[llvm-commits] CVS: llvm/lib/VMCore/Verifier.cpp

[Chris Lattner]

Changes in directory llvm/lib/VMCore:

Verifier.cpp updated: 1.118 -> 1.119
---
Log message:

Don't use DominatorSet::dominates for intra-block instruction dom checks.
This method is linear time in the size of the basic block, which is very
bad for large basic blocks.  On the Assembler/2004-09-29-VerifierIsReallySlow.llx
testcase, the verifier changes from taking 50s to 0.23s with this patch.


---
Diffs of the changes:  (+11 -1)

Index: llvm/lib/VMCore/Verifier.cpp
diff -u llvm/lib/VMCore/Verifier.cpp:1.118 llvm/lib/VMCore/Verifier.cpp:1.119
--- llvm/lib/VMCore/Verifier.cpp:1.118	Wed Sep  1 17:55:37 2004
+++ llvm/lib/VMCore/Verifier.cpp	Wed Sep 29 15:07:45 2004
@@ -70,6 +70,12 @@
     DominatorSet *DS;     // Dominator set, caution can be null!
     std::stringstream msgs;  // A stringstream to collect messages
 
+    /// InstInThisBlock - when verifying a basic block, keep track of all of the
+    /// instructions we have seen so far.  This allows us to do efficient
+    /// dominance checks for the case when an instruction has an operand that is
+    /// an instruction in the same block.
+    std::set<Instruction*> InstsInThisBlock;
+
     Verifier() 
         : Broken(false), RealPass(true), action(AbortProcessAction),
           DS(0), msgs( std::ios_base::app | std::ios_base::out ) {}
@@ -101,6 +107,7 @@
       // Get dominator information if we are being run by PassManager
       if (RealPass) DS = &getAnalysis<DominatorSet>();
       visit(F);
+      InstsInThisBlock.clear();
 
       // If this is a real pass, in a pass manager, we must abort before
       // returning back to the pass manager, or else the pass manager may try to
@@ -312,6 +319,8 @@
 // verifyBasicBlock - Verify that a basic block is well formed...
 //
 void Verifier::visitBasicBlock(BasicBlock &BB) {
+  InstsInThisBlock.clear();
+
   // Check constraints that this basic block imposes on all of the PHI nodes in
   // it.
   if (isa<PHINode>(BB.front())) {
@@ -592,7 +601,7 @@
         else if (OpBlock == BB) {
           // If they are in the same basic block, make sure that the definition
           // comes before the use.
-          Assert2(DS->dominates(Op, &I) ||
+          Assert2(InstsInThisBlock.count(Op) ||
                   !DS->dominates(&BB->getParent()->getEntryBlock(), BB),
                   "Instruction does not dominate all uses!", Op, &I);
         }
@@ -611,6 +620,7 @@
       }
     }
   }
+  InstsInThisBlock.insert(&I);
 }
 
 /// visitIntrinsicFunction - Allow intrinsics to be verified in different ways.