nir: Add a nir_instr_remove that recursively removes dead code.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11628>
2021-06-25 16:53:55 -07:00
parent d8d7d475aa
commit 5251548572
6 changed files with 231 additions and 0 deletions
@@ -0,0 +1,126 @@
+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * 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 <gtest/gtest.h>
+
+#include "nir.h"
+#include "nir_builder.h"
+
+namespace {
+
+class nir_core_test : public ::testing::Test {
+protected:
+   nir_core_test();
+   ~nir_core_test();
+
+   bool shader_contains_def(nir_ssa_def *def);
+
+   nir_builder *b, _b;
+};
+
+nir_core_test::nir_core_test()
+{
+   glsl_type_singleton_init_or_ref();
+
+   static const nir_shader_compiler_options options = { };
+   _b = nir_builder_init_simple_shader(MESA_SHADER_COMPUTE, &options, "builder test");
+   b = &_b;
+}
+
+nir_core_test::~nir_core_test()
+{
+   if (HasFailure()) {
+      printf("\nShader from the failed test:\n\n");
+      nir_print_shader(b->shader, stdout);
+   }
+
+   ralloc_free(b->shader);
+
+   glsl_type_singleton_decref();
+}
+
+struct contains_def_state {
+   nir_ssa_def *def;
+   bool found;
+};
+
+static bool
+contains_def_cb(nir_ssa_def *def, void *_state)
+{
+   struct contains_def_state *state = (struct contains_def_state *)_state;
+   if (def == state->def)
+      state->found = true;
+
+   return true;
+}
+
+bool
+nir_core_test::shader_contains_def(nir_ssa_def *def)
+{
+   nir_foreach_block(block, b->impl) {
+      nir_foreach_instr(instr, block) {
+         struct contains_def_state state = {
+            .def = def,
+            .found = false,
+         };
+         nir_foreach_ssa_def(instr, contains_def_cb, &state);
+         if (state.found)
+            return true;
+      }
+   }
+   return false;
+}
+
+TEST_F(nir_core_test, nir_instr_remove_and_dce_test)
+{
+   nir_ssa_def *zero = nir_imm_int(b, 0);
+   nir_ssa_def *one = nir_imm_int(b, 1);
+   nir_ssa_def *add01 = nir_iadd(b, zero, one);
+   nir_ssa_def *add11 = nir_iadd(b, one, one);
+
+   nir_cursor c = nir_instr_remove_and_dce(add01->parent_instr);
+   ASSERT_FALSE(shader_contains_def(add01));
+   ASSERT_TRUE(shader_contains_def(add11));
+   ASSERT_FALSE(shader_contains_def(zero));
+   ASSERT_TRUE(shader_contains_def(one));
+
+   ASSERT_TRUE(nir_cursors_equal(c, nir_before_instr(add11->parent_instr)));
+
+   nir_validate_shader(b->shader, "after remove_and_dce");
+}
+
+TEST_F(nir_core_test, nir_instr_remove_and_dce_all_test)
+{
+   nir_ssa_def *one = nir_imm_int(b, 1);
+   nir_ssa_def *add = nir_iadd(b, one, one);
+
+   nir_cursor c = nir_instr_remove_and_dce(add->parent_instr);
+   ASSERT_FALSE(shader_contains_def(add));
+   ASSERT_FALSE(shader_contains_def(one));
+
+   ASSERT_TRUE(nir_cursors_equal(c, nir_before_block(nir_start_block(b->impl))));
+
+   nir_validate_shader(b->shader, "after remove_and_dce");
+}
+
+}