--- /dev/null
+/*
+ * Copyright © 2022 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"
+
+class nir_loop_analyze_test : public ::testing::Test {
+protected:
+ nir_loop_analyze_test();
+ ~nir_loop_analyze_test();
+
+ nir_builder b;
+};
+
+nir_loop_analyze_test::nir_loop_analyze_test()
+{
+ glsl_type_singleton_init_or_ref();
+
+ static const nir_shader_compiler_options options = { };
+ b = nir_builder_init_simple_shader(MESA_SHADER_VERTEX, &options,
+ "loop analyze");
+}
+
+nir_loop_analyze_test::~nir_loop_analyze_test()
+{
+ ralloc_free(b.shader);
+ glsl_type_singleton_decref();
+}
+
+TEST_F(nir_loop_analyze_test, infinite_loop_feq)
+{
+ /* Create IR:
+ *
+ * float i = 0.0;
+ * while (true) {
+ * if (i == 0.9)
+ * break;
+ *
+ * i = i + 0.2;
+ * }
+ */
+ nir_ssa_def *ssa_0 = nir_imm_int(&b, 0x00000000);
+ nir_ssa_def *ssa_1 = nir_imm_int(&b, 0x3e4ccccd);
+ nir_ssa_def *ssa_2 = nir_imm_int(&b, 0x3f666666);
+
+ nir_phi_instr *const phi = nir_phi_instr_create(b.shader);
+
+ nir_loop *loop = nir_push_loop(&b);
+ {
+ nir_ssa_dest_init(&phi->instr, &phi->dest,
+ ssa_0->num_components, ssa_0->bit_size,
+ NULL);
+
+ nir_phi_instr_add_src(phi, ssa_0->parent_instr->block,
+ nir_src_for_ssa(ssa_0));
+
+ nir_ssa_def *ssa_5 = &phi->dest.ssa;
+ nir_ssa_def *ssa_3 = nir_feq(&b, ssa_5, ssa_1);
+
+ nir_if *nif = nir_push_if(&b, ssa_3);
+ {
+ nir_jump_instr *jump = nir_jump_instr_create(b.shader, nir_jump_break);
+ nir_builder_instr_insert(&b, &jump->instr);
+ }
+ nir_pop_if(&b, nif);
+
+ nir_ssa_def *ssa_4 = nir_fadd(&b, ssa_5, ssa_2);
+
+ nir_phi_instr_add_src(phi, ssa_4->parent_instr->block,
+ nir_src_for_ssa(ssa_4));
+ }
+ nir_pop_loop(&b, loop);
+
+ b.cursor = nir_before_block(nir_loop_first_block(loop));
+ nir_builder_instr_insert(&b, &phi->instr);
+
+ /* At this point, we should have:
+ *
+ * impl main {
+ * block block_0:
+ * // preds:
+ * vec1 32 ssa_0 = load_const (0x00000000 = 0.000000)
+ * vec1 32 ssa_1 = load_const (0x3e4ccccd = 0.900000)
+ * vec1 32 ssa_2 = load_const (0x3f666666 = 0.200000)
+ * // succs: block_1
+ * loop {
+ * block block_1:
+ * // preds: block_0 block_4
+ * vec1 32 ssa_5 = phi block_0: ssa_0, block_4: ssa_4
+ * vec1 1 ssa_3 = feq ssa_5, ssa_1
+ * // succs: block_2 block_3
+ * if ssa_3 {
+ * block block_2:
+ * // preds: block_1
+ * break
+ * // succs: block_5
+ * } else {
+ * block block_3:
+ * // preds: block_1
+ * // succs: block_4
+ * }
+ * block block_4:
+ * // preds: block_3
+ * vec1 32 ssa_4 = fadd ssa_5, ssa_2
+ * // succs: block_1
+ * }
+ * block block_5:
+ * // preds: block_2
+ * // succs: block_6
+ * block block_6:
+ * }
+ */
