RFR: 8046943: RSA Acceleration

[David M. Lloyd]

On 06/29/2015 04:32 AM, Andrew Haley wrote:
> On 29/06/15 09:37, Vladimir Kozlov wrote:
>> Hi, Andrew
>>
>> Did you file RFE for this change?  8046943 is JEP.
>
> No; I will do so.
>
>> typo? "less" -> "more".
>>
>> +     * number of ints in the number is less than this value we do not
>> +     * use the intrinsic.
>> +     */
>> +    private static final int MONTGOMERY_INTRINSIC_THRESHOLD = 512;
>>
>> trailing spaces:
>> src/java.base/share/classes/java/math/BigInteger.java:273: Trailing whitespace
>> src/java.base/share/classes/java/math/BigInteger.java:2770: Trailing whitespace
>>
>> I ran changes through JPRT and linux/solaris passed - thanks.
>> Next step - Windows:
>>
>> C:\jprt\T\P1\s\hotspot\src\cpu\x86\vm\sharedRuntime_x86_64.cpp(26) : fatal error C1083: Cannot open include file:
>> 'alloca.h': No such file or directory
>
> Hmm, okay.  This is going to be fun.  :-)
>
> AFAIK OpenJDK builds with Visual Studio.  The VS equivalent of
> alloca() is called _alloca() and its header file is <malloc.h>.  I'm
> going to try to do this untested.  I think that autoconf will #include
> malloc.h on Windows automagically, so all that I have to do is create
> a #define for alloca() on Windows.

Out of curiosity, instead of e.g.:

   unsigned long *scratch = (unsigned long *)alloca(total_allocation);

Could you not just use e.g.:

   unsigned long scratch[longwords * 4];

and avoid alloca altogether?

-- 
- DML