[Mesa-dev] [PATCH 0/8] i965/vec4: Use Vector-float immediates.

[Matt Turner]

This series adds support to i965's vec4 backend for using vector-float
immediates. The shader-db results are pretty nice:

total instructions in shared programs: 5889529 -> 5876617 (-0.22%)
instructions in affected programs:     465347 -> 452435 (-2.77%)

and there's still room for improvement. It helps 4914 shaders and hurts
none. 50 Valley and Heaven shaders are cut by 30% and there are a few
that do

   mov(8)  g25<1>F  [-1.5F, -1.5F, -0.5F, -1.5F]VF
   mov(8)  g27<1>F  [ 0.5F, -1.5F,  1.5F, -1.5F]VF
   mov(8)  g29<1>F  [-1.5F, -0.5F, -0.5F, -0.5F]VF
   mov(8)  g31<1>F  [ 0.5F, -0.5F,  1.5F, -0.5F]VF
   mov(8)  g33<1>F  [-1.5F,  0.5F, -0.5F,  0.5F]VF
   mov(8)  g35<1>F  [ 0.5F,  0.5F,  1.5F,  0.5F]VF
   mov(8)  g37<1>F  [-1.5F,  1.5F, -0.5F,  1.5F]VF
   mov(8)  g39<1>F  [ 0.5F,  1.5F,  1.5F,  1.5F]VF

before using each register once in a MAD instruction. I'll have to think
more about a general solution that would optimize that into a single

   mov(8)  g25<1>F  [-1.5F,  1.5F, -0.5F,  0.5F]VF

and then sources it 8 times with different swizzles. Probably something
like the constant-combining pass I've floated for the FS backend.

On a side note, can someone tell me how to run Heaven or Valley in an
automated benchmarking mode?