Revert IPS4O sort to std::sort for now. We'll switch to IPS4O in another PR.

Author: pmenon

src/codegen/compact_storage.cpp

@@ -12,7 +12,7 @@
 
 #include "codegen/compact_storage.h"
 
-#include "ips4o/ips4o.hpp"
+#include <algorithm>
 
 #include "codegen/type/sql_type.h"
 
@@ -140,10 +140,10 @@ llvm::Type *CompactStorage::Setup(CodeGen &codegen,
 
   // Sort the entries by decreasing size. This minimizes storage overhead due to
   // padding (potentially) added by LLVM.
-  ips4o::sort(storage_format_.begin(), storage_format_.end(),
-              [](const EntryInfo &left, const EntryInfo &right) {
-                return right.num_bytes < left.num_bytes;
-              });
+  std::sort(storage_format_.begin(), storage_format_.end(),
+            [](const EntryInfo &left, const EntryInfo &right) {
+              return right.num_bytes < left.num_bytes;
+            });
 
   // Now we construct the LLVM type of this storage space. First comes bytes
   // to manage the null bitmap. Then all the data elements.

src/codegen/updateable_storage.cpp

@@ -12,7 +12,7 @@
 
 #include "codegen/updateable_storage.h"
 
-#include "ips4o/ips4o.hpp"
+#include <algorithm>
 
 #include "codegen/lang/if.h"
 #include "codegen/type/sql_type.h"
@@ -66,11 +66,11 @@ llvm::Type *UpdateableStorage::Finalize(CodeGen &codegen) {
   }
 
   // Sort the entries by decreasing size
-  ips4o::sort(storage_format_.begin(), storage_format_.end(),
-              [](const CompactStorage::EntryInfo &left,
-                 const CompactStorage::EntryInfo &right) {
-                return right.num_bytes < left.num_bytes;
-              });
+  std::sort(storage_format_.begin(), storage_format_.end(),
+            [](const CompactStorage::EntryInfo &left,
+               const CompactStorage::EntryInfo &right) {
+              return right.num_bytes < left.num_bytes;
+            });
 
   // Now we construct the LLVM type of this storage space
   std::vector<llvm::Type *> llvm_types;

src/codegen/util/sorter.cpp

@@ -12,10 +12,9 @@
 
 #include "codegen/util/sorter.h"
 
+#include <algorithm>
 #include <queue>
 
-#include "ips4o/ips4o.hpp"
-
 #include "common/synchronization/count_down_latch.h"
 #include "common/timer.h"
 #include "threadpool/mono_queue_pool.h"
@@ -87,8 +86,10 @@ void Sorter::Sort() {
   timer.Start();
 
   // Sort the sucker
+  // TODO(pmenon): The standard std::sort is super slow. We should consider a
+  //               switch to IPS4O which is up to 3-4x faster.
   auto cmp = [this](char *l, char *r) { return cmp_func_(l, r) < 0; };
-  ips4o::sort(tuples_.begin(), tuples_.end(), cmp);
+  std::sort(tuples_.begin(), tuples_.end(), cmp);
 
   // Setup pointers
   tuples_start_ = tuples_.data();
@@ -170,7 +171,7 @@ void Sorter::SortParallel(
     // Sort the local separators and choose the median
     char *separator = nullptr;
     if (idx < separators.size() - 1) {
-      ips4o::sort(separators[idx].begin(), separators[idx].end(), cmp);
+      std::sort(separators[idx].begin(), separators[idx].end(), cmp);
       separator = separators[idx][sorters.size() / 2];
     }