+ nir_validate_shader(b.shader, "input");
+
+ nir_loop_analyze_impl(b.impl, nir_var_all, false);
+
+ ASSERT_NE((void *)0, loop->info);
+ EXPECT_FALSE(loop->info->guessed_trip_count);
+ EXPECT_FALSE(loop->info->exact_trip_count_known);
+ EXPECT_EQ((void *)0, loop->info->limiting_terminator);
+}
+
+TEST_F(nir_loop_analyze_test, zero_iterations_ine)
+{
+ /* Create IR:
+ *
+ * uint i = 1;
+ * while (true) {
+ * if (i != 0)
+ * break;
+ *
+ * i++;
+ * }
+ *
+ * This loop should have an iteration count of zero. See also
+ * https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19732#note_1648999
+ */
+ nir_ssa_def *ssa_0 = nir_imm_int(&b, 0);
+ nir_ssa_def *ssa_1 = nir_imm_int(&b, 1);
+
+ nir_phi_instr *const phi = nir_phi_instr_create(b.shader);
+
+ nir_loop *loop = nir_push_loop(&b);
+ {
+ nir_ssa_dest_init(&phi->instr, &phi->dest,
+ ssa_1->num_components, ssa_1->bit_size,
+ NULL);
+
+ nir_phi_instr_add_src(phi, ssa_1->parent_instr->block,
+ nir_src_for_ssa(ssa_1));
+
+ nir_ssa_def *ssa_4 = &phi->dest.ssa;
+ nir_ssa_def *ssa_2 = nir_ine(&b, ssa_4, ssa_0);
+
+ nir_if *nif = nir_push_if(&b, ssa_2);
+ {
+ nir_jump_instr *jump = nir_jump_instr_create(b.shader, nir_jump_break);
+ nir_builder_instr_insert(&b, &jump->instr);
+ }
+ nir_pop_if(&b, nif);
+
+ nir_ssa_def *ssa_3 = nir_iadd(&b, ssa_4, ssa_1);
+
+ nir_phi_instr_add_src(phi, ssa_3->parent_instr->block,
+ nir_src_for_ssa(ssa_3));
+ }
+ nir_pop_loop(&b, loop);
+
+ b.cursor = nir_before_block(nir_loop_first_block(loop));
+ nir_builder_instr_insert(&b, &phi->instr);
+
+ /* At this point, we should have:
+ *
+ * impl main {
+ * block block_0:
+ * // preds:
+ * vec1 32 ssa_0 = load_const (0x00000000 = 0.000000)
+ * vec1 32 ssa_1 = load_const (0x00000001 = 0.000000)
+ * // succs: block_1
+ * loop {
+ * block block_1:
+ * // preds: block_0 block_4
+ * vec1 32 ssa_4 = phi block_0: ssa_1, block_4: ssa_3
+ * vec1 1 ssa_2 = ine ssa_4, ssa_0
+ * // succs: block_2 block_3
+ * if ssa_2 {
+ * block block_2:
+ * // preds: block_1
+ * break
+ * // succs: block_5
+ * } else {
+ * block block_3:
+ * // preds: block_1
+ * // succs: block_4
+ * }
+ * block block_4:
+ * // preds: block_3
+ * vec1 32 ssa_3 = iadd ssa_4, ssa_1
+ * // succs: block_1
+ * }
+ * block block_5:
+ * // preds: block_2
+ * // succs: block_6
+ * block block_6:
+ * }
+ */
+ nir_validate_shader(b.shader, "input");
+
+ nir_loop_analyze_impl(b.impl, nir_var_all, false);
+
+ ASSERT_NE((void *)0, loop->info);
+ EXPECT_EQ(0, loop->info->max_trip_count);
+ EXPECT_TRUE(loop->info->exact_trip_count_known);
+}
projects / platform / upstream / mesa.git / commitdiff