agx: Defeature fsub

All has_fsub does is fuse fsubs (they're unfused otherwise), no point doing that
if we're going to just going to lower.

shader-db is mostly noise.

total instructions in shared programs: 1487217 -> 1487035 (-0.01%)
instructions in affected programs: 22658 -> 22476 (-0.80%)
helped: 85
HURT: 2
helped stats (abs) min: 1.0 max: 12.0 x̄: 2.19 x̃: 1
helped stats (rel) min: 0.38% max: 2.46% x̄: 0.87% x̃: 0.65%
HURT stats (abs)   min: 1.0 max: 3.0 x̄: 2.00 x̃: 2
HURT stats (rel)   min: 0.58% max: 1.08% x̄: 0.83% x̃: 0.83%
95% mean confidence interval for instructions value: -2.51 -1.67
95% mean confidence interval for instructions %-change: -0.97% -0.70%
Instructions are helped.

total bytes in shared programs: 10189996 -> 10189288 (<.01%)
bytes in affected programs: 158132 -> 157424 (-0.45%)
helped: 85
HURT: 2
helped stats (abs) min: 4.0 max: 48.0 x̄: 8.75 x̃: 4
helped stats (rel) min: 0.22% max: 1.44% x̄: 0.51% x̃: 0.38%
HURT stats (abs)   min: 6.0 max: 30.0 x̄: 18.00 x̃: 18
HURT stats (rel)   min: 0.90% max: 0.91% x̄: 0.91% x̃: 0.91%
95% mean confidence interval for bytes value: -9.98 -6.30
95% mean confidence interval for bytes %-change: -0.56% -0.39%
Bytes are helped.

total halfregs in shared programs: 462536 -> 462556 (<.01%)
halfregs in affected programs: 131 -> 151 (15.27%)
helped: 1
HURT: 4
helped stats (abs) min: 2.0 max: 2.0 x̄: 2.00 x̃: 2
helped stats (rel) min: 28.57% max: 28.57% x̄: 28.57% x̃: 28.57%
HURT stats (abs)   min: 4.0 max: 8.0 x̄: 5.50 x̃: 5
HURT stats (rel)   min: 12.77% max: 36.36% x̄: 25.01% x̃: 25.45%
95% mean confidence interval for halfregs value: -0.65 8.65
95% mean confidence interval for halfregs %-change: -18.64% 47.23%
Inconclusive result (value mean confidence interval includes 0).

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22891>

diff --git a/src/asahi/compiler/agx_compile.c b/src/asahi/compiler/agx_compile.c
index 43de92b..3bc3d99 100644 (file)
--- a/src/asahi/compiler/agx_compile.c
+++ b/src/asahi/compiler/agx_compile.c
@@ -1087,8 +1087,6 @@ agx_emit_alu(agx_builder *b, nir_alu_instr *instr)
 
    case nir_op_fsqrt:
       return agx_fmul_to(b, dst, s0, agx_srsqrt(b, s0));
-   case nir_op_fsub:
-      return agx_fadd_to(b, dst, s0, agx_neg(s1));
    case nir_op_fabs:
       return agx_fmov_to(b, dst, agx_abs(s0));
    case nir_op_fneg:

diff --git a/src/asahi/compiler/agx_compile.h b/src/asahi/compiler/agx_compile.h
index b870d5f..dfc4a66 100644 (file)
--- a/src/asahi/compiler/agx_compile.h
+++ b/src/asahi/compiler/agx_compile.h
@@ -200,7 +200,6 @@ static const nir_shader_compiler_options agx_nir_options = {
    .vectorize_io = true,
    .use_interpolated_input_intrinsics = true,
    .lower_rotate = true,
-   .has_fsub = true,
    .has_isub = true,
    .use_scoped_barrier = true,
    .max_unroll_iterations = 32,