,
and CMOVNEs. I don't think we'll ever use them, and they would be easy
to add back if needed.
Change-Id: I8858a1d017903474ea7e4002fc76a6a86e7bd487
Reviewed-on: https://go-review.googlesource.com/27630
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
One intrinsic was needed to help get the very best
performance out of a future GC; as long as that one was
being added, I also added Bswap since that is sometimes
a handy thing to have. I had intended to fill out the
bit-scan intrinsic family, but the mismatch between the
"scan forward" instruction and "count leading zeroes"
was large enough to cause me to leave it out -- it poses
a dilemma that I'd rather dodge right now.
These intrinsics are not exposed for general use.
That's a separate issue requiring an API proposal change
( https://github.com/golang/proposal )
All intrinsics are tested, both that they are substituted
on the appropriate architecture, and that they produce the
expected result.
Change-Id: I5848037cfd97de4f75bdc33bdd89bba00af4a8ee
Reviewed-on: https://go-review.googlesource.com/20564
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
