[NewGVN] Replace predicate info leftovers.

This time with an additional fix, i.e. we remove the dead
@llvm.ssa.copy instruction.

llvm-svn: 303385

diff --git a/llvm/lib/Transforms/Scalar/NewGVN.cpp b/llvm/lib/Transforms/Scalar/NewGVN.cpp
index 0e7572f..34b93a8 100644 (file)
--- a/llvm/lib/Transforms/Scalar/NewGVN.cpp
+++ b/llvm/lib/Transforms/Scalar/NewGVN.cpp
@@ -3301,6 +3301,10 @@ bool NewGVN::eliminateInstructions(Function &F) {
 
           Value *DominatingLeader = EliminationStack.back();
 
+          auto *II = dyn_cast<IntrinsicInst>(DominatingLeader);
+          if (II && II->getIntrinsicID() == Intrinsic::ssa_copy)
+            DominatingLeader = II->getOperand(0);
+
           // Don't replace our existing users with ourselves.
           if (U->get() == DominatingLeader)
             continue;
@@ -3321,6 +3325,8 @@ bool NewGVN::eliminateInstructions(Function &F) {
           // It's about to be alive again.
           if (LeaderUseCount == 0 && isa<Instruction>(DominatingLeader))
             ProbablyDead.erase(cast<Instruction>(DominatingLeader));
+          if (LeaderUseCount == 0 && II)
+            ProbablyDead.insert(II);
           ++LeaderUseCount;
           AnythingReplaced = true;
         }

diff --git a/llvm/test/Transforms/NewGVN/pr32945.ll b/llvm/test/Transforms/NewGVN/pr32945.ll
new file mode 100644 (file)
index 0000000..553ba4b
--- /dev/null
+++ b/llvm/test/Transforms/NewGVN/pr32945.ll
@@ -0,0 +1,24 @@
+; RUN: opt -S -newgvn %s | FileCheck %s
+; CHECK-NOT: call i32 @llvm.ssa.copy
+
+@d = external global i32
+@e = external global i32
+define void @tinkywinky() {
+  br i1 true, label %lor.lhs.false, label %cond.true
+lor.lhs.false:
+  %tmp = load i32, i32* @d, align 4
+  %patatino = load i32, i32* null, align 4
+  %or = or i32 %tmp, %patatino
+  store i32 %or, i32* @d, align 4
+  br label %cond.true
+cond.true:
+  %tmp1 = load i32, i32* @e, align 4
+  %tmp2 = load i32, i32* @d, align 4
+  %cmp = icmp eq i32 %tmp1, %tmp2
+  br i1 %cmp, label %cond.true6, label %cond.false
+cond.true6:
+  %cmp7 = icmp slt i32 %tmp1, 0
+  br i1 %cmp7, label %cond.false, label %cond.false
+cond.false:
+  ret void
+}