There are times when the coalescer would not coalesce away a copy but the copy

[oota-llvm.git] / lib / CodeGen / MachineModuleInfo.cpp

diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 32d8394527a1ae7d3447e03181108ee0c1248d7f..8360745ff167268a5c6619287b56f3ee2875e067 100644 (file)
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -1476,6 +1476,8 @@ MachineModuleInfo::MachineModuleInfo()
 , FrameMoves()
 , LandingPads()
 , Personalities()
+, CallsEHReturn(0)
+, CallsUnwindInit(0)
 {
   // Always emit "no personality" info
   Personalities.push_back(NULL);
@@ -1522,6 +1524,9 @@ void MachineModuleInfo::EndFunction() {
   LandingPads.clear();
   TypeInfos.clear();
   FilterIds.clear();
+  FilterEnds.clear();
+  CallsEHReturn = 0;
+  CallsUnwindInit = 0;
 }
 
 /// getDescFor - Convert a Value to a debug information descriptor.
@@ -1721,6 +1726,13 @@ void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad,
   LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
 }
 
+/// addCleanup - Add a cleanup action for a landing pad.
+///
+void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
+  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
+  LP.TypeIds.push_back(0);
+}
+
 /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
 /// pads.
 void MachineModuleInfo::TidyLandingPads() {
@@ -1734,12 +1746,12 @@ void MachineModuleInfo::TidyLandingPads() {
       LandingPads.erase(LandingPads.begin() + i);
       continue;
     }
-          
+
     for (unsigned j=0; j != LandingPads[i].BeginLabels.size(); ) {
       unsigned BeginLabel = MappedLabel(LandingPad.BeginLabels[j]);
       unsigned EndLabel = MappedLabel(LandingPad.EndLabels[j]);
-            
-          
+
+
       if (!BeginLabel || !EndLabel) {
         LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
         LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
@@ -1750,7 +1762,19 @@ void MachineModuleInfo::TidyLandingPads() {
       LandingPad.EndLabels[j] = EndLabel;
       ++j;
     }
-    
+
+    // Remove landing pads with no try-ranges.
+    if (!LandingPads[i].BeginLabels.size()) {
+      LandingPads.erase(LandingPads.begin() + i);
+      continue;
+    }
+
+    // If there is no landing pad, ensure that the list of typeids is empty.
+    // If the only typeid is a cleanup, this is the same as having no typeids.
+    if (!LandingPad.LandingPadBlock ||
+        (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
+      LandingPad.TypeIds.clear();
+
     ++i;
   }
 }
@@ -1768,13 +1792,30 @@ unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) {
 /// getFilterIDFor - Return the filter id for the specified typeinfos.  This is
 /// function wide.
 int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
-  // TODO: map duplicate filters to the same filter id; a filter equal to the
-  // tail of an existing filter also need not be added; re-order filters and
-  // filter elements to maximize this kind of sharing.
+  // If the new filter coincides with the tail of an existing filter, then
+  // re-use the existing filter.  Folding filters more than this requires
+  // re-ordering filters and/or their elements - probably not worth it.
+  for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
+       E = FilterEnds.end(); I != E; ++I) {
+    unsigned i = *I, j = TyIds.size();
+
+    while (i && j)
+      if (FilterIds[--i] != TyIds[--j])
+        goto try_next;
+
+    if (!j)
+      // The new filter coincides with range [i, end) of the existing filter.
+      return -(1 + i);
+
+try_next:;
+  }
+
+  // Add the new filter.
   int FilterID = -(1 + FilterIds.size());
   FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
   for (unsigned I = 0, N = TyIds.size(); I != N; ++I)
     FilterIds.push_back(TyIds[I]);
+  FilterEnds.push_back(FilterIds.size());
   FilterIds.push_back(0); // terminator
   return FilterID;
 }