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BPMemory: Eliminate union type punning

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This is undefined behavior in C++.
This commit is contained in:
Lioncash 2017-01-23 15:48:14 -05:00
parent 98311cd9f4
commit 1f596a23af
2 changed files with 26 additions and 22 deletions
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24
Source/Core/VideoCommon/BPMemory.cpp
View File

@ -4,6 +4,30 @@
#include "VideoCommon/BPMemory.h"
#include <cstring>
// BP state
// STATE_TO_SAVE
BPMemory bpmem;
float FogParam0::GetA() const
{
// scale mantissa from 11 to 23 bits
const u32 integral = (static_cast<u32>(sign) << 31) | (static_cast<u32>(exponent) << 23) |
(static_cast<u32>(mantissa) << 12);
float real;
std::memcpy(&real, &integral, sizeof(u32));
return real;
}
float FogParam3::GetC() const
{
// scale mantissa from 11 to 23 bits
const u32 integral = (static_cast<u32>(c_sign) << 31) | (static_cast<u32>(c_exp) << 23) |
(static_cast<u32>(c_mant) << 12);
float real;
std::memcpy(&real, &integral, sizeof(u32));
return real;
}

24
Source/Core/VideoCommon/BPMemory.h
View File

@ -674,17 +674,7 @@ union FogParam0
u32 sign : 1;
};
float GetA()
{
union
{
u32 i;
float f;
} dummy;
dummy.i = ((u32)sign << 31) | ((u32)exponent << 23) |
((u32)mantissa << 12); // scale mantissa from 11 to 23 bits
return dummy.f;
}
float GetA() const;
u32 hex;
};
@ -701,17 +691,7 @@ union FogParam3
};
// amount to subtract from eyespacez after range adjustment
float GetC()
{
union
{
u32 i;
float f;
} dummy;
dummy.i = ((u32)c_sign << 31) | ((u32)c_exp << 23) |
((u32)c_mant << 12); // scale mantissa from 11 to 23 bits
return dummy.f;
}
float GetC() const;
u32 hex;
};