agx: add tests for SSA repair

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28483>

src/asahi/compiler/meson.build

@@ -109,6 +109,7 @@ if with_tests
          'test/test-lower-pseudo.cpp',
          'test/test-lower-parallel-copy.cpp',
          'test/test-lower-spill.cpp',
+         'test/test-repair-ssa.cpp',
       ),
       c_args : [c_msvc_compat_args, no_override_init_args],
       gnu_symbol_visibility : 'hidden',

src/asahi/compiler/test/test-repair-ssa.cpp

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2024 Alyssa Rosenzweig
+ * Copyright 2022 Collabora, Ltd.
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "agx_builder.h"
+#include "agx_compiler.h"
+#include "agx_test.h"
+
+#include <gtest/gtest.h>
+
+static void
+pass(agx_context *ctx)
+{
+   agx_repair_ssa(ctx);
+   agx_reindex_ssa(ctx);
+}
+
+#define CASE(instr)                                                            \
+   INSTRUCTION_CASE(                                                           \
+      {                                                                        \
+         bool repaired = false;                                                \
+         instr                                                                 \
+      },                                                                       \
+      {                                                                        \
+         bool repaired = true;                                                 \
+         instr                                                                 \
+      },                                                                       \
+      pass)
+
+class RepairSSA : public testing::Test {
+ protected:
+   RepairSSA()
+   {
+      mem_ctx = ralloc_context(NULL);
+   }
+
+   ~RepairSSA()
+   {
+      ralloc_free(mem_ctx);
+   }
+
+   void *mem_ctx;
+};
+
+static agx_index
+agx_phi_2(agx_builder *b, agx_index x, agx_index y)
+{
+   agx_index idx = agx_temp(b->shader, x.size);
+   agx_instr *phi = agx_phi_to(b, idx, 2);
+   phi->src[0] = x;
+   phi->src[1] = y;
+   return idx;
+}
+
+TEST_F(RepairSSA, Local)
+{
+   CASE({
+      agx_index x = agx_mov_imm(b, AGX_SIZE_32, 0xcafe);
+      agx_index y = agx_mov_imm(b, AGX_SIZE_32, 0xefac);
+
+      if (repaired) {
+         agx_unit_test(b, agx_fadd(b, y, x));
+      } else {
+         agx_fadd_to(b, x, y, x);
+         agx_unit_test(b, x);
+      }
+   });
+}
+
+/*      A
+ *     / \
+ *    B   C
+ *     \ /
+ *      D
+ */
+TEST_F(RepairSSA, IfElse)
+{
+   CASE({
+      agx_block *A = agx_start_block(b->shader);
+      agx_block *B = agx_test_block(b->shader);
+      agx_block *C = agx_test_block(b->shader);
+      agx_block *D = agx_test_block(b->shader);
+
+      agx_block_add_successor(A, B);
+      agx_block_add_successor(A, C);
+
+      agx_block_add_successor(B, D);
+      agx_block_add_successor(C, D);
+
+      b->cursor = agx_after_block(B);
+      agx_index x = agx_mov_imm(b, 32, 0xcafe);
+      agx_index y = agx_mov_imm(b, 32, 0xbade);
+
+      b->cursor = agx_after_block(C);
+      agx_index x2 = repaired ? agx_temp(b->shader, AGX_SIZE_32) : x;
+      agx_mov_imm_to(b, x2, 0xefac);
+      agx_index y2 = agx_mov_imm(b, 32, 0xbade);
+
+      b->cursor = agx_after_block(D);
+      if (repaired)
+         x = agx_phi_2(b, x, x2);
+
+      agx_index y3 = agx_phi_2(b, y, y2);
+      agx_unit_test(b, agx_fadd(b, x, y3));
+   });
+}