intel: Move slm functions from brw_compiler.h to intel_compute_slm.c/h

This functions were inlined in a header and duplicated between brw and
elk.
That would be enough reasons to move to a C file but next patches
will add more code to support Xe2 platforms, what would cause more
code to be inlined, duplicating even more code and increasing lib
size.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28910>

src/intel/common/intel_compute_slm.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024 Intel Corporation
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "intel_compute_slm.h"
+
+#include <assert.h>
+
+#include "util/macros.h"
+#include "util/u_math.h"
+
+/* Shared Local Memory Size is specified as powers of two,
+ * and also have a Gen-dependent minimum value if not zero.
+ */
+uint32_t
+intel_compute_slm_calculate_size(unsigned gen, uint32_t bytes)
+{
+   assert(bytes <= 64 * 1024);
+   if (bytes > 0)
+      return MAX2(util_next_power_of_two(bytes), gen >= 9 ? 1024 : 4096);
+   else
+      return 0;
+}
+
+uint32_t
+intel_compute_slm_encode_size(unsigned gen, uint32_t bytes)
+{
+   uint32_t slm_size = 0;
+
+   /* Shared Local Memory is specified as powers of two, and encoded in
+    * INTERFACE_DESCRIPTOR_DATA with the following representations:
+    *
+    * Size   | 0 kB | 1 kB | 2 kB | 4 kB | 8 kB | 16 kB | 32 kB | 64 kB |
+    * -------------------------------------------------------------------
+    * Gfx7-8 |    0 | none | none |    1 |    2 |     4 |     8 |    16 |
+    * -------------------------------------------------------------------
+    * Gfx9+  |    0 |    1 |    2 |    3 |    4 |     5 |     6 |     7 |
+    */
+
+   if (bytes > 0) {
+      slm_size = intel_compute_slm_calculate_size(gen, bytes);
+      assert(util_is_power_of_two_nonzero(slm_size));
+
+      if (gen >= 9) {
+         /* Turn an exponent of 10 (1024 kB) into 1. */
+         assert(slm_size >= 1024);
+         slm_size = ffs(slm_size) - 10;
+      } else {
+         assert(slm_size >= 4096);
+         /* Convert to the pre-Gfx9 representation. */
+         slm_size = slm_size / 4096;
+      }
+   }
+
+   return slm_size;
+}

src/intel/common/intel_compute_slm.h

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2024 Intel Corporation
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+uint32_t intel_compute_slm_calculate_size(unsigned gen, uint32_t bytes);
+uint32_t intel_compute_slm_encode_size(unsigned gen, uint32_t bytes);

src/intel/common/meson.build

@@ -36,6 +36,8 @@ files_libintel_common = files(
   'intel_bind_timeline.c',
   'intel_bind_timeline.h',
   'intel_buffer_alloc.h',
+  'intel_compute_slm.c',
+  'intel_compute_slm.h',
   'intel_debug_identifier.h',
   'intel_debug_identifier.c',
   'intel_engine.c',