agx: Add sysval management helper

Will be used for lowering UBO loads, among other applications.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10582>

src/asahi/compiler/agx_compiler.h

@@ -542,6 +542,12 @@ agx_builder_insert(agx_cursor *cursor, agx_instr *I)
    unreachable("Invalid cursor option");
 }
 
+/* Uniform file management */
+
+agx_index
+agx_indexed_sysval(agx_context *ctx, enum agx_push_type type, enum agx_size size,
+      unsigned index, unsigned length);
+
 /* Routines defined for AIR */
 
 void agx_print_instr(agx_instr *I, FILE *fp);

src/asahi/compiler/agx_uniforms.c

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2021 Alyssa Rosenzweig <alyssa@rosenzweig.io>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "agx_compiler.h"
+
+/* Manages the uniform file. We can push certain fixed items (during initial
+ * code generation), where we're gauranteed to have sufficient space. After
+ * that, UBO ranges can be selectively pushed while there's space. */
+
+/* Directly index an array sysval. Index must be in bounds. Index specified in
+ * 16-bit units regardless of the underlying sysval's unit. */
+
+agx_index
+agx_indexed_sysval(agx_context *ctx, enum agx_push_type type,
+      enum agx_size size, unsigned index, unsigned length)
+{
+   /* Check if we already pushed */
+   for (unsigned i = 0; i < ctx->out->push_ranges; ++i) {
+      struct agx_push push = ctx->out->push[i];
+
+      if (push.type == type && !push.indirect) {
+         assert(length == push.length);
+         assert(index < push.length);
+         return agx_uniform(push.base + index, size);
+      }
+   }
+
+   /* Otherwise, push */
+   assert(ctx->out->push_ranges < AGX_MAX_PUSH_RANGES);
+
+   unsigned base = ctx->push_base;
+   ctx->push_base += length;
+
+   ctx->out->push[ctx->out->push_ranges++] = (struct agx_push) {
+      .type = type,
+      .base = base,
+      .length = length,
+      .indirect = false
+   };
+
+   return agx_uniform(base + index, size);
+}

src/asahi/compiler/meson.build

@@ -26,6 +26,7 @@ libasahi_agx_files = files(
   'agx_print.c',
   'agx_optimizer.c',
   'agx_register_allocate.c',
+  'agx_uniforms.c',
 )
 
 agx_opcodes_h = custom_target(