From 9c066e964d2d3a2abd07e99d1406e8b2d975d909 Mon Sep 17 00:00:00 2001
From: Robert Schulze <robert@clickhouse.com>
Date: Fri, 4 Nov 2022 15:52:48 +0000
Subject: [PATCH] Less use of CH-specific bit_cast()

Converted usage of CH-custom bit_cast to std::bit_cast if possible, i.e.
when
  sizeof(From) == sizeof(To).
(The CH-custom bit_cast is able to deal with sizeof(From) != sizeof(To).)

Motivation for this came from #42847 where it is not clear how the
internal bit_cast should behave on big endian systems, so we better
avoid that situation as much as possible.
---
 programs/library-bridge/ExternalDictionaryLibraryHandler.cpp | 3 +--
 programs/library-bridge/ExternalDictionaryLibraryUtils.h     | 1 -
 programs/obfuscator/Obfuscator.cpp                           | 5 ++---
 src/AggregateFunctions/QuantileBFloat16Histogram.h           | 5 ++---
 src/Databases/MySQL/MaterializedMySQLSyncThread.cpp          | 1 -
 src/Functions/FunctionsRound.h                               | 1 -
 src/Functions/isFinite.cpp                                   | 5 ++---
 src/Functions/isInfinite.cpp                                 | 5 ++---
 src/Functions/padString.cpp                                  | 5 ++---
 src/Interpreters/BloomFilterHash.h                           | 1 -
 .../MergeTree/MergeTreeIndexAggregatorBloomFilter.cpp        | 1 -
 src/Storages/MergeTree/MergeTreeIndexBloomFilter.cpp         | 1 -
 src/Storages/MergeTree/MergeTreeIndexGranuleBloomFilter.cpp  | 1 -
 13 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/programs/library-bridge/ExternalDictionaryLibraryHandler.cpp b/programs/library-bridge/ExternalDictionaryLibraryHandler.cpp
index 14850da2ebf..c60d4a4e5cc 100644
--- a/programs/library-bridge/ExternalDictionaryLibraryHandler.cpp
+++ b/programs/library-bridge/ExternalDictionaryLibraryHandler.cpp
@@ -1,7 +1,6 @@
 #include "ExternalDictionaryLibraryHandler.h"
 
 #include <base/scope_guard.h>
-#include <base/bit_cast.h>
 #include <base/find_symbols.h>
 #include <IO/ReadHelpers.h>
 
@@ -113,7 +112,7 @@ Block ExternalDictionaryLibraryHandler::loadAll()
 
 Block ExternalDictionaryLibraryHandler::loadIds(const std::vector<uint64_t> & ids)
 {
-    const ExternalDictionaryLibraryAPI::VectorUInt64 ids_data{bit_cast<decltype(ExternalDictionaryLibraryAPI::VectorUInt64::data)>(ids.data()), ids.size()};
+    const ExternalDictionaryLibraryAPI::VectorUInt64 ids_data{std::bit_cast<decltype(ExternalDictionaryLibraryAPI::VectorUInt64::data)>(ids.data()), ids.size()};
 
     auto columns_holder = std::make_unique<ExternalDictionaryLibraryAPI::CString[]>(attributes_names.size());
     ExternalDictionaryLibraryAPI::CStrings columns_pass{static_cast<decltype(ExternalDictionaryLibraryAPI::CStrings::data)>(columns_holder.get()), attributes_names.size()};
diff --git a/programs/library-bridge/ExternalDictionaryLibraryUtils.h b/programs/library-bridge/ExternalDictionaryLibraryUtils.h
index e813efab2a6..c9d03d27f75 100644
--- a/programs/library-bridge/ExternalDictionaryLibraryUtils.h
+++ b/programs/library-bridge/ExternalDictionaryLibraryUtils.h
@@ -2,7 +2,6 @@
 
 #include <Common/StringUtils/StringUtils.h>
 #include <Core/Block.h>
-#include <base/bit_cast.h>
 #include <base/range.h>
 
 #include "ExternalDictionaryLibraryAPI.h"
diff --git a/programs/obfuscator/Obfuscator.cpp b/programs/obfuscator/Obfuscator.cpp
index 7fdc5a54d8a..b6952ad6cb0 100644
--- a/programs/obfuscator/Obfuscator.cpp
+++ b/programs/obfuscator/Obfuscator.cpp
@@ -32,7 +32,6 @@
 #include <Core/Block.h>
 #include <base/StringRef.h>
 #include <Common/DateLUT.h>
-#include <base/bit_cast.h>
 #include <IO/ReadBufferFromFileDescriptor.h>
 #include <IO/WriteBufferFromFileDescriptor.h>
 #include <IO/ReadBufferFromFile.h>
@@ -278,9 +277,9 @@ Float transformFloatMantissa(Float x, UInt64 seed)
     using UInt = std::conditional_t<std::is_same_v<Float, Float32>, UInt32, UInt64>;
     constexpr size_t mantissa_num_bits = std::is_same_v<Float, Float32> ? 23 : 52;
 
