[IR] Replace `isa<TerminatorInst>` with `isTerminator()`.

This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.

All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.

3 files changed, 5 insertions, 4 deletions

diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
index 48d8b20cd85..c1918f5b866 100644
--- a/polly/lib/Analysis/ScopBuilder.cpp
+++ b/polly/lib/Analysis/ScopBuilder.cpp
@@ -685,7 +685,7 @@ void ScopBuilder::buildAccessFunctions() {
 }
 
 bool ScopBuilder::shouldModelInst(Instruction *Inst, Loop *L) {
-  return !isa<TerminatorInst>(Inst) && !isIgnoredIntrinsic(Inst) &&
+  return !Inst->isTerminator() && !isIgnoredIntrinsic(Inst) &&
          !canSynthesize(Inst, *scop, &SE, L);
 }
 
@@ -1399,7 +1399,7 @@ static void verifyUses(Scop *S, LoopInfo &LI, DominatorTree &DT) {
         continue;
 
       // Branch conditions are encoded in the statement domains.
-      if (isa<TerminatorInst>(&Inst) && Stmt->isBlockStmt())
+      if (Inst.isTerminator() && Stmt->isBlockStmt())
         continue;
 
       // Verify all uses.
diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
index 41b9aaf3099..666ac34ea57 100644
--- a/polly/lib/Analysis/ScopDetection.cpp
+++ b/polly/lib/Analysis/ScopDetection.cpp
@@ -1214,7 +1214,8 @@ bool ScopDetection::isValidInstruction(Instruction &Inst,
       auto *PHI = dyn_cast<PHINode>(OpInst);
       if (PHI) {
         for (User *U : PHI->users()) {
-          if (!isa<TerminatorInst>(U))
+          auto *UI = dyn_cast<Instruction>(U);
+          if (!UI || !UI->isTerminator())
             return false;
         }
       } else {
diff --git a/polly/lib/Support/VirtualInstruction.cpp b/polly/lib/Support/VirtualInstruction.cpp
index a1fa03e7019..f779368ab72 100644
--- a/polly/lib/Support/VirtualInstruction.cpp
+++ b/polly/lib/Support/VirtualInstruction.cpp
@@ -178,7 +178,7 @@ static bool isRoot(const Instruction *Inst) {
 
   // Terminator instructions (in region statements) are required for control
   // flow.
-  if (isa<TerminatorInst>(Inst))
+  if (Inst->isTerminator())
     return true;
 
   // Writes to memory must be honored.