Don't bother value numbering instructions with void types in GVN. In theory this...

fewer things into the value numbering maps, but any speedup is beneath the noise threshold on my machine
on 403.gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122844 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 010d6c9fdf214cb4285e512531899bf945d559f1..b7fc9c30e06d6a3b3e1f542a0023046bff432535 100644 (file)
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1685,6 +1685,10 @@ bool GVN::processInstruction(Instruction *I,
     return false;
   }
   
+  // Instructions with void type don't return a value, so there's
+  // no point in trying to find redudancies in them.
+  if (I->getType()->isVoidTy()) return false;
+  
   uint32_t NextNum = VN.getNextUnusedValueNumber();
   unsigned Num = VN.lookup_or_add(I);