GH #49: Run GVN again after InstCombine.

rust-lang · Jul 30, 2017 · 2ae0b92 · 2ae0b92
1 parent 48d9493
commit 2ae0b92
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -379,6 +379,8 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   // Run instcombine after redundancy elimination to exploit opportunities
   // opened up by them.
   addInstructionCombiningPass(MPM);
+  if (OptLevel > 1)
+    MPM.add(createGVNPass(DisableGVNLoadPRE));  // Remove redundancies
   addExtensionsToPM(EP_Peephole, MPM);
   MPM.add(createJumpThreadingPass());         // Thread jumps
   MPM.add(createCorrelatedValuePropagationPass());