Saturated arithmetic changed to use templates to fix build-issues

Source/wtf/SaturatedArithmetic.h

 /*
  * Copyright (c) 2012, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 68 matching lines @@
     // the ARM asm version, see SaturatedArithmetiARM.h for the equivalent asm
     // version.
     return std::numeric_limits<int>::max();
 }
 
 inline int getMinSaturatedSetResultForTesting(int FractionalShift)
 {
     return std::numeric_limits<int>::min();
 }
 
-ALWAYS_INLINE int saturatedSet(int value, int FractionalShift)
+template<size_t saturate, size_t fractionalShift>

[Sami, 2014/07/09 13:59:26]

Could you not calculate |saturate| from |fractionalShift| or do both need to be
separate constants that come from the expansion site?

[picksi, 2014/07/09 14:27:52]

In the previous version I did exactly this, but with android_full_debug=1 in
chromium.gyp_env it refused to work. I could only get it to compile when both
parameters came into the function as templated-parameters.

The "saturate" parameter is not actually needed by the C++ version and is only
here to create a common interface for the C++ and ARM version, so the calling
code can remain implementation agnostic.

+ALWAYS_INLINE int saturatedSetSigned(int value)
 {
+    // This function is implemented as a template to make a common interface
+    // for this and the ARM version, which will only compile under all compilers
+    // if it is implemented as a template specialized with constants.
+
     const int intMaxForLayoutUnit =
-        std::numeric_limits<int>::max() >> FractionalShift;
+        std::numeric_limits<int>::max() >> fractionalShift;
 
     const int intMinForLayoutUnit =
-        std::numeric_limits<int>::min() >> FractionalShift;
+        std::numeric_limits<int>::min() >> fractionalShift;
 
     if (value > intMaxForLayoutUnit)
         return std::numeric_limits<int>::max();
 
     if (value < intMinForLayoutUnit)
         return std::numeric_limits<int>::min();
 
-    return value << FractionalShift;
+    return value << fractionalShift;
 }
 
+template<size_t saturate, size_t fractionalShift>
+ALWAYS_INLINE int saturatedSetUnsigned(unsigned value)
+{
+    // This function is implemented as a template to make a common interface
+    // for this and the ARM version, which will only compile under all compilers
+    // if it is implemented as a template specialized with constants.
 
-ALWAYS_INLINE int saturatedSet(unsigned value, int FractionalShift)
-{
     const unsigned intMaxForLayoutUnit =
-        std::numeric_limits<int>::max() >> FractionalShift;
+        std::numeric_limits<int>::max() >> fractionalShift;
 
     if (value >= intMaxForLayoutUnit)
         return std::numeric_limits<int>::max();
 
-    return value << FractionalShift;
+    return value << fractionalShift;
 }
 
 #endif // CPU(ARM) && COMPILER(GCC)
 #endif // SaturatedArithmetic_h