glsl: Add unit tests for the lower_precision pass

Adds a unit tests script that invokes the standalone compiler with
--lower-precision and verifies that lowered operations are being used.

Reviewed-by: Alyssa Rosenzweig <[email protected]>
Reviewed-by: Kristian H. Kristensen <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3885>

2 files changed, 400 insertions, 0 deletions

diff --git a/src/compiler/glsl/tests/lower_precision_test.py b/src/compiler/glsl/tests/lower_precision_test.py
new file mode 100644
index 00000000000..6d6e1271711
--- /dev/null
+++ b/src/compiler/glsl/tests/lower_precision_test.py
@@ -0,0 +1,392 @@
+# encoding=utf-8
+# Copyright © 2019 Google
+
+# 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 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.
+
+from __future__ import print_function
+import sys
+import subprocess
+import tempfile
+import re
+from collections import namedtuple
+
+
+Test = namedtuple("Test", "name source match_re")
+
+
+TESTS = [
+    Test("simple division",
+         """
+         uniform mediump float a, b;
+
+         void main()
+         {
+                 gl_FragColor.rgba = vec4(a / b);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("dot",
+         """
+         uniform mediump vec2 a, b;
+
+         void main()
+         {
+                 gl_FragColor.rgba = vec4(dot(a, b));
+         }
+         """,
+         r'\(expression +float16_t +dot\b'),
+    Test("array with const index",
+         """
+         precision mediump float;
+
+         uniform float in_simple[2];
+
+         void main()
+         {
+                 gl_FragColor = vec4(in_simple[0] / in_simple[1]);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("array with uniform index",
+         """
+         precision mediump float;
+
+         uniform float in_simple[2];
+         uniform int i0, i1;
+
+         void main()
+         {
+                 gl_FragColor = vec4(in_simple[i0] / in_simple[i1]);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("array-of-array with const index",
+         """
+         #version 310 es
+         precision mediump float;
+
+         uniform float in_aoa[2][2];
+
+         layout(location = 0) out float out_color;
+
+         void main()
+         {
+                 out_color = in_aoa[0][0] / in_aoa[1][1];
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("array-of-array with uniform index",
+         """
+         #version 310 es
+         precision mediump float;
+
+         uniform float in_aoa[2][2];
+         uniform int i0, i1;
+
+         layout(location = 0) out float out_color;
+
+         void main()
+         {
+                 out_color = in_aoa[i0][i0] / in_aoa[i1][i1];
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("array index",
+         """
+         uniform mediump float a, b;
+         uniform mediump float values[2];
+
+         void main()
+         {
+                 gl_FragColor.rgba = vec4(values[int(a / b)]);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("function",
+         """
+         precision mediump float;
+
+         uniform float a, b;
+
+         mediump float
+         get_a()
+         {
+                 return a;
+         }
+
+         float
+         get_b()
+         {
+                 return b;
+         }
+
+         void main()
+         {
+                 gl_FragColor = vec4(get_a() / get_b());
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("function mediump args",
+         """
+         precision mediump float;
+
+         uniform float a, b;
+
+         mediump float
+         do_div(float x, float y)
+         {
+                 return x / y;
+         }
+
+         void main()
+         {
+                 gl_FragColor = vec4(do_div(a, b));
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("function highp args",
+         """
+         precision mediump float;
+
+         uniform float a, b;
+
+         mediump float
+         do_div(highp float x, highp float y)
+         {
+                 return x / y;
+         }
+
+         void main()
+         {
+                 gl_FragColor = vec4(do_div(a, b));
+         }
+         """,
+         r'\(expression +float +/'),
+    Test("function inout different precision highp",
+         """
+         uniform mediump float a, b;
+
+         void
+         do_div(inout highp float x, highp float y)
+         {
+                 x = x / y;
+         }
+
+         void main()
+         {
+                 mediump float temp = a;
+                 do_div(temp, b);
+                 gl_FragColor = vec4(temp);
+         }
+         """,
+         r'\(expression +float +/'),
+    Test("function inout different precision mediump",
+         """
+         uniform highp float a, b;
+
+         void
+         do_div(inout mediump float x, mediump float y)
+         {
+                 x = x / y;
+         }
+
+         void main()
+         {
