Hack representation inference to assume current behavior of float32 loads and stores, which include…

test/cctest/compiler/test-run-properties.cc

Index: test/cctest/compiler/test-run-properties.cc
diff --git a/test/cctest/compiler/test-run-properties.cc b/test/cctest/compiler/test-run-properties.cc
index b1f04c51c2860d75927234b76e0896d04b9bd718..d4442f7a85d6ddfc6f295b3c9e8ba1e087bd350d 100644
--- a/test/cctest/compiler/test-run-properties.cc
+++ b/test/cctest/compiler/test-run-properties.cc
@@ -47,9 +47,10 @@ static void TypedArrayLoadHelper(const char* array_type) {
       CompilationInfo::kContextSpecializing | CompilationInfo::kTypingEnabled);
   for (size_t i = 0; i < arraysize(kValues); ++i) {
     for (size_t j = 0; j < arraysize(kValues); ++j) {
-      double value_a = static_cast<U>(kValues[i]);
-      double value_b = static_cast<U>(kValues[j]);
-      double expected = value_a + value_b;
+      volatile U value_a = static_cast<U>(kValues[i]);

[Michael Starzinger, 2014/09/18 18:38:07]

Man, do I love C++ intuitiveness. :)

+      volatile U value_b = static_cast<U>(kValues[j]);
+      double expected =
+          static_cast<double>(value_a) + static_cast<double>(value_b);

[Sven Panne, 2014/09/19 06:07:26]

Casting away volatile leads to undefined behavior:

Section 7.1.6.1 The cv-qualifiers
... If an attempt is made to refer to an object defined with a
volatile-qualified type through the use of a glvalue
with a non-volatile-qualified type, the program behavior is undefined.

Why was it introduced here at all? Trying to avoid some compiler optimizations?
If that was the intention, that won't work in general.

       T.CheckCall(T.Val(expected), T.Val(static_cast<double>(i)),
                   T.Val(static_cast<double>(j)));
     }
@@ -65,8 +66,8 @@ TEST(TypedArrayLoad) {
   TypedArrayLoadHelper<uint16_t>("Uint16");
   TypedArrayLoadHelper<int32_t>("Int32");
   TypedArrayLoadHelper<uint32_t>("Uint32");
+  TypedArrayLoadHelper<float>("Float32");
   TypedArrayLoadHelper<double>("Float64");
-  // TODO(mstarzinger): Add tests for Float32.
   // TODO(mstarzinger): Add tests for ClampedUint8.
 }
 
@@ -115,9 +116,10 @@ static void TypedArrayStoreHelper(const char* array_type) {
       CompilationInfo::kContextSpecializing | CompilationInfo::kTypingEnabled);
   for (size_t i = 0; i < arraysize(kValues); ++i) {
     for (size_t j = 0; j < arraysize(kValues); ++j) {
-      double value_a = static_cast<U>(kValues[i]);
-      double value_b = static_cast<U>(kValues[j]);
-      double expected = value_b + value_a;
+      volatile U value_a = static_cast<U>(kValues[i]);
+      volatile U value_b = static_cast<U>(kValues[j]);
+      double expected =
+          static_cast<double>(value_a) + static_cast<double>(value_b);
       T.CheckCall(T.Val(expected), T.Val(static_cast<double>(i)),
                   T.Val(static_cast<double>(j)));
     }
@@ -133,7 +135,7 @@ TEST(TypedArrayStore) {
   TypedArrayStoreHelper<uint16_t>("Uint16");
   TypedArrayStoreHelper<int32_t>("Int32");
   TypedArrayStoreHelper<uint32_t>("Uint32");
+  TypedArrayStoreHelper<float>("Float32");
   TypedArrayStoreHelper<double>("Float64");
-  // TODO(mstarzinger): Add tests for Float32.
   // TODO(mstarzinger): Add tests for ClampedUint8.
 }