Revert r323738; that was not the one I wanted to merge

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_60@323739 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 4 insertions, 89 deletions

diff --git a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 7b898a3943d5..8f468ebf8949 100644
--- a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -14,7 +14,6 @@
 #include "llvm/Transforms/Scalar/CorrelatedValuePropagation.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/Optional.h"
-#include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/GlobalsModRef.h"
@@ -121,8 +120,8 @@ static bool processSelect(SelectInst *S, LazyValueInfo *LVI) {
   return true;
 }
 
-static bool processPHI(PHINode *P, LazyValueInfo *LVI, const SimplifyQuery &SQ,
-                       DenseSet<BasicBlock *> &ReachableBlocks) {
+static bool processPHI(PHINode *P, LazyValueInfo *LVI,
+                       const SimplifyQuery &SQ) {
   bool Changed = false;
 
   BasicBlock *BB = P->getParent();
@@ -130,18 +129,7 @@ static bool processPHI(PHINode *P, LazyValueInfo *LVI, const SimplifyQuery &SQ,
     Value *Incoming = P->getIncomingValue(i);
     if (isa<Constant>(Incoming)) continue;
 
-    // If the incoming value is coming from an unreachable block, replace
-    // it with undef and go on. This is good for two reasons:
-    // 1) We skip an LVI query for an unreachable block
-    // 2) We transform the incoming value so that the code below doesn't
-    //    mess around with IR in unreachable blocks.
-    BasicBlock *IncomingBB = P->getIncomingBlock(i);
-    if (!ReachableBlocks.count(IncomingBB)) {
-      P->setIncomingValue(i, UndefValue::get(P->getType()));
-      continue;
-    }
-
-    Value *V = LVI->getConstantOnEdge(Incoming, IncomingBB, BB, P);
+    Value *V = LVI->getConstantOnEdge(Incoming, P->getIncomingBlock(i), BB, P);
 
     // Look if the incoming value is a select with a scalar condition for which
     // LVI can tells us the value. In that case replace the incoming value with
@@ -573,14 +561,6 @@ static Constant *getConstantAt(Value *V, Instruction *At, LazyValueInfo *LVI) {
 
 static bool runImpl(Function &F, LazyValueInfo *LVI, const SimplifyQuery &SQ) {
   bool FnChanged = false;
-
-  // Compute reachability from the entry block of this function via an RPO
-  // walk. We use this information when processing PHIs.
-  DenseSet<BasicBlock *> ReachableBlocks;
-  ReversePostOrderTraversal<Function *> RPOT(&F);
-  for (BasicBlock *BB : RPOT)
-    ReachableBlocks.insert(BB);
-
   // Visiting in a pre-order depth-first traversal causes us to simplify early
   // blocks before querying later blocks (which require us to analyze early
   // blocks).  Eagerly simplifying shallow blocks means there is strictly less
@@ -595,7 +575,7 @@ static bool runImpl(Function &F, LazyValueInfo *LVI, const SimplifyQuery &SQ) {
         BBChanged |= processSelect(cast<SelectInst>(II), LVI);
         break;
       case Instruction::PHI:
-        BBChanged |= processPHI(cast<PHINode>(II), LVI, SQ, ReachableBlocks);
+        BBChanged |= processPHI(cast<PHINode>(II), LVI, SQ);
         break;
       case Instruction::ICmp:
       case Instruction::FCmp:
diff --git a/test/Transforms/CorrelatedValuePropagation/pr35807.ll b/test/Transforms/CorrelatedValuePropagation/pr35807.ll
deleted file mode 100644
index 8f72b596d281..000000000000
--- a/test/Transforms/CorrelatedValuePropagation/pr35807.ll
+++ /dev/null
@@ -1,65 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -correlated-propagation -S %s | FileCheck %s
-
-target triple = "x86_64-apple-darwin17.4.0"
-
-define void @patatino() {
-; CHECK-LABEL: @patatino(
-; CHECK-NEXT:    br i1 undef, label [[BB3:%.*]], label [[BB4:%.*]]
-; CHECK:       bb3:
-; CHECK-NEXT:    br label [[BB3]]
-; CHECK:       bb4:
-; CHECK-NEXT:    br i1 undef, label [[BB40:%.*]], label [[BB22:%.*]]
-; CHECK:       bb7:
-; CHECK-NEXT:    br label [[BB14:%.*]]
-; CHECK:       bb12:
-; CHECK-NEXT:    br label [[BB14]]
-; CHECK:       bb14:
-; CHECK-NEXT:    [[TMP19:%.*]] = icmp sgt i32 undef, undef
-; CHECK-NEXT:    [[TMP20:%.*]] = select i1 [[TMP19]], i64 [[TMP20]], i64 0
-; CHECK-NEXT:    br i1 undef, label [[BB40]], label [[BB7:%.*]]
-; CHECK:       bb22:
-; CHECK-NEXT:    br label [[BB24:%.*]]
-; CHECK:       bb24:
-; CHECK-NEXT:    br label [[BB32:%.*]]
-; CHECK:       bb32:
-; CHECK-NEXT:    br i1 undef, label [[BB40]], label [[BB24]]
-; CHECK:       bb40:
-; CHECK-NEXT:    ret void
-;
-  br i1 undef, label %bb3, label %bb4
-
-bb3:
-  br label %bb3
-
-bb4:
-  br i1 undef, label %bb40, label %bb22
-
-bb7:
-  br label %bb14
-
-bb12:
-  br label %bb14
-
-; This block is unreachable. Due to the non-standard definition of
-; dominance in LLVM where uses in unreachable blocks are dominated
-; by anything, it contains an instruction of the form
-; %def = OP %def, %something
-bb14:
-  %tmp19 = icmp sgt i32 undef, undef
-  %tmp20 = select i1 %tmp19, i64 %tmp20, i64 0
-  br i1 undef, label %bb40, label %bb7
-
-bb22:
-  br label %bb24
-
-bb24:
-  br label %bb32
-
-bb32:
-  br i1 undef, label %bb40, label %bb24
-
-bb40:
-  %tmp41 = phi i64 [ 4, %bb4 ], [ %tmp20, %bb14 ], [ undef, %bb32 ]
-  ret void
-}