Revert "[memcpyopt] Teach memcpyopt to optimize across basic blocks"

This reverts r321138. It seems there are still underlying issues with
memdep. PR35519 seems to still be present if debug info is enabled. We
end up losing a memcpy. Somehow during store to memset merging, we
insert the memset after the memcpy or fail to update the memdep analysis
to account for the newly inserted memset of a pair.

Reduced test case:

  #include <assert.h>
  #include <stdio.h>
  #include <string>
  #include <utility>
  #include <vector>

  void do_push_back(
      std::vector<std::pair<std::string, std::vector<std::string>>>* crls) {
    crls->push_back(std::make_pair(std::string(), std::vector<std::string>()));
  }

  int __attribute__((optnone)) main() {
    // Put some data in the vector and then remove it so we take the push_back
    // fast path.
    std::vector<std::pair<std::string, std::vector<std::string>>> crl_set;
    crl_set.push_back({"asdf", {}});
    crl_set.pop_back();
    printf("first word in vector storage: %p\n", *(void**)crl_set.data());

    // Do the push_back which may fail to initialize the data.
    do_push_back(&crl_set);
    auto* first = &crl_set.back().first;
    printf("first word in vector storage (should be zero): %p\n",
           *(void**)crl_set.data());
    assert(first->empty());
    puts("ok");
  }

Compile with libc++, enable optimizations, and enable debug info:
$ clang++ -stdlib=libc++ -g -O2 t.cpp -o t.exe -Wl,-rpath=llvm/build/lib

This program will assert with this change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321510 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 6 deletions

diff --git a/include/llvm/Analysis/MemoryDependenceAnalysis.h b/include/llvm/Analysis/MemoryDependenceAnalysis.h
index 391a333594e9..c2974525a6ff 100644
--- a/include/llvm/Analysis/MemoryDependenceAnalysis.h
+++ b/include/llvm/Analysis/MemoryDependenceAnalysis.h
@@ -407,12 +407,6 @@ public:
   void getNonLocalPointerDependency(Instruction *QueryInst,
                                     SmallVectorImpl<NonLocalDepResult> &Result);
 
-  /// Perform a dependency query specifically for QueryInst's access to Loc.
-  /// The other comments for getNonLocalPointerDependency apply here as well.
-  void getNonLocalPointerDependencyFrom(Instruction *QueryInst,
-                                        const MemoryLocation &Loc, bool isLoad,
-                                        SmallVectorImpl<NonLocalDepResult> &Result);
-
   /// Removes an instruction from the dependence analysis, updating the
   /// dependence of instructions that previously depended on it.
   void removeInstruction(Instruction *InstToRemove);