There's no need to consider PHI nodes in the same block as the instruction

we're inserting sigma/phi functions for. Patch by Andre Tavares.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75138 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/Transforms/Utils/SSI.cpp b/lib/Transforms/Utils/SSI.cpp
index caafb31..0585561 100644
--- a/lib/Transforms/Utils/SSI.cpp
+++ b/lib/Transforms/Utils/SSI.cpp
@@ -282,12 +282,16 @@ void SSI::substituteUse(Instruction *I) {
 }
 
 /// Test if the BasicBlock BB dominates any use or definition of value.
+/// If it dominates a phi instruction that is on the same BasicBlock,
+/// that does not count.
 ///
 bool SSI::dominateAny(BasicBlock *BB, Instruction *value) {
   for (Value::use_iterator begin = value->use_begin(),
        end = value->use_end(); begin != end; ++begin) {
     Instruction *I = cast<Instruction>(*begin);
     BasicBlock *BB_father = I->getParent();
+    if (BB == BB_father && isa<PHINode>(I))
+      continue;
     if (DT_->dominates(BB, BB_father)) {
       return true;
     }