RFR (M): 6443505: Ideal() function for CmpLTMask

[David Chase]

On 2013-04-08, at 1:52 PM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
> src/cpu/x86/vm/x86_32.ad:
> 
> !   format %{ "XOR    ECX,ECX\t# cadd_LTMaskA\n\t"
> +   format %{ "XORL     $tmp, $tmp\t# and_cmpLTMaskA\n\t"
> 
> Sometimes you have cmpLT and sometimes not.  Always use the instruct name.

So cmpLTMask everywhere?  And use a name that IDs the pattern, right?

> + instruct and_cmpLTMaskB(rRegI p, rRegI q, rRegI y, eFlagsReg cr)
> + %{
> 
> Could you move the %{ to the same line to be like the existing ones (I know that 32 and 64 are different; it's annoying):
> 
> + instruct cadd_cmpLTMaskB(rRegI p, rRegI q, rRegI y, eFlagsReg cr) %{


> src/cpu/x86/vm/x86_64.ad:
> 
> + /* Better to save a register than avoid a branch
> 
> Do we really want to keep the unused code?

We could lose it.  I think we need to keep a comment to document why we did it with a branch.

David