From 453b54856ea9b0de377a71f70c84530eb930d104 Mon Sep 17 00:00:00 2001
From: Patrick Pelissier <patrick.pelissier@gmail.com>
Date: Sun, 12 Nov 2017 09:41:10 +0100
Subject: [PATCH] Move CLZ from genint to core

---
 m-core.h   | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 m-genint.h | 49 -------------------------------------------------
 2 files changed, 50 insertions(+), 49 deletions(-)

diff --git a/m-core.h b/m-core.h
index 801dd5ff..42437bb0 100644
--- a/m-core.h
+++ b/m-core.h
@@ -1252,6 +1252,56 @@ static inline uint64_t m_core_roundpow2(uint64_t v)
   return v;
 }
 
+/* Return the count leading zero of the argument */
+#if defined(__GNUC__) && (__GNUC__*100 + __GNUC_MINOR__) >= 304
+static inline unsigned int m_core_clz(unsigned long limb)
+{
+  return M_UNLIKELY (limb == 0) ? sizeof(unsigned long)*CHAR_BIT : __builtin_clzl(limb);
+}
+#else
+#define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
+
+static inline unsigned int m_core_clz(unsigned long limb)
+{
+  unsigned int shift = 0;
+  /* This code should be branchless on most targets */
+#if ULONG_MAX == 18446744073709551615UL
+  /* Compute shift so that, it is
+     + -7 if the highest 56 bits are clear,
+     + -6 for the highest 48 bits,
+     + -5 for the highest 40 bits,
+     + -4 for the highest 32 bits,
+     + -3 for the highest 24 bits,
+     + -2 for the highest 16 bits,
+     + -1 for the highest 8 bits,
+     + 0 otherwise */
+  shift = -(limb < 0x100000000000000UL);
+  shift -= (limb < 0x1000000000000UL);
+  shift -= (limb < 0x10000000000UL);
+  shift -= (limb < 0x100000000UL);
+  shift -= (limb < 0x1000000UL);
+  shift -= (limb < 0x10000UL);
+  shift -= (limb < 0x100UL);
+  shift  = shift*8 + 56;
+  shift = 56 - shift + M_CORE_CLZ_TAB[limb >> shift ];
+#elif ULONG_MAX == 4294967295UL
+  /* Compute shift so that, it is
+     + -3 if the highest 24 bits are clear,
+     + -2 for the highest 16 bits,
+     + -1 for the highest 8 bits,
+     + 0 otherwise */
+  shift = -(limb < 0x1000000UL);
+  shift -= (limb < 0x10000UL);
+  shift -= (limb < 0x100UL);
+  shift  = shift*8 + 24;
+  shift = 24 - shift + M_CORE_CLZ_TAB[limb >> shift ];
+#else
+# error Unkown size for unsigned long. Please create a bug report and report the ULONG_MAX value.
+#endif
+  return shift;
+}
+#endif
+
 /* Implement a kind of FNV1A Hash.
    Inspired by http://www.sanmayce.com/Fastest_Hash/ Jesteress and port to 64 bits.
    See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash
diff --git a/m-genint.h b/m-genint.h
index b7922461..3c7c6f21 100644
--- a/m-genint.h
+++ b/m-genint.h
@@ -76,55 +76,6 @@ static inline void genint_clear(genint_t s)
   s->data = NULL;
 }
 
-#if defined(__GNUC__) && (__GNUC__*100 + __GNUC_MINOR__) >= 304
-static inline unsigned int m_core_clz(unsigned long limb)
-{
-  return M_UNLIKELY (limb == 0) ? sizeof(unsigned long)*CHAR_BIT : __builtin_clzl(limb);
-}
-#else
-#define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
-
-static inline unsigned int m_core_clz(unsigned long limb)
-{
-  unsigned int shift = 0;
-  /* This code should be branchless on most targets */
-#if ULONG_MAX == 18446744073709551615UL
-  /* Compute shift so that, it is
-     + -7 if the highest 56 bits are clear,
-     + -6 for the highest 48 bits,
-     + -5 for the highest 40 bits,
-     + -4 for the highest 32 bits,
-     + -3 for the highest 24 bits,
-     + -2 for the highest 16 bits,
-     + -1 for the highest 8 bits,
-     + 0 otherwise */
-  shift = -(limb < 0x100000000000000UL);
-  shift -= (limb < 0x1000000000000UL);
-  shift -= (limb < 0x10000000000UL);
-  shift -= (limb < 0x100000000UL);
-  shift -= (limb < 0x1000000UL);
-  shift -= (limb < 0x10000UL);
-  shift -= (limb < 0x100UL);
-  shift  = shift*8 + 56;
-  shift = 56 - shift + M_CORE_CLZ_TAB[limb >> shift ];
-#elif ULONG_MAX == 4294967295UL
-  /* Compute shift so that, it is
-     + -3 if the highest 24 bits are clear,
-     + -2 for the highest 16 bits,
-     + -1 for the highest 8 bits,
-     + 0 otherwise */
-  shift = -(limb < 0x1000000UL);
-  shift -= (limb < 0x10000UL);
-  shift -= (limb < 0x100UL);
-  shift  = shift*8 + 24;
-  shift = 24 - shift + M_CORE_CLZ_TAB[limb >> shift ];
-#else
-# error Unkown size for unsigned long. Please create a bug report and report the ULONG_MAX value.
-#endif
-  return shift;
-}
-#endif
-
 static inline size_t genint_pop(genint_t s)
 {
   GENINT_CONTRACT(s);