Fixes ARM multiplication instruction version checking.

Fixes ARM instruction version checking.

Emulates umaal on ARMv5TE.

Committed: https://code.google.com/p/dart/source/detail?r=44940

[zra, 2015-04-07 15:00:19]

zra@google.com changed reviewers:
+ regis@google.com

[regis, 2015-04-07 16:24:37]

LGTMwC

https://codereview.chromium.org/1062593003/diff/40001/runtime/vm/assembler_ar...
File runtime/vm/assembler_arm.cc (right):

https://codereview.chromium.org/1062593003/diff/40001/runtime/vm/assembler_ar...
runtime/vm/assembler_arm.cc:457: } else {
You should assert that none of the registers are IP.

https://codereview.chromium.org/1062593003/diff/40001/runtime/vm/assembler_ar...
runtime/vm/assembler_arm.cc:460: adds(rd_lo, rd_lo, Operand(rd_hi), cond);
You cannot set the flags and expect the next instruction to still work with the
original cond. I think you could assert that cond is AL if we emulate umaal.

[zra, 2015-04-07 17:34:43]

https://codereview.chromium.org/1062593003/diff/40001/runtime/vm/assembler_ar...
File runtime/vm/assembler_arm.cc (right):

https://codereview.chromium.org/1062593003/diff/40001/runtime/vm/assembler_ar...
runtime/vm/assembler_arm.cc:457: } else {
On 2015/04/07 16:24:37, regis wrote:
> You should assert that none of the registers are IP.

Done.

https://codereview.chromium.org/1062593003/diff/40001/runtime/vm/assembler_ar...
runtime/vm/assembler_arm.cc:460: adds(rd_lo, rd_lo, Operand(rd_hi), cond);
On 2015/04/07 16:24:37, regis wrote:
> You cannot set the flags and expect the next instruction to still work with
the
> original cond. I think you could assert that cond is AL if we emulate umaal.

Whoops. Since we aren't using umaal conditionally anywhere, I'd prefer to remove
the condition argument. I think that will make it harder to break compatibility
with ARMv5TE.

[zra, 2015-04-07 17:36:56]

Committed patchset #4 (id:60001) manually as r44940 (presubmit successful).