[llvm-commits] CVS: llvm/lib/Analysis/DataStructure/DataStructure.cpp

[Chris Lattner]

Changes in directory llvm/lib/Analysis/DataStructure:

DataStructure.cpp updated: 1.207 -> 1.208
---
Log message:

Do not create ridiculously huge DSNodes, as described in the comments.
This speeds up the BU pass on 172.mgrid from 62.3 -> 0.1242s.


---
Diffs of the changes:  (+21 -1)

 DataStructure.cpp |   22 +++++++++++++++++++++-
 1 files changed, 21 insertions(+), 1 deletion(-)


Index: llvm/lib/Analysis/DataStructure/DataStructure.cpp
diff -u llvm/lib/Analysis/DataStructure/DataStructure.cpp:1.207 llvm/lib/Analysis/DataStructure/DataStructure.cpp:1.208
--- llvm/lib/Analysis/DataStructure/DataStructure.cpp:1.207	Wed Mar 16 16:42:19 2005
+++ llvm/lib/Analysis/DataStructure/DataStructure.cpp	Wed Mar 16 23:25:34 2005
@@ -382,13 +382,23 @@
     // question....
     assert(Offset == 0 && !isArray() &&
            "Cannot have an offset into a void node!");
+
+    // If this node would have to have an unreasonable number of fields, just
+    // collapse it.  This can occur for fortran common blocks, which have stupid
+    // things like { [100000000 x double], [1000000 x double] }.
+    unsigned NumFields = (NewTySize+DS::PointerSize-1) >> DS::PointerShift;
+    if (NumFields > 64) {
+      foldNodeCompletely();
+      return true;
+    }
+
     Ty = NewTy;
     NodeType &= ~Array;
     if (WillBeArray) NodeType |= Array;
     Size = NewTySize;
 
     // Calculate the number of outgoing links from this node.
-    Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
+    Links.resize(NumFields);
     return false;
   }
 
@@ -418,6 +428,16 @@
     Ty = NewTy;
     NodeType &= ~Array;
     if (WillBeArray) NodeType |= Array;
+
+    // If this node would have to have an unreasonable number of fields, just
+    // collapse it.  This can occur for fortran common blocks, which have stupid
+    // things like { [100000000 x double], [1000000 x double] }.
+    unsigned NumFields = (NewTySize+DS::PointerSize-1) >> DS::PointerShift;
+    if (NumFields > 64) {
+      foldNodeCompletely();
+      return true;
+    }
+
     Size = NewTySize;
 
     // Must grow links to be the appropriate size...