Preserve float values during encoding and decoding roundtrip.

CMakeLists.txt

@@ -96,6 +96,7 @@ include_directories(
 
 set(SPIRV_SOURCES
   ${CMAKE_CURRENT_SOURCE_DIR}/include/libspirv/libspirv.h
+  ${CMAKE_CURRENT_SOURCE_DIR}/include/utils/bitwisecast.h
   ${CMAKE_CURRENT_SOURCE_DIR}/source/binary.h
   ${CMAKE_CURRENT_SOURCE_DIR}/source/diagnostic.h
   ${CMAKE_CURRENT_SOURCE_DIR}/source/opcode.h

include/utils/bitwisecast.h

@@ -0,0 +1,41 @@
+// Copyright (c) 2015 The Khronos Group Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and/or associated documentation files (the
+// "Materials"), to deal in the Materials without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Materials, and to
+// permit persons to whom the Materials are 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 Materials.
+//
+// MODIFICATIONS TO THIS FILE MAY MEAN IT NO LONGER ACCURATELY REFLECTS
+// KHRONOS STANDARDS. THE UNMODIFIED, NORMATIVE VERSIONS OF KHRONOS
+// SPECIFICATIONS AND HEADER INFORMATION ARE LOCATED AT
+//    https://www.khronos.org/registry/
+//
+// THE MATERIALS ARE 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
+// MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+
+#include <cstring>
+
+namespace spvutils {
+
+// Performs a bitwise copy of source to the destination type Dest.
+template <typename Dest, typename Src>
+Dest BitwiseCast(Src source) {
+  Dest dest;
+  static_assert(sizeof(source) == sizeof(dest),
+                "BitwiseCast: Source and destination must have the same size");
+  std::memcpy(&dest, &source, sizeof(dest));
+  return dest;
+}
+
+}  // namespace spvutils

source/text.cpp

@@ -25,6 +25,8 @@
 // MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 
 #include <libspirv/libspirv.h>
+#include <utils/bitwisecast.h>
+
 #include "binary.h"
 #include "diagnostic.h"
 #include "ext_inst.h"
@@ -41,6 +43,8 @@
 #include <vector>
 #include <unordered_map>
 
+using spvutils::BitwiseCast;
+
 // Structures
 
 struct spv_named_id_table_t {
@@ -434,13 +438,13 @@ spv_result_t spvTextEncodeOperand(
                return SPV_ERROR_INVALID_TEXT);
       switch (literal.type) {
         case SPV_LITERAL_TYPE_INT_32:
-          spvCheck(spvBinaryEncodeU32((uint32_t)literal.value.i32, pInst,
-                                      position, pDiagnostic),
+          spvCheck(spvBinaryEncodeU32(BitwiseCast<uint32_t>(literal.value.i32),
+                                      pInst, position, pDiagnostic),
                    return SPV_ERROR_INVALID_TEXT);
           break;
         case SPV_LITERAL_TYPE_INT_64: {
-          spvCheck(spvBinaryEncodeU64((uint64_t)literal.value.i64, pInst,
-                                      position, pDiagnostic),
+          spvCheck(spvBinaryEncodeU64(BitwiseCast<uint64_t>(literal.value.i64),
+                                      pInst, position, pDiagnostic),
                    return SPV_ERROR_INVALID_TEXT);
         } break;
         case SPV_LITERAL_TYPE_UINT_32: {
@@ -449,18 +453,18 @@ spv_result_t spvTextEncodeOperand(
                    return SPV_ERROR_INVALID_TEXT);
         } break;
         case SPV_LITERAL_TYPE_UINT_64: {
-          spvCheck(spvBinaryEncodeU64((uint64_t)literal.value.u64, pInst,
-                                      position, pDiagnostic),
+          spvCheck(spvBinaryEncodeU64(BitwiseCast<uint64_t>(literal.value.u64),
+                                      pInst, position, pDiagnostic),
                    return SPV_ERROR_INVALID_TEXT);
         } break;
         case SPV_LITERAL_TYPE_FLOAT_32: {
-          spvCheck(spvBinaryEncodeU32((uint32_t)literal.value.f, pInst,
-                                      position, pDiagnostic),
+          spvCheck(spvBinaryEncodeU32(BitwiseCast<uint32_t>(literal.value.f),
+                                      pInst, position, pDiagnostic),
                    return SPV_ERROR_INVALID_TEXT);
         } break;
         case SPV_LITERAL_TYPE_FLOAT_64: {
-          spvCheck(spvBinaryEncodeU64((uint64_t)literal.value.d, pInst,
-                                      position, pDiagnostic),
+          spvCheck(spvBinaryEncodeU64(BitwiseCast<uint64_t>(literal.value.d),
+                                      pInst, position, pDiagnostic),
                    return SPV_ERROR_INVALID_TEXT);
         } break;
         case SPV_LITERAL_TYPE_STRING: {

test/TestFixture.h

@@ -93,6 +93,35 @@ class TextToBinaryTestBase : public T {
     return diagnostic->error;
   }
 
