Mesa (main): softpipe: switch to NIR loop unrolling

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 3ceaf589d62ed81d74042219098c9428730ead99
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3ceaf589d62ed81d74042219098c9428730ead99

Author: Timothy Arceri <tarceri at itsqueeze.com>
Date:   Fri May  6 11:23:06 2022 +1000

softpipe: switch to NIR loop unrolling

shader-db results:

total instructions in shared programs: 2788746 -> 2788886 (<.01%)
instructions in affected programs: 2126 -> 2266 (6.59%)
total loops in shared programs: 1357 -> 892 (-34.27%)
loops in affected programs: 468 -> 3 (-99.36%)
total temps in shared programs: 288754 -> 288725 (-0.01%)
temps in affected programs: 1623 -> 1594 (-1.79%)
total const in shared programs: 1954525 -> 1954621 (<.01%)
const in affected programs: 207 -> 303 (46.38%)
total imm in shared programs: 101023 -> 100891 (-0.13%)
imm in affected programs: 198 -> 66 (-66.67%)

Reviewed-by: Emma Anholt <emma at anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16543>

---

 src/gallium/auxiliary/tgsi/tgsi_exec.h   | 4 +---
 src/gallium/drivers/softpipe/sp_screen.c | 1 +
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.h b/src/gallium/auxiliary/tgsi/tgsi_exec.h
index 226385ae3a3..bd3de6978ae 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.h
@@ -469,6 +469,7 @@ tgsi_exec_get_shader_param(enum pipe_shader_cap param)
    case PIPE_SHADER_CAP_FP16_CONST_BUFFERS:
    case PIPE_SHADER_CAP_INT16:
    case PIPE_SHADER_CAP_GLSL_16BIT_CONSTS:
+   case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
       return 0;
    case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS:
       return PIPE_MAX_SAMPLERS;
@@ -492,9 +493,6 @@ tgsi_exec_get_shader_param(enum pipe_shader_cap param)
       return PIPE_MAX_SHADER_BUFFERS;
    case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
       return PIPE_MAX_SHADER_IMAGES;
-
-   case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
-      return 32;
    }
    /* if we get here, we missed a shader cap above (and should have seen
     * a compiler warning.)
diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
index 6942fb328b0..7d84088e528 100644
--- a/src/gallium/drivers/softpipe/sp_screen.c
+++ b/src/gallium/drivers/softpipe/sp_screen.c
@@ -88,6 +88,7 @@ static const nir_shader_compiler_options sp_compiler_options = {
    .lower_rotate = true,
    .lower_uniforms_to_ubo = true,
    .lower_vector_cmp = true,
+   .max_unroll_iterations = 32,
    .use_interpolated_input_intrinsics = true,
 };