code review 104770047: armasm: add VFP, golden testdata

armasm: add VFP, golden testdata

Add VFP instructions, which completes what is
used by the Go arm toolchain.

Also add tests comparing against testdata.
To generate testdata, same as on x86:
run exhaustive tests and save the ones
that increase the code or table coverage.

[rsc, 2014-06-01 03:03:25]

Hello minux,

I'd like you to review this change to
https://code.google.com/p/rsc.arm/

[minux, 2014-06-01 09:15:07]

LGTM.

Now I see why ARM instruction decoding is hard when VFP instructions
are involved.

https://codereview.appspot.com/104770047/diff/40001/arm.csv
File arm.csv (right):

https://codereview.appspot.com/104770047/diff/40001/arm.csv#newcode299
arm.csv:299: "0x0fbf0ed0","0x0eb00ac0","VABS<c>.F<32,64> <Sd,Dd>,
<Sm,Dm>","cond:4|1|1|1|0|1|D|1|1|0|0|0|0|Vd:4|1|0|1|sz|1|1|M|0|Vm:4","vfp"
is this change generated automatically or a manual edit?
if it's the latter, should we add note somewhere so that when
we update this file to a future arm architecture version, we
have a memo what manual changes should we apply?

https://codereview.appspot.com/104770047/diff/40001/arm.csv#newcode453
arm.csv:453:
"0xffffffff","0xf7fabcfd","UNDEF","1|1|1|1|0|1|1|1|1|1|1|1|1|0|1|0|1|0|1|1|1|1|0|0|1|1|1|1|1|1|0|1",""
is this entry exist only for the undef instruction used by liblink?

https://codereview.appspot.com/104770047/diff/40001/armmap/map.go
File armmap/map.go (right):

https://codereview.appspot.com/104770047/diff/40001/armmap/map.go#newcode138
armmap/map.go:138: // For now, ignore the VFP floating point instructions.
update the comment please.

[rsc, 2014-06-01 17:40:28]

Actually, now that I actually know the details, VFP seems relatively easy. It's
the Advanced SIMD instructions (the other V instructions) that are the complex
ones.

https://codereview.appspot.com/104770047/diff/40001/arm.csv
File arm.csv (right):

https://codereview.appspot.com/104770047/diff/40001/arm.csv#newcode299
arm.csv:299: "0x0fbf0ed0","0x0eb00ac0","VABS<c>.F<32,64> <Sd,Dd>,
<Sm,Dm>","cond:4|1|1|1|0|1|D|1|1|0|0|0|0|Vd:4|1|0|1|sz|1|1|M|0|Vm:4","vfp"
On 2014/06/01 09:15:06, minux wrote:
> is this change generated automatically or a manual edit?
> if it's the latter, should we add note somewhere so that when
> we update this file to a future arm architecture version, we
> have a memo what manual changes should we apply?

All the changes have been done by hand, although some were global search and
replace. The idea is that before we try to update to the next version we get the
pdf reader generating this arm.csv for the current version.

https://codereview.appspot.com/104770047/diff/40001/arm.csv#newcode453
arm.csv:453:
"0xffffffff","0xf7fabcfd","UNDEF","1|1|1|1|0|1|1|1|1|1|1|1|1|0|1|0|1|0|1|1|1|1|0|0|1|1|1|1|1|1|0|1",""
On 2014/06/01 09:15:06, minux wrote:
> is this entry exist only for the undef instruction used by liblink?

Yes.

https://codereview.appspot.com/104770047/diff/40001/armmap/map.go
File armmap/map.go (right):

https://codereview.appspot.com/104770047/diff/40001/armmap/map.go#newcode138
armmap/map.go:138: // For now, ignore the VFP floating point instructions.
On 2014/06/01 09:15:06, minux wrote:
> update the comment please.

Done.

[rsc, 2014-06-01 17:57:30]

*** Submitted as
https://code.google.com/p/rsc/source/detail?r=616aea947362&repo=arm ***

armasm: add VFP, golden testdata

Add VFP instructions, which completes what is
used by the Go arm toolchain.

Also add tests comparing against testdata.
To generate testdata, same as on x86:
run exhaustive tests and save the ones
that increase the code or table coverage.

LGTM=minux
R=minux
https://codereview.appspot.com/104770047