+  // Encodes SPIR-V text into binary and then decodes the binary. Returns the
+  // decoded text.
+  std::string EncodeAndDecodeSuccessfully(const std::string& text_string) {
+    SetText(text_string);
+    DestroyBinary();
+    spv_result_t error = spvTextToBinary(&text, opcodeTable, operandTable,
+                                         extInstTable, &binary, &diagnostic);
+    if (error) {
+      spvDiagnosticPrint(diagnostic);
+      spvDiagnosticDestroy(diagnostic);
+    }
+    EXPECT_EQ(SPV_SUCCESS, error);
+
+    spv_text decoded_text;
+    error =
+        spvBinaryToText(binary, SPV_BINARY_TO_TEXT_OPTION_NONE, opcodeTable,
+                        operandTable, extInstTable, &decoded_text, &diagnostic);
+    if (error) {
+      spvDiagnosticPrint(diagnostic);
+      spvDiagnosticDestroy(diagnostic);
+    }
+    EXPECT_EQ(SPV_SUCCESS, error);
+
+    const std::string decoded_string = decoded_text->str;
+    spvTextDestroy(decoded_text);
+
+    return decoded_string;
+  }
+
   void SetText(const std::string& code) {
     textString = code;
     text.str = textString.c_str();

test/TextToBinary.cpp

@@ -24,6 +24,7 @@
 // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 // MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 
+#include <utils/bitwisecast.h>
 #include "TestFixture.h"
 #include "UnitSPIRV.h"
 #include <algorithm>
@@ -33,6 +34,7 @@
 
 namespace {
 
+using spvutils::BitwiseCast;
 using test_fixture::TextToBinaryTest;
 
 union char_word_t {
@@ -403,23 +405,36 @@ TEST_F(TextToBinaryTest, BadSwitchTruncatedCase) {
   EXPECT_STREQ("Expected operand, found next instruction instead.", diagnostic->error);
 }
 
-using TextToBinaryFloatValueTest =
-    test_fixture::TextToBinaryTestBase<::testing::TestWithParam<float>>;
+using TextToBinaryFloatValueTest = test_fixture::TextToBinaryTestBase<
+    ::testing::TestWithParam<std::pair<std::string, uint32_t>>>;
 
-// TODO(dneto): Fix float parsing.
-TEST_P(TextToBinaryFloatValueTest, DISABLED_NormalValues) {
-  std::stringstream input;
-  input <<
-      R"(OpTypeFloat %float 32
-         %constval = OpConstant %float )"
-        << GetParam();
-  const SpirvVector code = CompileSuccessfully(input.str());
-
-  EXPECT_EQ(code[6], GetParam());
+TEST_P(TextToBinaryFloatValueTest, NormalValues) {
+  const std::string assembly = "%1 = OpTypeFloat 32\n%2 = OpConstant %1 ";
+  const std::string input_string = assembly + GetParam().first;
+  const std::string expected_string =
+      "; SPIR-V\n; Version: 99\n; Generator: Khronos\n; "
+      "Bound: 3\n; Schema: 0\n" +
+      assembly + std::to_string(GetParam().second) + "\n";
+  const std::string decoded_string = EncodeAndDecodeSuccessfully(input_string);
+  EXPECT_EQ(expected_string, decoded_string);
 }
 
-INSTANTIATE_TEST_CASE_P(float, TextToBinaryFloatValueTest,
-                        ::testing::ValuesIn(std::vector<float>{1.5, 0.0,
-                                                               -2.5}));
+INSTANTIATE_TEST_CASE_P(
+    FloatValues, TextToBinaryFloatValueTest,
+    ::testing::ValuesIn(std::vector<std::pair<std::string, uint32_t>>{
+        {"0.0", 0x00000000},          // +0
+        {"!0x00000001", 0x00000001},  // +denorm
+        {"!0x00800000", 0x00800000},  // +norm
+        {"1.5", 0x3fc00000},
+        {"!0x7f800000", 0x7f800000},  // +inf
+        {"!0x7f800001", 0x7f800001},  // NaN
+
+        {"-0.0", 0x80000000},         // -0
+        {"!0x80000001", 0x80000001},  // -denorm
+        {"!0x80800000", 0x80800000},  // -norm
+        {"-2.5", 0xc0200000},
+        {"!0xff800000", 0xff800000},  // -inf
+        {"!0xff800001", 0xff800001},  // NaN
+    }));
 
 }  // anonymous namespace