contrib/llvm/patches/patch-12-add-llvm-gvn-option.diff

   1 Add an llvm option to enable/disable running the global value numbering
   2 optimization pass.  Disabling this pass helps to minimize the size of
   3 boot2.
   4
   5 Introduced here: http://svnweb.freebsd.org/changeset/base/274968
   6
   7 Index: lib/Transforms/IPO/PassManagerBuilder.cpp
   8 ===================================================================
   9 --- lib/Transforms/IPO/PassManagerBuilder.cpp
  10 +++ lib/Transforms/IPO/PassManagerBuilder.cpp
  11 @@ -57,6 +57,10 @@ static cl::opt<bool> RunLoadCombine("combine-loads
  12                                      cl::Hidden,
  13                                      cl::desc("Run the load combining pass"));
  14
  15 +static cl::opt<bool> RunGVN("enable-gvn", cl::init(true),
  16 +                            cl::Hidden,
  17 +                            cl::desc("Run the global value numbering pass"));
  18 +
  19  PassManagerBuilder::PassManagerBuilder() {
  20      OptLevel = 2;
  21      SizeLevel = 0;
  22 @@ -210,7 +214,8 @@ void PassManagerBuilder::populateModulePassManager
  23
  24    if (OptLevel > 1) {
  25      MPM.add(createMergedLoadStoreMotionPass()); // Merge load/stores in diamond
  26 -    MPM.add(createGVNPass());                 // Remove redundancies
  27 +    if (RunGVN)
  28 +      MPM.add(createGVNPass());                 // Remove redundancies
  29    }
  30    MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
  31    MPM.add(createSCCPPass());                  // Constant prop with SCCP