[llvm-commits] CVS: llvm/lib/Transforms/Instrumentation/TraceValues.cpp

[Vikram Adve]

Changes in directory llvm/lib/Transforms/Instrumentation:

TraceValues.cpp updated: 1.57 -> 1.58

---
Log message:

Trace loads and stores as they happen (stores were being 
remembered in valuesStoredInFunction, but never traced at function return,
and that's too late to be finding the error anyway).
Stores trace both the value and the address being stored to,
but after some experience I think only values should be traced.
The pointer hash table just fills up far too quickly if every
store address were traced.


---
Diffs of the changes:

Index: llvm/lib/Transforms/Instrumentation/TraceValues.cpp
diff -u llvm/lib/Transforms/Instrumentation/TraceValues.cpp:1.57 llvm/lib/Transforms/Instrumentation/TraceValues.cpp:1.58
--- llvm/lib/Transforms/Instrumentation/TraceValues.cpp:1.57	Wed Jun  4 23:48:18 2003
+++ llvm/lib/Transforms/Instrumentation/TraceValues.cpp	Fri Jul 11 16:57:43 2003
@@ -164,7 +164,9 @@
 
 // 
 // Check if this instruction has any uses outside its basic block,
-// or if it used by either a Call or Return instruction.
+// or if it used by either a Call or Return instruction (ditto).
+// (Values stored to memory within this BB are live at end of BB but are
+// traced at the store instruction, not where they are computed.)
 // 
 static inline bool LiveAtBBExit(const Instruction* I) {
   const BasicBlock *BB = I->getParent();
@@ -188,10 +190,16 @@
 }
 
 
+// Trace a value computed by an instruction if it is non-void, it is computed
+// by a real computation, not just a copy (see TraceThisOpCode), and
+// -- it is a load instruction: we want to check values read from memory
+// -- or it is live at exit from the basic block (i.e., ignore local temps)
+// 
 static bool ShouldTraceValue(const Instruction *I) {
   return
-    I->getType() != Type::VoidTy && LiveAtBBExit(I) &&
-    TraceThisOpCode(I->getOpcode());
+    I->getType() != Type::VoidTy &&
+    TraceThisOpCode(I->getOpcode()) &&
+    (isa<LoadInst>(I) || LiveAtBBExit(I));
 }
 
 static string getPrintfCodeFor(const Value *V) {
@@ -331,14 +339,13 @@
   // 
   for (BasicBlock::iterator II = BB->begin(); &*II != InsertPos; ++II) {
     if (StoreInst *SI = dyn_cast<StoreInst>(II)) {
-      assert(valuesStoredInFunction &&
-             "Should not be printing a store instruction at function exit");
-      LoadInst *LI = new LoadInst(SI->getPointerOperand(), "reload." +
-                                  SI->getPointerOperand()->getName(),
-                                  InsertPos);
-      valuesStoredInFunction->push_back(LI);
+      // Trace the stored value and address
+      InsertVerbosePrintInst(SI->getOperand(0), BB, InsertPos,
+                             "  (store value) ", Printf, HashPtrToSeqNum);
+      InsertVerbosePrintInst(SI->getOperand(1), BB, InsertPos,
+                             "  (store addr ) ", Printf, HashPtrToSeqNum);
     }
-    if (ShouldTraceValue(II))
+    else if (ShouldTraceValue(II))
       InsertVerbosePrintInst(II, BB, InsertPos, "  ", Printf, HashPtrToSeqNum);
   }
 }