[PATCH] D21189: Create subranges for new intervals resulting from live interval splitting

[Quentin Colombet via llvm-commits]

> On Jun 9, 2016, at 2:50 PM, Krzysztof Parzyszek <kparzysz at codeaurora.org> wrote:
> 
> kparzysz marked an inline comment as done.
> 
> ================
> Comment at: lib/CodeGen/VirtRegMap.cpp:339
> @@ -338,2 +338,3 @@
>          "Reads of completely dead register should be marked undef already");
> +  assert(LI.hasSubRanges());
>   unsigned SubRegIdx = MO.getSubReg();
> ----------------
> qcolombet wrote:
>> I believe the assertion should be on SubRegIdx != 0, because hasSubRanges is only populated when we have sub register liveness enabled.
> This function is only called when the subregister liveness is enabled, and when MO has a non-zero subregister (line 399 below).

Oh that’s right, I missed the NoSubRegLivess check in the caller.
That being said, given that we know both hasSubRange and SubRegIdx are non-zero, it wouldn’t hurt to check both :).

> 
> 
> Repository:
>  rL LLVM
> 
> http://reviews.llvm.org/D21189
> 
> 
>