SPIRV-Tools/test/opt/freeze_spec_const_test.cpp
Neil Roberts 57a2441791 hex_float: Use max_digits10 for the float precision
CPPreference.com has this description of digits10:

“The value of std::numeric_limits<T>::digits10 is the number of
 base-10 digits that can be represented by the type T without change,
 that is, any number with this many significant decimal digits can be
 converted to a value of type T and back to decimal form, without
 change due to rounding or overflow.”

This means that any number with this many digits can be represented
accurately in the corresponding type. A change in any digit in a
number after that may or may not cause it a different bitwise
representation. Therefore this isn’t necessarily enough precision to
accurately represent the value in text. Instead we need max_digits10
which has the following description:

“The value of std::numeric_limits<T>::max_digits10 is the number of
 base-10 digits that are necessary to uniquely represent all distinct
 values of the type T, such as necessary for
 serialization/deserialization to text.”

The patch includes a test case in hex_float_test which tries to do a
round-robin conversion of a number that requires more than 6 decimal
places to be accurately represented. This would fail without the
patch.

Sadly this also breaks a bunch of other tests. Some of the tests in
hex_float_test use ldexp and then compare it with a value which is not
the same as the one returned by ldexp but instead is the value rounded
to 6 decimals. Others use values that are not evenly representable as
a binary floating fraction but then happened to generate the same
value when rounded to 6 decimals. Where the actual value didn’t seem
to matter these have been changed with different values that can be
represented as a binary fraction.
2018-04-03 12:53:10 -04:00

129 lines
5.0 KiB
C++

// Copyright (c) 2016 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "pass_fixture.h"
#include "pass_utils.h"
#include <algorithm>
#include <tuple>
#include <vector>
namespace {
using namespace spvtools;
struct FreezeSpecConstantValueTypeTestCase {
const char* type_decl;
const char* spec_const;
const char* expected_frozen_const;
};
using FreezeSpecConstantValueTypeTest =
PassTest<::testing::TestWithParam<FreezeSpecConstantValueTypeTestCase>>;
TEST_P(FreezeSpecConstantValueTypeTest, PrimaryType) {
auto& test_case = GetParam();
std::vector<const char*> text = {"OpCapability Shader",
"OpMemoryModel Logical GLSL450",
test_case.type_decl, test_case.spec_const};
std::vector<const char*> expected = {
"OpCapability Shader", "OpMemoryModel Logical GLSL450",
test_case.type_decl, test_case.expected_frozen_const};
SinglePassRunAndCheck<opt::FreezeSpecConstantValuePass>(
JoinAllInsts(text), JoinAllInsts(expected), /* skip_nop = */ false);
}
// Test each primary type.
INSTANTIATE_TEST_CASE_P(
PrimaryTypeSpecConst, FreezeSpecConstantValueTypeTest,
::testing::ValuesIn(std::vector<FreezeSpecConstantValueTypeTestCase>({
// Type declaration, original spec constant definition, expected frozen
// spec constants.
{"%int = OpTypeInt 32 1", "%2 = OpSpecConstant %int 1",
"%int_1 = OpConstant %int 1"},
{"%uint = OpTypeInt 32 0", "%2 = OpSpecConstant %uint 1",
"%uint_1 = OpConstant %uint 1"},
{"%float = OpTypeFloat 32", "%2 = OpSpecConstant %float 3.1415",
"%float_3_1415 = OpConstant %float 3.1415"},
{"%double = OpTypeFloat 64", "%2 = OpSpecConstant %double 3.141592653",
"%double_3_141592653 = OpConstant %double 3.141592653"},
{"%bool = OpTypeBool", "%2 = OpSpecConstantTrue %bool",
"%true = OpConstantTrue %bool"},
{"%bool = OpTypeBool", "%2 = OpSpecConstantFalse %bool",
"%false = OpConstantFalse %bool"},
})));
using FreezeSpecConstantValueRemoveDecorationTest = PassTest<::testing::Test>;
TEST_F(FreezeSpecConstantValueRemoveDecorationTest,
RemoveDecorationInstWithSpecId) {
std::vector<const char*> text = {
// clang-format off
"OpCapability Shader",
"OpCapability Float64",
"%1 = OpExtInstImport \"GLSL.std.450\"",
"OpMemoryModel Logical GLSL450",
"OpEntryPoint Vertex %main \"main\"",
"OpSource GLSL 450",
"OpSourceExtension \"GL_GOOGLE_cpp_style_line_directive\"",
"OpSourceExtension \"GL_GOOGLE_include_directive\"",
"OpName %main \"main\"",
"OpDecorate %3 SpecId 200",
"OpDecorate %4 SpecId 201",
"OpDecorate %5 SpecId 202",
"OpDecorate %6 SpecId 203",
"%void = OpTypeVoid",
"%8 = OpTypeFunction %void",
"%int = OpTypeInt 32 1",
"%3 = OpSpecConstant %int 3",
"%float = OpTypeFloat 32",
"%4 = OpSpecConstant %float 3.1415",
"%double = OpTypeFloat 64",
"%5 = OpSpecConstant %double 3.14159265358979",
"%bool = OpTypeBool",
"%6 = OpSpecConstantTrue %bool",
"%13 = OpSpecConstantFalse %bool",
"%main = OpFunction %void None %8",
"%14 = OpLabel",
"OpReturn",
"OpFunctionEnd",
// clang-format on
};
std::string expected_disassembly = SelectiveJoin(text, [](const char* line) {
return std::string(line).find("SpecId") != std::string::npos;
});
std::vector<std::pair<const char*, const char*>> replacement_pairs = {
{"%3 = OpSpecConstant %int 3", "%int_3 = OpConstant %int 3"},
{"%4 = OpSpecConstant %float 3.1415",
"%float_3_1415 = OpConstant %float 3.1415"},
{"%5 = OpSpecConstant %double 3.14159265358979",
"%double_3_14159265358979 = OpConstant %double 3.14159265358979"},
{"%6 = OpSpecConstantTrue ", "%true = OpConstantTrue "},
{"%13 = OpSpecConstantFalse ", "%false = OpConstantFalse "},
};
for (auto& p : replacement_pairs) {
EXPECT_TRUE(FindAndReplace(&expected_disassembly, p.first, p.second))
<< "text:\n"
<< expected_disassembly << "\n"
<< "find_str:\n"
<< p.first << "\n"
<< "replace_str:\n"
<< p.second << "\n";
}
SinglePassRunAndCheck<opt::FreezeSpecConstantValuePass>(
JoinAllInsts(text), expected_disassembly,
/* skip_nop = */ true);
}
} // anonymous namespace