From 2623fec1cdd5fd9b15ee67c4b115385c67129ef4 Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Fri, 28 Apr 2017 14:15:31 +0800
Subject: [PATCH] include/intarith: templatize ctz/clz/cbits helpers

Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 src/include/denc.h            |  2 +-
 src/include/intarith.h        | 66 ++++++++++++++++++++++++++++++-----
 src/os/bluestore/BlueStore.cc |  2 +-
 3 files changed, 59 insertions(+), 11 deletions(-)

diff --git a/src/include/denc.h b/src/include/denc.h
index 97b4713ce5e..e3a8f29e265 100644
--- a/src/include/denc.h
+++ b/src/include/denc.h
@@ -344,7 +344,7 @@ inline void denc_signed_varint_lowz(int64_t v,
     v = -v;
     negative = true;
   }
-  int lowznib = v ? (ctz(v) / 4) : 0;
+  unsigned lowznib = v ? (ctz(v) / 4) : 0u;
   if (lowznib > 3)
     lowznib = 3;
   v >>= lowznib * 4;
diff --git a/src/include/intarith.h b/src/include/intarith.h
index f46a1eb2fe2..390cdc024d7 100644
--- a/src/include/intarith.h
+++ b/src/include/intarith.h
@@ -78,17 +78,33 @@
 
 // count trailing zeros.
 // NOTE: the builtin is nondeterministic on 0 input
-static inline unsigned ctz(unsigned v) {
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) <= sizeof(unsigned)),
+  unsigned>::type ctz(T v) {
   if (v == 0)
     return sizeof(v) * 8;
   return __builtin_ctz(v);
 }
-static inline unsigned ctzl(unsigned long v) {
+
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) > sizeof(unsigned int) &&
+   sizeof(T) <= sizeof(unsigned long)),
+  unsigned>::type ctz(T v) {
   if (v == 0)
     return sizeof(v) * 8;
   return __builtin_ctzl(v);
 }
-static inline unsigned ctzll(unsigned long long v) {
+
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) > sizeof(unsigned long) &&
+   sizeof(T) <= sizeof(unsigned long long)),
+  unsigned>::type ctz(T v) {
   if (v == 0)
     return sizeof(v) * 8;
   return __builtin_ctzll(v);
@@ -96,34 +112,66 @@ static inline unsigned ctzll(unsigned long long v) {
 
 // count leading zeros
 // NOTE: the builtin is nondeterministic on 0 input
-static inline unsigned clz(unsigned v) {
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) <= sizeof(unsigned)),
+  unsigned>::type clz(T v) {
   if (v == 0)
     return sizeof(v) * 8;
   return __builtin_clz(v);
 }
-static inline unsigned clzl(unsigned long v) {
+
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) > sizeof(unsigned int) &&
+   sizeof(T) <= sizeof(unsigned long)),
+  unsigned>::type clz(T v) {
   if (v == 0)
     return sizeof(v) * 8;
   return __builtin_clzl(v);
 }
-static inline unsigned clzll(unsigned long long v) {
+
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) > sizeof(unsigned long) &&
+   sizeof(T) <= sizeof(unsigned long long)),
+  unsigned>::type clz(T v) {
   if (v == 0)
     return sizeof(v) * 8;
   return __builtin_clzll(v);
 }
 
 // count bits (set + any 0's that follow)
-static inline unsigned cbits(unsigned v) {
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) <= sizeof(unsigned)),
+  unsigned>::type cbits(T v) {
   if (v == 0)
     return 0;
   return (sizeof(v) * 8) - __builtin_clz(v);
 }
-static inline unsigned cbitsl(unsigned long v) {
+
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) > sizeof(unsigned int) &&
+   sizeof(T) <= sizeof(unsigned long)),
+  unsigned>::type cbits(T v) {
   if (v == 0)
     return 0;
   return (sizeof(v) * 8) - __builtin_clzl(v);
 }
-static inline unsigned cbitsll(unsigned long long v) {
+
+template<class T>
+  inline typename std::enable_if<
+  (std::is_integral<T>::value &&
+   sizeof(T) > sizeof(unsigned long) &&
+   sizeof(T) <= sizeof(unsigned long long)),
+  unsigned>::type cbits(T v) {
   if (v == 0)
     return 0;
   return (sizeof(v) * 8) - __builtin_clzll(v);
diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index b08a7bcab8e..a87422bd92d 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -9661,7 +9661,7 @@ int BlueStore::_do_write(
     auto order = min_alloc_size_order.load();
     if (o->onode.expected_write_size) {
       wctx.csum_order = std::max(order,
-			         (size_t)ctzl(o->onode.expected_write_size));
+			         (uint8_t)ctz(o->onode.expected_write_size));
     } else {
       wctx.csum_order = order;
     }
-- 
2.39.5