Rename Log2 and add IsPow2 to MathUtils for future use

Also remove unused pow2/pow2f functions.

Source/Core/Common/MathUtil.h

@@ -166,16 +166,15 @@ struct Rectangle
 
 }  // namespace MathUtil
 
-inline float pow2f(float x) {return x * x;}
-inline double pow2(double x) {return x * x;}
-
 float MathFloatVectorSum(const std::vector<float>&);
 
 #define ROUND_UP(x, a)   (((x) + (a) - 1) & ~((a) - 1))
 #define ROUND_DOWN(x, a) ((x) & ~((a) - 1))
 
+inline bool IsPow2(u32 imm) {return (imm & (imm - 1)) == 0;}
+
 // Rounds down. 0 -> undefined
-inline int Log2(u64 val)
+inline int IntLog2(u64 val)
 {
 #if defined(__GNUC__)
 	return 63 - __builtin_clzll(val);

Source/Core/DolphinWX/GameListCtrl.cpp

@@ -397,7 +397,7 @@ static wxString NiceSizeFormat(u64 _size)
 	// Find largest power of 2 less than _size.
 	// div 10 to get largest named unit less than _size
 	// 10 == log2(1024) (number of B in a KiB, KiB in a MiB, etc)
-	const u64 unit = Log2(std::max<u64>(_size, 1)) / 10;
+	const u64 unit = IntLog2(std::max<u64>(_size, 1)) / 10;
 	const u64 unit_size = (1 << (unit * 10));
 
 	// mul 1000 for 3 decimal places, add 5 to round up, div 10 for 2 decimal places

Source/Core/VideoBackends/OGL/StreamBuffer.cpp

@@ -23,7 +23,7 @@ static u32 genBuffer()
 }
 
 StreamBuffer::StreamBuffer(u32 type, u32 size)
-: m_buffer(genBuffer()), m_buffertype(type), m_size(ROUND_UP_POW2(size)), m_bit_per_slot(Log2(ROUND_UP_POW2(size) / SYNC_POINTS))
+: m_buffer(genBuffer()), m_buffertype(type), m_size(ROUND_UP_POW2(size)), m_bit_per_slot(IntLog2(ROUND_UP_POW2(size) / SYNC_POINTS))
 {
 	m_iterator = 0;
 	m_used_iterator = 0;

Source/Core/VideoCommon/TextureConversionShader.cpp

@@ -91,8 +91,8 @@ static void WriteSwizzler(char*& p, u32 format, API_TYPE ApiType)
 
 	WRITE(p, "  int y_block_position = uv1.y & %d;\n", ~(blkH - 1));
 	WRITE(p, "  int y_offset_in_block = uv1.y & %d;\n", blkH - 1);
-	WRITE(p, "  int x_virtual_position = (uv1.x << %d) + y_offset_in_block * position.z;\n", Log2(samples));
+	WRITE(p, "  int x_virtual_position = (uv1.x << %d) + y_offset_in_block * position.z;\n", IntLog2(samples));
-	WRITE(p, "  int x_block_position = (x_virtual_position >> %d) & %d;\n", Log2(blkH), ~(blkW - 1));
+	WRITE(p, "  int x_block_position = (x_virtual_position >> %d) & %d;\n", IntLog2(blkH), ~(blkW - 1));
 	if (samples == 1)
 	{
 		// 32 bit textures (RGBA8 and Z24) are stored in 2 cache line increments
@@ -100,7 +100,7 @@ static void WriteSwizzler(char*& p, u32 format, API_TYPE ApiType)
 		WRITE(p, "  x_virtual_position = x_virtual_position << 1;\n");
 	}
 	WRITE(p, "  int x_offset_in_block = x_virtual_position & %d;\n", blkW - 1);
-	WRITE(p, "  int y_offset = (x_virtual_position >> %d) & %d;\n", Log2(blkW), blkH - 1);
+	WRITE(p, "  int y_offset = (x_virtual_position >> %d) & %d;\n", IntLog2(blkW), blkH - 1);
 
 	WRITE(p, "  sampleUv.x = x_offset_in_block + x_block_position;\n");
 	WRITE(p, "  sampleUv.y = y_block_position + y_offset;\n");

Source/UnitTests/Common/MathUtilTest.cpp

@@ -44,17 +44,17 @@ TEST(MathUtil, IsSNAN)
 	EXPECT_TRUE(MathUtil::IsSNAN(std::numeric_limits<double>::signaling_NaN()));
 }
 
-TEST(MathUtil, Log2)
+TEST(MathUtil, IntLog2)
 {
-	EXPECT_EQ(0, Log2(1));
+	EXPECT_EQ(0, IntLog2(1));
-	EXPECT_EQ(1, Log2(2));
+	EXPECT_EQ(1, IntLog2(2));
-	EXPECT_EQ(2, Log2(4));
+	EXPECT_EQ(2, IntLog2(4));
-	EXPECT_EQ(3, Log2(8));
+	EXPECT_EQ(3, IntLog2(8));
-	EXPECT_EQ(63, Log2(0x8000000000000000ull));
+	EXPECT_EQ(63, IntLog2(0x8000000000000000ull));
 
 	// Rounding behavior.
-	EXPECT_EQ(3, Log2(15));
+	EXPECT_EQ(3, IntLog2(15));
-	EXPECT_EQ(63, Log2(0xFFFFFFFFFFFFFFFFull));
+	EXPECT_EQ(63, IntLog2(0xFFFFFFFFFFFFFFFFull));
 }
 
 TEST(MathUtil, FlushToZero)