[llvm] r322299 - [Hexagon] Impose limits on container sizes in HexagonGenInsert

[Krzysztof Parzyszek via llvm-commits]

Author: kparzysz
Date: Thu Jan 11 10:02:13 2018
New Revision: 322299

URL: http://llvm.org/viewvc/llvm-project?rev=322299&view=rev
Log:
[Hexagon] Impose limits on container sizes in HexagonGenInsert

With over 300k virtual registers, the size of the data exceeded 12GB.
Impose limits on how much information is collected.


Modified:
    llvm/trunk/lib/Target/Hexagon/HexagonGenInsert.cpp

Modified: llvm/trunk/lib/Target/Hexagon/HexagonGenInsert.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonGenInsert.cpp?rev=322299&r1=322298&r2=322299&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonGenInsert.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonGenInsert.cpp Thu Jan 11 10:02:13 2018
@@ -55,6 +55,12 @@ static cl::opt<unsigned> VRegDistCutoff(
   cl::Hidden, cl::ZeroOrMore, cl::desc("Vreg distance cutoff for insert "
   "generation."));
 
+// Limit the container sizes for extreme cases where we run out of memory.
+static cl::opt<unsigned> MaxORLSize("insert-max-orl", cl::init(4096),
+  cl::Hidden, cl::ZeroOrMore, cl::desc("Maximum size of OrderedRegisterList"));
+static cl::opt<unsigned> MaxIFMSize("insert-max-ifmap", cl::init(1024),
+  cl::Hidden, cl::ZeroOrMore, cl::desc("Maximum size of IFMap"));
+
 static cl::opt<bool> OptTiming("insert-timing", cl::init(false), cl::Hidden,
   cl::ZeroOrMore, cl::desc("Enable timing of insert generation"));
 static cl::opt<bool> OptTimingDetail("insert-timing-detail", cl::init(false),
@@ -86,6 +92,7 @@ namespace {
   struct RegisterSet : private BitVector {
     RegisterSet() = default;
     explicit RegisterSet(unsigned s, bool t = false) : BitVector(s, t) {}
+    RegisterSet(const RegisterSet &RS) : BitVector(RS) {}
 
     using BitVector::clear;
 
@@ -370,9 +377,11 @@ namespace {
 
   class OrderedRegisterList {
     using ListType = std::vector<unsigned>;
+    const unsigned MaxSize;
 
   public:
-    OrderedRegisterList(const RegisterOrdering &RO) : Ord(RO) {}
+    OrderedRegisterList(const RegisterOrdering &RO)
+      : MaxSize(MaxORLSize), Ord(RO) {}
 
     void insert(unsigned VR);
     void remove(unsigned VR);
@@ -433,12 +442,17 @@ void OrderedRegisterList::insert(unsigne
     Seq.push_back(VR);
   else
     Seq.insert(L, VR);
+
+  unsigned S = Seq.size();
+  if (S > MaxSize)
+    Seq.resize(MaxSize);
+  assert(Seq.size() <= MaxSize);
 }
 
 void OrderedRegisterList::remove(unsigned VR) {
   iterator L = std::lower_bound(Seq.begin(), Seq.end(), VR, Ord);
-  assert(L != Seq.end());
-  Seq.erase(L);
+  if (L != Seq.end())
+    Seq.erase(L);
 }
 
 namespace {
@@ -950,6 +964,9 @@ void HexagonGenInsert::collectInBlock(Ma
           continue;
 
         findRecordInsertForms(VR, AVs);
+        // Stop if the map size is too large.
+        if (IFMap.size() > MaxIFMSize)
+          return;
       }
     }