-    UInt x_uint = bit_cast<UInt>(x);
+    UInt x_uint = std::bit_cast<UInt>(x);
     x_uint = static_cast<UInt>(feistelNetwork(x_uint, mantissa_num_bits, seed));
-    return bit_cast<Float>(x_uint);
+    return std::bit_cast<Float>(x_uint);
 }
 
 
diff --git a/src/AggregateFunctions/QuantileBFloat16Histogram.h b/src/AggregateFunctions/QuantileBFloat16Histogram.h
index 8ec325e238d..de9f61e01a2 100644
--- a/src/AggregateFunctions/QuantileBFloat16Histogram.h
+++ b/src/AggregateFunctions/QuantileBFloat16Histogram.h
@@ -1,7 +1,6 @@
 #pragma once
 
 #include <base/types.h>
-#include <base/bit_cast.h>
 #include <base/sort.h>
 #include <Common/HashTable/HashMap.h>
 
@@ -104,13 +103,13 @@ private:
     /// Take the most significant 16 bits of the floating point number.
     BFloat16 toBFloat16(const Value & x) const
     {
-        return bit_cast<UInt32>(static_cast<Float32>(x)) >> 16;
+        return std::bit_cast<UInt32>(static_cast<Float32>(x)) >> 16;
     }
 
     /// Put the bits into most significant 16 bits of the floating point number and fill other bits with zeros.
     Float32 toFloat32(const BFloat16 & x) const
     {
-        return bit_cast<Float32>(x << 16);
+        return std::bit_cast<Float32>(x << 16);
     }
 
     using Pair = PairNoInit<Float32, Weight>;
diff --git a/src/Databases/MySQL/MaterializedMySQLSyncThread.cpp b/src/Databases/MySQL/MaterializedMySQLSyncThread.cpp
index ed9199a359f..29f5719e3ed 100644
--- a/src/Databases/MySQL/MaterializedMySQLSyncThread.cpp
+++ b/src/Databases/MySQL/MaterializedMySQLSyncThread.cpp
@@ -24,7 +24,6 @@
 #include <Common/quoteString.h>
 #include <Common/setThreadName.h>
 #include <base/sleep.h>
-#include <base/bit_cast.h>
 #include <boost/algorithm/string/split.hpp>
 #include <boost/algorithm/string/trim.hpp>
 #include <Parsers/CommonParsers.h>
diff --git a/src/Functions/FunctionsRound.h b/src/Functions/FunctionsRound.h
index 283f1ea5a43..2c7883cf471 100644
--- a/src/Functions/FunctionsRound.h
+++ b/src/Functions/FunctionsRound.h
@@ -16,7 +16,6 @@
 #include <cmath>
 #include <type_traits>
 #include <array>
-#include <base/bit_cast.h>
 #include <base/sort.h>
 #include <algorithm>
 
diff --git a/src/Functions/isFinite.cpp b/src/Functions/isFinite.cpp
index 90185b64fff..612e7067bf5 100644
--- a/src/Functions/isFinite.cpp
+++ b/src/Functions/isFinite.cpp
@@ -1,6 +1,5 @@
 #include <Functions/FunctionNumericPredicate.h>
 #include <Functions/FunctionFactory.h>
-#include <base/bit_cast.h>
 #include <type_traits>
 
 
@@ -20,11 +19,11 @@ struct IsFiniteImpl
     static bool execute(const T t)
     {
         if constexpr (std::is_same_v<T, float>)
-            return (bit_cast<uint32_t>(t)
+            return (std::bit_cast<uint32_t>(t)
                  & 0b01111111100000000000000000000000)
                 != 0b01111111100000000000000000000000;
         else if constexpr (std::is_same_v<T, double>)
-            return (bit_cast<uint64_t>(t)
+            return (std::bit_cast<uint64_t>(t)
                  & 0b0111111111110000000000000000000000000000000000000000000000000000)
                 != 0b0111111111110000000000000000000000000000000000000000000000000000;
         else
diff --git a/src/Functions/isInfinite.cpp b/src/Functions/isInfinite.cpp
index e923e1461bc..ace2c334873 100644
--- a/src/Functions/isInfinite.cpp
+++ b/src/Functions/isInfinite.cpp
@@ -1,6 +1,5 @@
 #include <Functions/FunctionNumericPredicate.h>
 #include <Functions/FunctionFactory.h>
-#include <base/bit_cast.h>
 #include <type_traits>
 
