panfrost: Don't unroll loops in GLSL

GLSL loop analysis is trouble. Just use NIR.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10392>

src/gallium/drivers/panfrost/pan_screen.c

@@ -404,19 +404,15 @@ panfrost_get_shader_param(struct pipe_screen *screen,
         case PIPE_SHADER_CAP_SUPPORTED_IRS:
                 return (1 << PIPE_SHADER_IR_NIR) | (1 << PIPE_SHADER_IR_NIR_SERIALIZED);
 
-        case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
-                return 32;
-
         case PIPE_SHADER_CAP_MAX_SHADER_BUFFERS:
                 return is_deqp ? 16 : 0;
 
         case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
                 return (pan_is_bifrost(dev) && !is_deqp) ? 0 : PIPE_MAX_SHADER_IMAGES;
 
+        case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
         case PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTERS:
         case PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTER_BUFFERS:
-                return 0;
-
         case PIPE_SHADER_CAP_TGSI_SKIP_MERGE_REGISTERS:
         case PIPE_SHADER_CAP_LOWER_IF_THRESHOLD:
                 return 0;

src/panfrost/bifrost/bifrost_compile.h

@@ -90,6 +90,7 @@ static const nir_shader_compiler_options bifrost_nir_options = {
 
         .has_cs_global_id = true,
         .lower_cs_local_index_from_id = true,
+        .max_unroll_iterations = 32,
 };
 
 #endif

src/panfrost/midgard/midgard_compile.h

@@ -92,6 +92,7 @@ static const nir_shader_compiler_options midgard_nir_options = {
 
         .has_cs_global_id = true,
         .lower_cs_local_index_from_id = true,
+        .max_unroll_iterations = 32,
 };
 
 #endif