glsl: when NIR linker enable use it to resize uniform arrays

Here we turn on uniform array resizing in the NIR linker and disable
the GLSL IR resizing pass when the NIR linker is enabled.

This will potentially make uniform arrays smaller due to NIR
optimising away more uniform uses.

Shader-db results (SKL):

total instructions in shared programs: 14947192 -> 14944093 (-0.02%)
instructions in affected programs: 138088 -> 134989 (-2.24%)
helped: 822
HURT: 4

total cycles in shared programs: 324868402 -> 324794597 (-0.02%)
cycles in affected programs: 3904170 -> 3830365 (-1.89%)
helped: 2333
HURT: 1485

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4910>

2 files changed, 24 insertions, 13 deletions

diff --git a/src/compiler/glsl/gl_nir_link_uniforms.c b/src/compiler/glsl/gl_nir_link_uniforms.c
index 9806da393ab..b1187c45dc1 100644
--- a/src/compiler/glsl/gl_nir_link_uniforms.c
+++ b/src/compiler/glsl/gl_nir_link_uniforms.c
@@ -1522,6 +1522,17 @@ gl_nir_link_uniforms(struct gl_context *ctx,
       add_var_use_shader(nir, state.referenced_uniforms[stage]);
    }
 
+   /* Resize uniform arrays based on the maximum array index */
+   for (unsigned stage = 0; stage < MESA_SHADER_STAGES; stage++) {
+      struct gl_linked_shader *sh = prog->_LinkedShaders[stage];
+      if (!sh)
+         continue;
+
+      nir_shader *nir = sh->Program->nir;
+      nir_foreach_variable(var, &nir->uniforms)
+         update_array_sizes(prog, var, state.referenced_uniforms);
+   }
+
    /* Count total number of uniforms and allocate storage */
    unsigned storage_size = 0;
    if (!prog->data->spirv) {
diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index a674726312f..8761c16e2fe 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4444,21 +4444,20 @@ static void
 link_and_validate_uniforms(struct gl_context *ctx,
                            struct gl_shader_program *prog)
 {
-   update_array_sizes(prog);
+   assert(!ctx->Const.UseNIRGLSLLinker);
 
-   if (!ctx->Const.UseNIRGLSLLinker) {
-      link_assign_uniform_locations(prog, ctx);
+   update_array_sizes(prog);
+   link_assign_uniform_locations(prog, ctx);
 
-      if (prog->data->LinkStatus == LINKING_FAILURE)
-         return;
+   if (prog->data->LinkStatus == LINKING_FAILURE)
+      return;
 
-      link_util_calculate_subroutine_compat(prog);
-      link_util_check_uniform_resources(ctx, prog);
-      link_util_check_subroutine_resources(prog);
-      check_image_resources(ctx, prog);
-      link_assign_atomic_counter_resources(ctx, prog);
-      link_check_atomic_counter_resources(ctx, prog);
-   }
+   link_util_calculate_subroutine_compat(prog);
+   link_util_check_uniform_resources(ctx, prog);
+   link_util_check_subroutine_resources(prog);
+   check_image_resources(ctx, prog);
+   link_assign_atomic_counter_resources(ctx, prog);
+   link_check_atomic_counter_resources(ctx, prog);
 }
 
 static bool
@@ -4505,7 +4504,8 @@ link_varyings_and_uniforms(unsigned first, unsigned last,
    if (!link_varyings(prog, first, last, ctx, mem_ctx))
       return false;
 
-   link_and_validate_uniforms(ctx, prog);
+   if (!ctx->Const.UseNIRGLSLLinker)
+      link_and_validate_uniforms(ctx, prog);
 
    if (!prog->data->LinkStatus)
       return false;