[Mesa-dev] [PATCH] i965/hsw: Initialize SLM index in state register

[Jordan Justen]

On 2016-03-04 16:07:08, Matt Turner wrote:
> Alternatively, if overwriting FFTID is bad, instead of emitting
> 
>    shr(1)  sr0.1:UD  g0.0:UD  16UD
> 
> you could write only the low word:
> 
>    mov(1)  sr0.2:UW  g0.1:UW
> 
> or maybe use an AND to ensure you're writing zeros to the MBZ bits of
> the status register.

Ok, with Matt's suggestion, it is pretty easy to remove the FFTID
concern. I made this change:

-      abld.SHR(suboffset(brw_sr0_reg(), 1), g0, brw_imm_d(16));
+      abld.MOV(retype(suboffset(brw_sr0_reg(), 1), BRW_REGISTER_TYPE_UW),
+               suboffset(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UW), 1));

Which produces:

mov(1)          sr0.2<1>UW      g0.1<0,1,0>UW                   { align1 WE_all };

And, therefore shouldn't touch the FFTID bits in the upper 16-bits of
sr0.1.

Matt, Ken: Does that look okay?

-Jordan