Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164768 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 07b6850..379a35a 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -2004,7 +2004,7 @@
           // LHS >u RHS.
           case ICmpInst::ICMP_UGT:
           case ICmpInst::ICMP_UGE:
-            // Comparison is true if the LHS <s 0.
+            // Comparison is true iff the LHS <s 0.
             if (MaxRecurse)
               if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
                                               Constant::getNullValue(SrcTy),
@@ -2013,7 +2013,7 @@
             break;
           case ICmpInst::ICMP_ULT:
           case ICmpInst::ICMP_ULE:
-            // Comparison is true if the LHS >=s 0.
+            // Comparison is true iff the LHS >=s 0.
             if (MaxRecurse)
               if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
                                               Constant::getNullValue(SrcTy),
@@ -2171,31 +2171,31 @@
   // Simplify comparisons involving max/min.
   Value *A, *B;
   CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
-  CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" if "A EqP B".
+  CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
 
   // Signed variants on "max(a,b)>=a -> true".
   if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
     if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
-    EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" if "A sge B".
+    EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
     // We analyze this as smax(A, B) pred A.
     P = Pred;
   } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
              (A == LHS || B == LHS)) {
     if (A != LHS) std::swap(A, B); // A pred smax(A, B).
-    EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" if "A sge B".
+    EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
     // We analyze this as smax(A, B) swapped-pred A.
     P = CmpInst::getSwappedPredicate(Pred);
   } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
              (A == RHS || B == RHS)) {
     if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
-    EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" if "A sle B".
+    EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
     // We analyze this as smax(-A, -B) swapped-pred -A.
     // Note that we do not need to actually form -A or -B thanks to EqP.
     P = CmpInst::getSwappedPredicate(Pred);
   } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
              (A == LHS || B == LHS)) {
     if (A != LHS) std::swap(A, B); // A pred smin(A, B).
-    EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" if "A sle B".
+    EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
     // We analyze this as smax(-A, -B) pred -A.
     // Note that we do not need to actually form -A or -B thanks to EqP.
     P = Pred;
@@ -2246,26 +2246,26 @@
   P = CmpInst::BAD_ICMP_PREDICATE;
   if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
     if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
-    EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" if "A uge B".
+    EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
     // We analyze this as umax(A, B) pred A.
     P = Pred;
   } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
              (A == LHS || B == LHS)) {
     if (A != LHS) std::swap(A, B); // A pred umax(A, B).
-    EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" if "A uge B".
+    EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
     // We analyze this as umax(A, B) swapped-pred A.
     P = CmpInst::getSwappedPredicate(Pred);
   } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
              (A == RHS || B == RHS)) {
     if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
-    EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" if "A ule B".
+    EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
     // We analyze this as umax(-A, -B) swapped-pred -A.
     // Note that we do not need to actually form -A or -B thanks to EqP.
     P = CmpInst::getSwappedPredicate(Pred);
   } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
              (A == LHS || B == LHS)) {
     if (A != LHS) std::swap(A, B); // A pred umin(A, B).
-    EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" if "A ule B".
+    EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
     // We analyze this as umax(-A, -B) pred -A.
     // Note that we do not need to actually form -A or -B thanks to EqP.
     P = Pred;
diff --git a/lib/Analysis/Interval.cpp b/lib/Analysis/Interval.cpp
index 125d42e..ca9cdca 100644
--- a/lib/Analysis/Interval.cpp
+++ b/lib/Analysis/Interval.cpp
@@ -27,7 +27,7 @@
 // isLoop - Find out if there is a back edge in this interval...
 //
 bool Interval::isLoop() const {
-  // There is a loop in this interval if one of the predecessors of the header
+  // There is a loop in this interval iff one of the predecessors of the header
   // node lives in the interval.
   for (::pred_iterator I = ::pred_begin(HeaderNode), E = ::pred_end(HeaderNode);
        I != E; ++I)
diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index d6dd627..ec618fa 100644
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -1109,14 +1109,14 @@
     // If this is an equality comparison, we can try to fold it knowing that
     // "V != C1".
     if (Pred == ICmpInst::ICMP_EQ) {
-      // !C1 == C -> false if C1 == C.
+      // !C1 == C -> false iff C1 == C.
       Res = ConstantFoldCompareInstOperands(ICmpInst::ICMP_NE,
                                             Result.getNotConstant(), C, TD,
                                             TLI);
       if (Res->isNullValue())
         return False;
     } else if (Pred == ICmpInst::ICMP_NE) {
-      // !C1 != C -> true if C1 == C.
+      // !C1 != C -> true iff C1 == C.
       Res = ConstantFoldCompareInstOperands(ICmpInst::ICMP_NE,
                                             Result.getNotConstant(), C, TD,
                                             TLI);
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index fe5860e..9b9c889 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1367,7 +1367,7 @@
 /// This form often exposes folding opportunities that are hidden in
 /// the original operand list.
 ///
-/// Return true if it appears that any interesting folding opportunities
+/// Return true iff it appears that any interesting folding opportunities
 /// may be exposed. This helps getAddRecExpr short-circuit extra work in
 /// the common case where no interesting opportunities are present, and
 /// is also used as a check to avoid infinite recursion.
@@ -5598,7 +5598,7 @@
 }
 
 /// SimplifyICmpOperands - Simplify LHS and RHS in a comparison with
-/// predicate Pred. Return true if any changes were made.
+/// predicate Pred. Return true iff any changes were made.
 ///
 bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred,
                                            const SCEV *&LHS, const SCEV *&RHS,
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 19fde0e..491224a 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -470,7 +470,7 @@
     return;
   }
   case Instruction::Shl:
-    // (shl X, C1) & C2 == 0   if   (X & C2 >>u C1) == 0
+    // (shl X, C1) & C2 == 0   iff   (X & C2 >>u C1) == 0
     if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
       uint64_t ShiftAmt = SA->getLimitedValue(BitWidth);
       ComputeMaskedBits(I->getOperand(0), KnownZero, KnownOne, TD, Depth+1);
@@ -482,7 +482,7 @@
     }
     break;
   case Instruction::LShr:
-    // (ushr X, C1) & C2 == 0   if  (-1 >> C1) & C2 == 0
+    // (ushr X, C1) & C2 == 0   iff  (-1 >> C1) & C2 == 0
     if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
       // Compute the new bits that are at the top now.
       uint64_t ShiftAmt = SA->getLimitedValue(BitWidth);
@@ -498,7 +498,7 @@
     }
     break;
   case Instruction::AShr:
-    // (ashr X, C1) & C2 == 0   if  (-1 >> C1) & C2 == 0
+    // (ashr X, C1) & C2 == 0   iff  (-1 >> C1) & C2 == 0
     if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
       // Compute the new bits that are at the top now.
       uint64_t ShiftAmt = SA->getLimitedValue(BitWidth-1);