RFR: 8179444: AArch64: Put zero_words on a diet

[Andrew Haley]

On 05/05/17 10:47, Andrew Dinn wrote:
> On 03/05/17 18:05, Andrew Haley wrote:
>> New version, corrected:
>> . . .
>> http://cr.openjdk.java.net/~aph/8179444-2/
>>
>> OK?
> 
> The patch looks good (not an official review) except that I don't
> understand one detail. Why does MacroAssembler::zero_words include this?
> 
> +    RuntimeAddress zero_blocks =
> RuntimeAddress(StubRoutines::aarch64::zero_blocks());
> +    assert(zero_blocks.target() != NULL, "zero_blocks stub has not been
> generated");
> +    if (StubRoutines::aarch64::complete()) {
> +      trampoline_call(zero_blocks);
> +    } else {
> +      bl(zero_blocks);
> +    }

Trampoline calls only work from compiler-generated code, so we have to
do something different when we're generating the stubs.  I suppose I
could have had two versions of MacroAssembler::zero_words or added a
parameter to say we're generating stubs.  Would that be clearer?

Andrew.