When ffma is available, we can use a different arrangement of
constants to
get a better result. On freedreno/ir3, this reduces the YUV->RGB to 7
scalar ffma. On freedreno/a2xx, it will allow YUV->RGB to be 3 vec4
ffma.
Signed-off-by: Jonathan Marek <jonat...@marek.ca>
---
src/compiler/nir/nir_lower_tex.c | 62
++++++++++++++++++++++----------
1 file changed, 43 insertions(+), 19 deletions(-)
diff --git a/src/compiler/nir/nir_lower_tex.c
b/src/compiler/nir/nir_lower_tex.c
index 6a6b6c41a7..f7c821bb34 100644
--- a/src/compiler/nir/nir_lower_tex.c
+++ b/src/compiler/nir/nir_lower_tex.c
@@ -342,25 +342,49 @@ convert_yuv_to_rgb(nir_builder *b,
nir_tex_instr *tex,
nir_ssa_def *y, nir_ssa_def *u, nir_ssa_def *v,
nir_ssa_def *a)
{
- nir_const_value m[3] = {
- { .f32 = { 1.0f, 0.0f, 1.59602678f, 0.0f } },
- { .f32 = { 1.0f, -0.39176229f, -0.81296764f, 0.0f } },
- { .f32 = { 1.0f, 2.01723214f, 0.0f, 0.0f } }
- };
-
- nir_ssa_def *yuv =
- nir_vec4(b,
- nir_fmul(b, nir_imm_float(b, 1.16438356f),
- nir_fadd(b, y, nir_imm_float(b, -16.0f /
255.0f))),
- nir_channel(b, nir_fadd(b, u, nir_imm_float(b,
-128.0f / 255.0f)), 0),
- nir_channel(b, nir_fadd(b, v, nir_imm_float(b,
-128.0f / 255.0f)), 0),
- nir_imm_float(b, 0.0));
-
- nir_ssa_def *red = nir_fdot4(b, yuv, nir_build_imm(b, 4, 32,
m[0]));
- nir_ssa_def *green = nir_fdot4(b, yuv, nir_build_imm(b, 4, 32,
m[1]));
- nir_ssa_def *blue = nir_fdot4(b, yuv, nir_build_imm(b, 4, 32,
m[2]));
-
- nir_ssa_def *result = nir_vec4(b, red, green, blue, a);
+ nir_ssa_def *result;
+
+
+ if (b->shader->options->fuse_ffma) {
+ nir_const_value m[4] = {
+ { .f32 = { 1.16438356f, 1.16438356f, 1.16438356f, 0.0f } },
+ { .f32 = { 0.0f, -0.39176229f, 2.01723214f, 0.0f } },
+ { .f32 = { 1.59602678f,-0.81296764f, 0.0f, 0.0f } },
+ };
+ static const float y_off = -16.0f * 1.16438356f / 255.0f;
+ static const float sc = 128.0f / 255.0f;
+
+ nir_ssa_def *offset =
+ nir_vec4(b,
+ nir_imm_float(b, y_off - sc * 1.59602678f),
+ nir_imm_float(b, y_off + sc * (0.81296764f +
0.39176229f)),
+ nir_imm_float(b, y_off - sc * 2.01723214f),
+ a);
+
+ result = nir_ffma(b, y, nir_build_imm(b, 4, 32, m[0]),
+ nir_ffma(b, u, nir_build_imm(b, 4, 32, m[1]),
+ nir_ffma(b, v, nir_build_imm(b, 4,
32, m[2]), offset)));
+ } else {
+ nir_const_value m[3] = {
+ { .f32 = { 1.0f, 0.0f, 1.59602678f, 0.0f } },
+ { .f32 = { 1.0f, -0.39176229f, -0.81296764f, 0.0f } },
+ { .f32 = { 1.0f, 2.01723214f, 0.0f, 0.0f } }
+ };
+
+ nir_ssa_def *yuv =
+ nir_vec4(b,
+ nir_fmul(b, nir_imm_float(b, 1.16438356f),
+ nir_fadd(b, y, nir_imm_float(b, -16.0f /
255.0f))),
+ nir_channel(b, nir_fadd(b, u, nir_imm_float(b,
-128.0f / 255.0f)), 0),
+ nir_channel(b, nir_fadd(b, v, nir_imm_float(b,
-128.0f / 255.0f)), 0),
+ nir_imm_float(b, 0.0));
+
+ nir_ssa_def *red = nir_fdot4(b, yuv, nir_build_imm(b, 4, 32,
m[0]));
+ nir_ssa_def *green = nir_fdot4(b, yuv, nir_build_imm(b, 4,
32, m[1]));
+ nir_ssa_def *blue = nir_fdot4(b, yuv, nir_build_imm(b, 4, 32,
m[2]));
+
+ result = nir_vec4(b, red, green, blue, a);
+ }
nir_ssa_def_rewrite_uses(&tex->dest.ssa, nir_src_for_ssa(result));
}
