From 383f3a3a20ff7268b4c2fad14d0e20f266682b77 Mon Sep 17 00:00:00 2001
From: vesslanjin <jun.i.jin@intel.com>
Date: Fri, 8 Oct 2021 09:19:58 -0400
Subject: [PATCH] =?UTF-8?q?Remove=C2=A0branchy=C2=A0code=C2=A0in=C2=A0filt?=
 =?UTF-8?q?er=C2=A0operation=C2=A0with=C2=A0a=C2=A0better=C2=A0implementat?=
 =?UTF-8?q?ion=C2=A0with=C2=A0popcnt/ctz=C2=A0which=C2=A0have=C2=A0better?=
 =?UTF-8?q?=C2=A0performance?=
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Content-Transfer-Encoding: 8bit

Co-authored-by: Zhu Jasper <jasper.zhu@intel.com>
---
 src/Columns/ColumnFixedString.cpp | 22 +++++++++-------------
 src/Columns/ColumnVector.cpp      | 11 +++++++----
 src/Columns/ColumnsCommon.cpp     | 11 +++++++----
 3 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/src/Columns/ColumnFixedString.cpp b/src/Columns/ColumnFixedString.cpp
index ce39ab0994c..4bfc6513263 100644
--- a/src/Columns/ColumnFixedString.cpp
+++ b/src/Columns/ColumnFixedString.cpp
@@ -231,7 +231,7 @@ ColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t result
     const UInt8 * filt_end = filt_pos + col_size;
     const UInt8 * data_pos = chars.data();
 
-#ifdef __SSE2__
+#if defined(__SSE2__) && defined(__POPCNT__)
     /** A slightly more optimized version.
         * Based on the assumption that often pieces of consecutive values
         *  completely pass or do not pass the filter.
@@ -251,28 +251,24 @@ ColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t result
         if (0 == mask)
         {
             /// Nothing is inserted.
-            data_pos += chars_per_simd_elements;
         }
         else if (0xFFFF == mask)
         {
             res->chars.insert(data_pos, data_pos + chars_per_simd_elements);
-            data_pos += chars_per_simd_elements;
         }
         else
         {
             size_t res_chars_size = res->chars.size();
-            for (size_t i = 0; i < SIMD_BYTES; ++i)
-            {
-                if (filt_pos[i])
-                {
-                    res->chars.resize(res_chars_size + n);
-                    memcpySmallAllowReadWriteOverflow15(&res->chars[res_chars_size], data_pos, n);
-                    res_chars_size += n;
-                }
-                data_pos += n;
+            size_t pcnt = __builtin_popcount(mask);
+            for(size_t j = 0; j < pcnt; j++) {
+                size_t index = __builtin_ctz(mask);
+                res->chars.resize(res_chars_size + n);
+                memcpySmallAllowReadWriteOverflow15(&res->chars[res_chars_size], data_pos+index*n, n);
+                res_chars_size += n;
+                mask = mask & (mask-1);
             }
         }
-
+        data_pos += chars_per_simd_elements;
         filt_pos += SIMD_BYTES;
     }
 #endif
diff --git a/src/Columns/ColumnVector.cpp b/src/Columns/ColumnVector.cpp
index 7f3cdaeec7f..ff84204a7cb 100644
--- a/src/Columns/ColumnVector.cpp
+++ b/src/Columns/ColumnVector.cpp
@@ -311,7 +311,7 @@ ColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t result_s
     const UInt8 * filt_end = filt_pos + size;
     const T * data_pos = data.data();
 
-#ifdef __SSE2__
+#if defined(__SSE2__) && defined(__POPCNT__)
     /** A slightly more optimized version.
     * Based on the assumption that often pieces of consecutive values
     *  completely pass or do not pass the filter.
@@ -337,9 +337,12 @@ ColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t result_s
         }
         else
         {
-            for (size_t i = 0; i < SIMD_BYTES; ++i)
-                if (filt_pos[i])
-                    res_data.push_back(data_pos[i]);
+            size_t pcnt = __builtin_popcount(mask);
+            for(size_t j = 0; j < pcnt; j++) {
+                size_t index = __builtin_ctz(mask);
+                res_data.push_back(data_pos[index]);
+                mask = mask & (mask-1);
+            }         
         }
 
         filt_pos += SIMD_BYTES;
diff --git a/src/Columns/ColumnsCommon.cpp b/src/Columns/ColumnsCommon.cpp
index 41933ed08ed..5c0214054b2 100644
--- a/src/Columns/ColumnsCommon.cpp
+++ b/src/Columns/ColumnsCommon.cpp
@@ -229,7 +229,7 @@ namespace
             memcpy(&res_elems[elems_size_old], &src_elems[arr_offset], arr_size * sizeof(T));
         };
 
-    #ifdef __SSE2__
+    #if defined(__SSE2__) && defined(__POPCNT__)
         const __m128i zero_vec = _mm_setzero_si128();
         static constexpr size_t SIMD_BYTES = 16;
         const auto * filt_end_aligned = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
@@ -262,9 +262,12 @@ namespace
             }
             else
             {
-                for (size_t i = 0; i < SIMD_BYTES; ++i)
-                    if (filt_pos[i])
-                        copy_array(offsets_pos + i);
+                size_t pcnt = __builtin_popcount(mask);
+                for(size_t j = 0; j < pcnt; j++) {
+                    size_t index = __builtin_ctz(mask);
+                    copy_array(offsets_pos + index);
+                    mask = mask & (mask-1);
+                }
             }
 
             filt_pos += SIMD_BYTES;