From df0d52f4bd78c2197a88a805a1dd402978df3290 Mon Sep 17 00:00:00 2001
From: David Robillard <d@drobilla.net>
Date: Sat, 11 Aug 2018 19:50:27 +0200
Subject: Use calloc to ensure racks are zero initialized with low overhead

---
 chilbert/BigBitVec.hpp | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

(limited to 'chilbert')

diff --git a/chilbert/BigBitVec.hpp b/chilbert/BigBitVec.hpp
index 79c8151..8b315a0 100644
--- a/chilbert/BigBitVec.hpp
+++ b/chilbert/BigBitVec.hpp
@@ -23,6 +23,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cstdlib>
 #include <cstring>
 #include <memory>
 
@@ -40,13 +41,13 @@ class CBigBitVec
 {
 public:
 	CBigBitVec(const int bits = 0)
-	  : m_pcRacks{new FBV_UINT[bits == 0 ? 0 : FBVS_NEEDED(bits)]}
+	  : m_pcRacks{make_racks(FBVS_NEEDED(bits))}
 	  , m_iRacks{bits == 0 ? 0 : FBVS_NEEDED(bits)}
 	{
 	}
 
 	CBigBitVec(const CBigBitVec& vec)
-	  : m_pcRacks{new FBV_UINT[vec.m_iRacks]}
+	  : m_pcRacks{make_racks(vec.m_iRacks)}
 	  , m_iRacks{vec.m_iRacks}
 	{
 		if (vec.m_pcRacks) {
@@ -59,7 +60,7 @@ public:
 	CBigBitVec(CBigBitVec&& vec) = default;
 
 	CBigBitVec(const CFixBitVec& vec)
-	  : m_pcRacks{new FBV_UINT[1]}
+	  : m_pcRacks{make_racks(1)}
 	  , m_iRacks{1}
 	{
 		m_pcRacks[0] = vec.rack();
@@ -116,7 +117,7 @@ public:
 	{
 		if (m_iRacks < vec.m_iRacks) {
 			m_iRacks  = vec.m_iRacks;
-			m_pcRacks = std::unique_ptr<FBV_UINT[]>{new FBV_UINT[m_iRacks]};
+			m_pcRacks = make_racks(m_iRacks);
 			memcpy(m_pcRacks.get(),
 			       vec.m_pcRacks.get(),
 			       sizeof(CFixBitVec) * m_iRacks);
@@ -138,7 +139,7 @@ public:
 	CBigBitVec& operator=(const CFixBitVec& vec)
 	{
 		if (!m_pcRacks) {
-			m_pcRacks = std::unique_ptr<FBV_UINT[]>{new FBV_UINT[1]};
+			m_pcRacks = make_racks(1);
 		}
 
 		m_iRacks     = 1;
@@ -149,7 +150,7 @@ public:
 	CBigBitVec& operator=(const FBV_UINT j)
 	{
 		if (!m_pcRacks) {
-			m_pcRacks = std::unique_ptr<FBV_UINT[]>{new FBV_UINT[1]};
+			m_pcRacks = make_racks(1);
 		}
 
 		m_iRacks     = 1;
@@ -464,6 +465,18 @@ private:
 		int bit;
 	};
 
+	struct RacksDeleter
+	{
+		void operator()(FBV_UINT* const racks) { free(racks); }
+	};
+
+	using RacksPtr = std::unique_ptr<FBV_UINT[], RacksDeleter>;
+
+	static RacksPtr make_racks(const int n)
+	{
+		return RacksPtr{static_cast<FBV_UINT*>(calloc(n, sizeof(FBV_UINT)))};
+	}
+
 	// Right rotates entire racks (in place).
 	void rackRotr(int k)
 	{
@@ -491,8 +504,8 @@ private:
 		}
 	}
 
-	std::unique_ptr<FBV_UINT[]> m_pcRacks;
-	int                         m_iRacks;
+	RacksPtr m_pcRacks;
+	int      m_iRacks;
 };
 
 template <>
-- 
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