Re-enable "[NFC] Unify guards detection"

rL340921 has been reverted by rL340923 due to linkage dependency
from Transform/Utils to Analysis which is not allowed. In this patch
this has been fixed, a new utility function moved to Analysis.

Differential Revision: https://reviews.llvm.org/D51152

llvm-svn: 341014
diff --git a/llvm/lib/Transforms/Scalar/EarlyCSE.cpp b/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
index 533d16e..fc14d8a 100644
--- a/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
+++ b/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
@@ -22,6 +22,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/GuardUtils.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
@@ -54,6 +55,7 @@
 #include "llvm/Support/RecyclingAllocator.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/GuardUtils.h"
 #include <cassert>
 #include <deque>
 #include <memory>
@@ -863,7 +865,7 @@
       continue;
     }
 
-    if (match(Inst, m_Intrinsic<Intrinsic::experimental_guard>())) {
+    if (isGuard(Inst)) {
       if (auto *CondI =
               dyn_cast<Instruction>(cast<CallInst>(Inst)->getArgOperand(0))) {
         if (SimpleValue::canHandle(CondI)) {
diff --git a/llvm/lib/Transforms/Scalar/GuardWidening.cpp b/llvm/lib/Transforms/Scalar/GuardWidening.cpp
index 68be46e..9106459 100644
--- a/llvm/lib/Transforms/Scalar/GuardWidening.cpp
+++ b/llvm/lib/Transforms/Scalar/GuardWidening.cpp
@@ -45,6 +45,7 @@
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/BranchProbabilityInfo.h"
+#include "llvm/Analysis/GuardUtils.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/PostDominators.h"
@@ -107,12 +108,6 @@
   cast<BranchInst>(I)->setCondition(NewCond);
 }
 
-// Whether or not the particular instruction \p I is a guard.
-static bool isGuard(const Instruction *I) {
-  using namespace llvm::PatternMatch;
-  return match(I, m_Intrinsic<Intrinsic::experimental_guard>());
-}
-
 // Eliminates the guard instruction properly.
 static void eliminateGuard(Instruction *GuardInst) {
   GuardInst->eraseFromParent();
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 39895dc..1fc8f39 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -25,6 +25,7 @@
 #include "llvm/Analysis/CFG.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/GuardUtils.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/LazyValueInfo.h"
 #include "llvm/Analysis/Loads.h"
@@ -2607,9 +2608,8 @@
 
   if (auto *BI = dyn_cast<BranchInst>(Parent->getTerminator()))
     for (auto &I : *BB)
-      if (match(&I, m_Intrinsic<Intrinsic::experimental_guard>()))
-        if (ThreadGuard(BB, cast<IntrinsicInst>(&I), BI))
-          return true;
+      if (isGuard(&I) && ThreadGuard(BB, cast<IntrinsicInst>(&I), BI))
+        return true;
 
   return false;
 }
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 470ae3e..dc0b6f5 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -38,6 +38,7 @@
 #include "llvm/Analysis/CaptureTracking.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/GuardUtils.h"
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
@@ -528,7 +529,7 @@
       using namespace PatternMatch;
       if (((I.use_empty() &&
             match(&I, m_Intrinsic<Intrinsic::invariant_start>())) ||
-           match(&I, m_Intrinsic<Intrinsic::experimental_guard>())) &&
+           isGuard(&I)) &&
           IsMustExecute && IsMemoryNotModified &&
           CurLoop->hasLoopInvariantOperands(&I)) {
         hoist(I, DT, CurLoop, SafetyInfo, ORE);
diff --git a/llvm/lib/Transforms/Scalar/LowerGuardIntrinsic.cpp b/llvm/lib/Transforms/Scalar/LowerGuardIntrinsic.cpp
index fac57014..4867b33 100644
--- a/llvm/lib/Transforms/Scalar/LowerGuardIntrinsic.cpp
+++ b/llvm/lib/Transforms/Scalar/LowerGuardIntrinsic.cpp
@@ -15,6 +15,7 @@
 
 #include "llvm/Transforms/Scalar/LowerGuardIntrinsic.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Analysis/GuardUtils.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/InstIterator.h"
@@ -49,10 +50,8 @@
 
   SmallVector<CallInst *, 8> ToLower;
   for (auto &I : instructions(F))
-    if (auto *CI = dyn_cast<CallInst>(&I))
-      if (auto *F = CI->getCalledFunction())
-        if (F->getIntrinsicID() == Intrinsic::experimental_guard)
-          ToLower.push_back(CI);
+    if (isGuard(&I))
+      ToLower.push_back(cast<CallInst>(&I));
 
   if (ToLower.empty())
     return false;