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Diffstat (limited to 'contrib/llvm/tools/bugpoint/ListReducer.h')
-rw-r--r-- | contrib/llvm/tools/bugpoint/ListReducer.h | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/contrib/llvm/tools/bugpoint/ListReducer.h b/contrib/llvm/tools/bugpoint/ListReducer.h deleted file mode 100644 index bd1c5da..0000000 --- a/contrib/llvm/tools/bugpoint/ListReducer.h +++ /dev/null @@ -1,201 +0,0 @@ -//===- ListReducer.h - Trim down list while retaining property --*- C++ -*-===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This class is to be used as a base class for operations that want to zero in -// on a subset of the input which still causes the bug we are tracking. -// -//===----------------------------------------------------------------------===// - -#ifndef BUGPOINT_LIST_REDUCER_H -#define BUGPOINT_LIST_REDUCER_H - -#include "llvm/Support/raw_ostream.h" -#include "llvm/Support/ErrorHandling.h" -#include <vector> -#include <cstdlib> -#include <algorithm> - -namespace llvm { - - extern bool BugpointIsInterrupted; - -template<typename ElTy> -struct ListReducer { - enum TestResult { - NoFailure, // No failure of the predicate was detected - KeepSuffix, // The suffix alone satisfies the predicate - KeepPrefix, // The prefix alone satisfies the predicate - InternalError // Encountered an error trying to run the predicate - }; - - virtual ~ListReducer() {} - - // doTest - This virtual function should be overriden by subclasses to - // implement the test desired. The testcase is only required to test to see - // if the Kept list still satisfies the property, but if it is going to check - // the prefix anyway, it can. - // - virtual TestResult doTest(std::vector<ElTy> &Prefix, - std::vector<ElTy> &Kept, - std::string &Error) = 0; - - // reduceList - This function attempts to reduce the length of the specified - // list while still maintaining the "test" property. This is the core of the - // "work" that bugpoint does. - // - bool reduceList(std::vector<ElTy> &TheList, std::string &Error) { - std::vector<ElTy> empty; - std::srand(0x6e5ea738); // Seed the random number generator - switch (doTest(TheList, empty, Error)) { - case KeepPrefix: - if (TheList.size() == 1) // we are done, it's the base case and it fails - return true; - else - break; // there's definitely an error, but we need to narrow it down - - case KeepSuffix: - // cannot be reached! - llvm_unreachable("bugpoint ListReducer internal error: " - "selected empty set."); - - case NoFailure: - return false; // there is no failure with the full set of passes/funcs! - - case InternalError: - assert(!Error.empty()); - return true; - } - - // Maximal number of allowed splitting iterations, - // before the elements are randomly shuffled. - const unsigned MaxIterationsWithoutProgress = 3; - bool ShufflingEnabled = true; - -Backjump: - unsigned MidTop = TheList.size(); - unsigned MaxIterations = MaxIterationsWithoutProgress; - unsigned NumOfIterationsWithoutProgress = 0; - while (MidTop > 1) { // Binary split reduction loop - // Halt if the user presses ctrl-c. - if (BugpointIsInterrupted) { - errs() << "\n\n*** Reduction Interrupted, cleaning up...\n\n"; - return true; - } - - // If the loop doesn't make satisfying progress, try shuffling. - // The purpose of shuffling is to avoid the heavy tails of the - // distribution (improving the speed of convergence). - if (ShufflingEnabled && - NumOfIterationsWithoutProgress > MaxIterations) { - std::vector<ElTy> ShuffledList(TheList); - std::random_shuffle(ShuffledList.begin(), ShuffledList.end()); - errs() << "\n\n*** Testing shuffled set...\n\n"; - // Check that random shuffle doesn't loose the bug - if (doTest(ShuffledList, empty, Error) == KeepPrefix) { - // If the bug is still here, use the shuffled list. - TheList.swap(ShuffledList); - MidTop = TheList.size(); - // Must increase the shuffling treshold to avoid the small - // probability of inifinite looping without making progress. - MaxIterations += 2; - errs() << "\n\n*** Shuffling does not hide the bug...\n\n"; - } else { - ShufflingEnabled = false; // Disable shuffling further on - errs() << "\n\n*** Shuffling hides the bug...\n\n"; - } - NumOfIterationsWithoutProgress = 0; - } - - unsigned Mid = MidTop / 2; - std::vector<ElTy> Prefix(TheList.begin(), TheList.begin()+Mid); - std::vector<ElTy> Suffix(TheList.begin()+Mid, TheList.end()); - - switch (doTest(Prefix, Suffix, Error)) { - case KeepSuffix: - // The property still holds. We can just drop the prefix elements, and - // shorten the list to the "kept" elements. - TheList.swap(Suffix); - MidTop = TheList.size(); - // Reset progress treshold and progress counter - MaxIterations = MaxIterationsWithoutProgress; - NumOfIterationsWithoutProgress = 0; - break; - case KeepPrefix: - // The predicate still holds, shorten the list to the prefix elements. - TheList.swap(Prefix); - MidTop = TheList.size(); - // Reset progress treshold and progress counter - MaxIterations = MaxIterationsWithoutProgress; - NumOfIterationsWithoutProgress = 0; - break; - case NoFailure: - // Otherwise the property doesn't hold. Some of the elements we removed - // must be necessary to maintain the property. - MidTop = Mid; - NumOfIterationsWithoutProgress++; - break; - case InternalError: - return true; // Error was set by doTest. - } - assert(Error.empty() && "doTest did not return InternalError for error"); - } - - // Probability of backjumping from the trimming loop back to the binary - // split reduction loop. - const int BackjumpProbability = 10; - - // Okay, we trimmed as much off the top and the bottom of the list as we - // could. If there is more than two elements in the list, try deleting - // interior elements and testing that. - // - if (TheList.size() > 2) { - bool Changed = true; - std::vector<ElTy> EmptyList; - while (Changed) { // Trimming loop. - Changed = false; - - // If the binary split reduction loop made an unfortunate sequence of - // splits, the trimming loop might be left off with a huge number of - // remaining elements (large search space). Backjumping out of that - // search space and attempting a different split can significantly - // improve the convergence speed. - if (std::rand() % 100 < BackjumpProbability) - goto Backjump; - - for (unsigned i = 1; i < TheList.size()-1; ++i) { // Check interior elts - if (BugpointIsInterrupted) { - errs() << "\n\n*** Reduction Interrupted, cleaning up...\n\n"; - return true; - } - - std::vector<ElTy> TestList(TheList); - TestList.erase(TestList.begin()+i); - - if (doTest(EmptyList, TestList, Error) == KeepSuffix) { - // We can trim down the list! - TheList.swap(TestList); - --i; // Don't skip an element of the list - Changed = true; - } - if (!Error.empty()) - return true; - } - // This can take a long time if left uncontrolled. For now, don't - // iterate. - break; - } - } - - return true; // there are some failure and we've narrowed them down - } -}; - -} // End llvm namespace - -#endif |