Make bugpoint *much* more powerful, giving it the capability to delete instructions
out of a large function to reduce it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5408 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/bugpoint/CrashDebugger.cpp b/tools/bugpoint/CrashDebugger.cpp
index c69ca45..daf3915 100644
--- a/tools/bugpoint/CrashDebugger.cpp
+++ b/tools/bugpoint/CrashDebugger.cpp
@@ -114,18 +114,63 @@
delete Program;
Program = M;
}
+
+ if (CountFunctions(Program) > 1) {
+ std::cout << "\n*** Couldn't reduce testcase to one function.\n"
+ << " Attempting to remove individual functions.\n";
+ std::cout << "XXX Individual function removal unimplemented!\n";
+ }
}
- if (CountFunctions(Program) > 1) {
- std::cout << "\n*** Couldn't reduce testcase to one function.\n"
- << " Attempting to remove individual functions.\n";
- std::cout << "XXX Individual function removal unimplemented!\n";
- }
+ // FIXME: This should attempt to delete entire basic blocks at a time to speed
+ // up convergence...
- // Now that we have deleted the functions that are unneccesary for the
- // program, try to remove instructions and basic blocks that are not neccesary
- // to cause the crash.
- //
+ unsigned Simplification = 4;
+ do {
+ --Simplification;
+ std::cout << "\n*** Attempting to reduce testcase by deleting instruc"
+ << "tions: Simplification Level #" << Simplification << "\n";
+
+ // Now that we have deleted the functions that are unneccesary for the
+ // program, try to remove instructions that are not neccesary to cause the
+ // crash. To do this, we loop through all of the instructions in the
+ // remaining functions, deleting them (replacing any values produced with
+ // nulls), and then running ADCE and SimplifyCFG. If the transformed input
+ // still triggers failure, keep deleting until we cannot trigger failure
+ // anymore.
+ //
+ TryAgain:
+
+ // Loop over all of the (non-terminator) instructions remaining in the
+ // function, attempting to delete them.
+ for (Module::iterator FI = Program->begin(), E = Program->end();
+ FI != E; ++FI)
+ if (!FI->isExternal()) {
+ for (Function::iterator BI = FI->begin(), E = FI->end(); BI != E; ++BI)
+ for (BasicBlock::iterator I = BI->begin(), E = --BI->end();
+ I != E; ++I) {
+ Module *M = deleteInstructionFromProgram(I, Simplification);
+
+ // Make the function the current program...
+ std::swap(Program, M);
+
+ // Find out if the pass still crashes on this pass...
+ std::cout << "Checking instruction '" << I->getName() << "': ";
+ if (runPass(Pass)) {
+ // Yup, it does, we delete the old module, and continue trying to
+ // reduce the testcase...
+ EmitProgressBytecode(Pass, "reduced-" + I->getName());
+ delete M;
+ goto TryAgain; // I wish I had a multi-level break here!
+ }
+
+ // This pass didn't crash without this instruction, try the next
+ // one.
+ delete Program;
+ Program = M;
+ }
+ }
+ } while (Simplification);
return false;
}