[llvm-commits] CVS: llvm/tools/bugpoint/Miscompilation.cpp

[Chris Lattner]

Changes in directory llvm/tools/bugpoint:

Miscompilation.cpp updated: 1.38 -> 1.39

---
Log message:

Disambiguate symbols after loop extraction so that we can diagnose a code
generator bug if multiple loops are extracted from a function.


---
Diffs of the changes:  (+18 -16)

Index: llvm/tools/bugpoint/Miscompilation.cpp
diff -u llvm/tools/bugpoint/Miscompilation.cpp:1.38 llvm/tools/bugpoint/Miscompilation.cpp:1.39
--- llvm/tools/bugpoint/Miscompilation.cpp:1.38	Fri Apr  9 17:28:33 2004
+++ llvm/tools/bugpoint/Miscompilation.cpp	Sun Apr 11 18:52:35 2004
@@ -201,6 +201,19 @@
   return TestFn(BD, ToOptimize, ToNotOptimize);
 }
 
+static void DisambiguateGlobalSymbols(Module *M) {
+  // Try not to cause collisions by minimizing chances of renaming an
+  // already-external symbol, so take in external globals and functions as-is.
+  // The code should work correctly without disambiguation (assuming the same
+  // mangler is used by the two code generators), but having symbols with the
+  // same name causes warnings to be emitted by the code generator.
+  Mangler Mang(*M);
+  for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+    I->setName(Mang.getValueName(I));
+  for (Module::iterator  I = M->begin(),  E = M->end();  I != E; ++I)
+    I->setName(Mang.getValueName(I));
+}
+
 /// ExtractLoops - Given a reduced list of functions that still exposed the bug,
 /// check to see if we can extract the loops in the region without obscuring the
 /// bug.  If so, it reduces the amount of code identified.
@@ -321,6 +334,11 @@
     // Okay, we extracted some loops and the problem still appears.  See if we
     // can eliminate some of the created functions from being candidates.
 
+    // Loop extraction can introduce functions with the same name (foo_code).
+    // Make sure to disambiguate the symbols so that when the program is split
+    // apart that we can link it back together again.
+    DisambiguateGlobalSymbols(BD.getProgram());
+
     // Do the reduction...
     ReduceMiscompilingFunctions(BD, TestFn).reduceList(MiscompiledFunctions);
     
@@ -547,22 +565,6 @@
 
   return Result;
 }
-
-
-
-static void DisambiguateGlobalSymbols(Module *M) {
-  // Try not to cause collisions by minimizing chances of renaming an
-  // already-external symbol, so take in external globals and functions as-is.
-  // The code should work correctly without disambiguation (assuming the same
-  // mangler is used by the two code generators), but having symbols with the
-  // same name causes warnings to be emitted by the code generator.
-  Mangler Mang(*M);
-  for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
-    I->setName(Mang.getValueName(I));
-  for (Module::iterator  I = M->begin(),  E = M->end();  I != E; ++I)
-    I->setName(Mang.getValueName(I));
-}
-
 
 
 bool BugDriver::debugCodeGenerator() {