30 lines
		
	
	
		
			637 B
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			30 lines
		
	
	
		
			637 B
		
	
	
	
		
			C++
		
	
	
	
| //===-- Support/MathExtras.h - Useful math functions -------------*- C++ -*--=//
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| //
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| // This file contains some functions that are useful for math stuff.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #ifndef SUPPORT_MATH_EXTRAS_H
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| #define SUPPORT_MATH_EXTRAS_H
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| 
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| #include <Support/DataTypes.h>
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| 
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| inline unsigned log2(uint64_t C) {
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|   unsigned getPow;
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|   for (getPow = 0; C > 1; ++getPow)
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|     C >>= 1;
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|   return getPow;
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| }
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| 
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| inline bool isPowerOf2(int64_t C, unsigned &getPow) {
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|   if (C < 0) C = -C;
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|   if (C > 0 && C == (C & ~(C - 1))) {
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|     getPow = log2(C);
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|     return true;
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|   }
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| 
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|   return false;
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| }
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| 
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| #endif
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