Revert "[CloneFunction] Don't remove side effecting calls"

This reverts commit r277611 and the followup r277614.

Bootstrap builds and chromium builds are crashing during inlining after
this change.

llvm-svn: 277642

llvm/lib/Analysis/InstructionSimplify.cpp

@@ -4356,8 +4356,7 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
 
     // Gracefully handle edge cases where the instruction is not wired into any
     // parent block.
-    if (I->getParent() && !I->isEHPad() && !isa<TerminatorInst>(I) &&
-        !I->mayHaveSideEffects())
+    if (I->getParent())
       I->eraseFromParent();
   } else {
     Worklist.insert(I);
@@ -4385,8 +4384,7 @@ static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
 
     // Gracefully handle edge cases where the instruction is not wired into any
     // parent block.
-    if (I->getParent() && !I->isEHPad() && !isa<TerminatorInst>(I) &&
-        !I->mayHaveSideEffects())
+    if (I->getParent())
       I->eraseFromParent();
   }
   return Simplified;

llvm/lib/Transforms/Utils/CloneFunction.cpp

@@ -14,7 +14,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Utils/Cloning.h"
-#include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstructionSimplify.h"
@@ -553,39 +552,9 @@ void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
   // two PHINodes, the iteration over the old PHIs remains valid, and the
   // mapping will just map us to the new node (which may not even be a PHI
   // node).
-  const DataLayout &DL = NewFunc->getParent()->getDataLayout();
-  SmallSetVector<const Value *, 8> Worklist;
   for (unsigned Idx = 0, Size = PHIToResolve.size(); Idx != Size; ++Idx)
-    if (isa<PHINode>(VMap[PHIToResolve[Idx]]))
-      Worklist.insert(PHIToResolve[Idx]);
-
-  // Note that we must test the size on each iteration, the worklist can grow.
-  for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
-    const Value *OrigV = Worklist[Idx];
-    auto *I = cast_or_null<Instruction>(VMap.lookup(OrigV));
-    if (!I)
-      continue;
-
-    // See if this instruction simplifies.
-    Value *SimpleV = SimplifyInstruction(I, DL);
-    if (!SimpleV)
-      continue;
-
-    // Stash away all the uses of the old instruction so we can check them for
-    // recursive simplifications after a RAUW. This is cheaper than checking all
-    // uses of To on the recursive step in most cases.
-    for (const User *U : OrigV->users())
-      Worklist.insert(cast<Instruction>(U));
-
-    // Replace the instruction with its simplified value.
-    I->replaceAllUsesWith(SimpleV);
-
-    // If the original instruction had no side effects, remove it.
-    if (isInstructionTriviallyDead(I))
-      I->eraseFromParent();
-    else
-      VMap[OrigV] = I;
-  }
+    if (PHINode *PN = dyn_cast<PHINode>(VMap[PHIToResolve[Idx]]))
+      recursivelySimplifyInstruction(PN);
 
   // Now that the inlined function body has been fully constructed, go through
   // and zap unconditional fall-through branches. This happens all the time when

llvm/test/Transforms/Inline/inline_constprop.ll

@@ -279,25 +279,3 @@ return:
   %retval.0 = phi i32* [ %b, %if.end3 ], [ %a, %if.then ]
   ret i32* %retval.0
 }
-
-declare i32 @PR28802.external(i32 returned %p1)
-
-define internal i32 @PR28802.callee() {
-entry:
-  br label %cont
-
-cont:
-  %0 = phi i32 [ 0, %entry ]
-  %call = call i32 @PR28802.external(i32 %0)
-  ret i32 %call
-}
-
-define i32 @PR28802() {
-entry:
-  %call = call i32 @PR28802.callee()
-  ret i32 %call
-}
-
-; CHECK-LABEL: define i32 @PR28802(
-; CHECK: call i32 @PR28802.external(i32 0)
-; CHECK: ret i32 0