+                 highp float temp = a;
+                 do_div(temp, b);
+                 gl_FragColor = vec4(temp);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("if",
+         """
+         precision mediump float;
+
+         uniform float a, b;
+
+         void
+         main()
+         {
+                 if (a / b < 0.31)
+                         gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
+                 else
+                         gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("matrix",
+         """
+         precision mediump float;
+
+         uniform vec2 a;
+         uniform mat2 b;
+
+         void main()
+         {
+             gl_FragColor = vec4(b * a, 0.0, 0.0);
+         }
+         """,
+         r'\(expression +f16vec2 \*.*\bf16mat2\b'),
+    Test("simple struct deref",
+         """
+         precision mediump float;
+
+         struct simple {
+                 float a, b;
+         };
+
+         uniform simple in_simple;
+
+         void main()
+         {
+                 gl_FragColor = vec4(in_simple.a / in_simple.b);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("embedded struct deref",
+         """
+         precision mediump float;
+
+         struct simple {
+                 float a, b;
+         };
+
+         struct embedded {
+                 simple a, b;
+         };
+
+         uniform embedded in_embedded;
+
+         void main()
+         {
+                 gl_FragColor = vec4(in_embedded.a.a / in_embedded.b.b);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("arrayed struct deref",
+         """
+         precision mediump float;
+
+         struct simple {
+                 float a, b;
+         };
+
+         struct arrayed {
+                 simple a[2];
+         };
+
+         uniform arrayed in_arrayed;
+
+         void main()
+         {
+                 gl_FragColor = vec4(in_arrayed.a[0].a / in_arrayed.a[1].b);
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("mixed precision not lowered",
+         """
+         uniform mediump float a;
+         uniform highp float b;
+
+         void main()
+         {
+                 gl_FragColor = vec4(a / b);
+         }
+         """,
+         r'\(expression +float +/'),
+    Test("texture sample",
+         """
+         precision mediump float;
+
+         uniform sampler2D tex;
+         uniform vec2 coord;
+         uniform float divisor;
+
+         void main()
+         {
+                 gl_FragColor = texture2D(tex, coord) / divisor;
+         }
+         """,
+         r'\(expression +f16vec4 +/'),
+    Test("expression in lvalue",
+         """
+         uniform mediump float a, b;
+
+         void main()
+         {
+                 gl_FragColor = vec4(1.0);
+                 gl_FragColor[int(a / b)] = 0.5;
+         }
+         """,
+         r'\(expression +float16_t +/'),
+    Test("builtin with const arg",
+         """
+         uniform mediump float a;
+
+         void main()
+         {
+                 gl_FragColor = vec4(min(a, 3.0));
+         }
+         """,
+         r'\(expression +float16_t min'),
+]
+
+
+def compile_shader(standalone_compiler, source):
+    with tempfile.NamedTemporaryFile(mode='wt', suffix='.frag') as source_file:
+        print(source, file=source_file)
+        source_file.flush()
+        return subprocess.check_output([standalone_compiler,
+                                        '--version', '300',
+                                        '--lower-precision',
+                                        '--dump-lir',
+                                        source_file.name],
+                                       universal_newlines=True)
+
+
+def run_test(standalone_compiler, test):
+    ir = compile_shader(standalone_compiler, test.source)
+
+    if re.search(test.match_re, ir) is None:
+        return False
+
+    return True
+
+
+def main():
+    standalone_compiler = sys.argv[1]
+    passed = 0
+
+    for test in TESTS:
+        print('Testing {} ... '.format(test.name), end='')
+
+        result = run_test(standalone_compiler, test)
+
+        if result:
+            print('PASS')
+            passed += 1
+        else:
+            print('FAIL')
+
+    print('{}/{} tests returned correct results'.format(passed, len(TESTS)))
+    sys.exit(0 if passed == len(TESTS) else 1)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/src/compiler/glsl/tests/meson.build b/src/compiler/glsl/tests/meson.build
index 5914627e194..3526110dbc1 100644
--- a/src/compiler/glsl/tests/meson.build
+++ b/src/compiler/glsl/tests/meson.build
@@ -110,4 +110,12 @@ if with_tools.contains('glsl')
            ],
     suite : ['compiler', 'glsl'],
   )
+  test(
+    'glsl lower-precision test',
+    prog_python,
+    args : [join_paths(meson.current_source_dir(), 'lower_precision_test.py'),
+            glsl_compiler
+           ],
+    suite : ['compiler', 'glsl'],
+  )
 endif