 
@@ -16,11 +15,11 @@ struct IsInfiniteImpl
     static bool execute(const T t)
     {
         if constexpr (std::is_same_v<T, float>)
-            return (bit_cast<uint32_t>(t)
+            return (std::bit_cast<uint32_t>(t)
                  & 0b01111111111111111111111111111111)
                 == 0b01111111100000000000000000000000;
         else if constexpr (std::is_same_v<T, double>)
-            return (bit_cast<uint64_t>(t)
+            return (std::bit_cast<uint64_t>(t)
                  & 0b0111111111111111111111111111111111111111111111111111111111111111)
                 == 0b0111111111110000000000000000000000000000000000000000000000000000;
         else
diff --git a/src/Functions/padString.cpp b/src/Functions/padString.cpp
index c8ed920755c..486fa328fa0 100644
--- a/src/Functions/padString.cpp
+++ b/src/Functions/padString.cpp
@@ -5,7 +5,6 @@
 #include <Functions/GatherUtils/Algorithms.h>
 #include <Functions/GatherUtils/Sinks.h>
 #include <Functions/GatherUtils/Sources.h>
-#include <base/bit_cast.h>
 
 namespace DB
 {
@@ -59,10 +58,10 @@ namespace
             {
                 if (num_chars <= step)
                 {
-                    writeSlice(StringSource::Slice{bit_cast<const UInt8 *>(pad_string.data()), numCharsToNumBytes(num_chars)}, res_sink);
+                    writeSlice(StringSource::Slice{std::bit_cast<const UInt8 *>(pad_string.data()), numCharsToNumBytes(num_chars)}, res_sink);
                     break;
                 }
-                writeSlice(StringSource::Slice{bit_cast<const UInt8 *>(pad_string.data()), numCharsToNumBytes(step)}, res_sink);
+                writeSlice(StringSource::Slice{std::bit_cast<const UInt8 *>(pad_string.data()), numCharsToNumBytes(step)}, res_sink);
                 num_chars -= step;
             }
         }
diff --git a/src/Interpreters/BloomFilterHash.h b/src/Interpreters/BloomFilterHash.h
index 31532cc888a..b95abbfd770 100644
--- a/src/Interpreters/BloomFilterHash.h
+++ b/src/Interpreters/BloomFilterHash.h
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <base/bit_cast.h>
 #include <Common/HashTable/Hash.h>
 #include <Columns/IColumn.h>
 #include <Columns/ColumnArray.h>
diff --git a/src/Storages/MergeTree/MergeTreeIndexAggregatorBloomFilter.cpp b/src/Storages/MergeTree/MergeTreeIndexAggregatorBloomFilter.cpp
index b19080b5097..9bc0e4e6dc0 100644
--- a/src/Storages/MergeTree/MergeTreeIndexAggregatorBloomFilter.cpp
+++ b/src/Storages/MergeTree/MergeTreeIndexAggregatorBloomFilter.cpp
@@ -1,6 +1,5 @@
 #include <Storages/MergeTree/MergeTreeIndexAggregatorBloomFilter.h>
 
-#include <base/bit_cast.h>
 #include <Columns/ColumnString.h>
 #include <Columns/ColumnsNumber.h>
 #include <Columns/ColumnFixedString.h>
diff --git a/src/Storages/MergeTree/MergeTreeIndexBloomFilter.cpp b/src/Storages/MergeTree/MergeTreeIndexBloomFilter.cpp
index 33668b96a60..c2ed081ac00 100644
--- a/src/Storages/MergeTree/MergeTreeIndexBloomFilter.cpp
+++ b/src/Storages/MergeTree/MergeTreeIndexBloomFilter.cpp
@@ -3,7 +3,6 @@
 #include <Interpreters/TreeRewriter.h>
 #include <Interpreters/ExpressionAnalyzer.h>
 #include <base/types.h>
-#include <base/bit_cast.h>
 #include <DataTypes/DataTypeNullable.h>
 #include <Storages/MergeTree/MergeTreeIndexConditionBloomFilter.h>
 #include <Columns/ColumnConst.h>
diff --git a/src/Storages/MergeTree/MergeTreeIndexGranuleBloomFilter.cpp b/src/Storages/MergeTree/MergeTreeIndexGranuleBloomFilter.cpp
index f80d40d2fa8..7efaf0866db 100644
--- a/src/Storages/MergeTree/MergeTreeIndexGranuleBloomFilter.cpp
+++ b/src/Storages/MergeTree/MergeTreeIndexGranuleBloomFilter.cpp
@@ -5,7 +5,6 @@
 #include <Columns/ColumnFixedString.h>
 #include <DataTypes/DataTypeNullable.h>
 #include <Common/HashTable/Hash.h>
-#include <base/bit_cast.h>
 #include <Interpreters/BloomFilterHash.h>
 #include <IO/WriteHelpers.h>