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/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 2598f4b..2931d2d 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -578,7 +578,7 @@
       return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
     }
     if (N0.hasOneUse()) {
-      // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) if x+c1 has one use
+      // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
       SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
                                    N0.getOperand(0), N1);
       AddToWorkList(OpNode.getNode());
@@ -596,7 +596,7 @@
       return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
     }
     if (N1.hasOneUse()) {
-      // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) if x+c1 has one use
+      // reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
       SDValue OpNode = DAG.getNode(Opc, N0.getDebugLoc(), VT,
                                    N1.getOperand(0), N0);
       AddToWorkList(OpNode.getNode());
@@ -1455,7 +1455,7 @@
   if (!VT.isVector() && SimplifyDemandedBits(SDValue(N, 0)))
     return SDValue(N, 0);
 
-  // fold (a+b) -> (a|b) if a and b share no bits.
+  // fold (a+b) -> (a|b) iff a and b share no bits.
   if (VT.isInteger() && !VT.isVector()) {
     APInt LHSZero, LHSOne;
     APInt RHSZero, RHSOne;
@@ -1549,7 +1549,7 @@
     return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
                                         N->getDebugLoc(), MVT::Glue));
 
-  // fold (addc a, b) -> (or a, b), CARRY_FALSE if a and b share no bits.
+  // fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
   APInt LHSZero, LHSOne;
   APInt RHSZero, RHSOne;
   DAG.ComputeMaskedBits(N0, LHSZero, LHSOne);
@@ -1937,7 +1937,7 @@
     return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0,
                        DAG.getConstant(N1C->getAPIntValue().logBase2(),
                                        getShiftAmountTy(N0.getValueType())));
-  // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) if c is power of 2
+  // fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
   if (N1.getOpcode() == ISD::SHL) {
     if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
       if (SHC->getAPIntValue().isPowerOf2()) {
@@ -2642,7 +2642,7 @@
       return SDValue(N, 0);   // Return N so it doesn't get rechecked!
     }
   }
-  // fold (zext_inreg (sextload x)) -> (zextload x) if load has one use
+  // fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
   if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
       N0.hasOneUse()) {
     LoadSDNode *LN0 = cast<LoadSDNode>(N0);
@@ -3038,7 +3038,7 @@
   // fold (or x, -1) -> -1
   if (N1C && N1C->isAllOnesValue())
     return N1;
-  // fold (or x, c) -> c if (x & ~c) == 0
+  // fold (or x, c) -> c iff (x & ~c) == 0
   if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
     return N1;
 
@@ -3055,7 +3055,7 @@
   if (ROR.getNode() != 0)
     return ROR;
   // Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
-  // if (c1 & c2) == 0.
+  // iff (c1 & c2) == 0.
   if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
              isa<ConstantSDNode>(N0.getOperand(1))) {
     ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
@@ -3392,7 +3392,7 @@
     return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, V);
   }
 
-  // fold (not (or x, y)) -> (and (not x), (not y)) if x or y are setcc
+  // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
   if (N1C && N1C->getAPIntValue() == 1 && VT == MVT::i1 &&
       (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
     SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
@@ -3404,7 +3404,7 @@
       return DAG.getNode(NewOpcode, N->getDebugLoc(), VT, LHS, RHS);
     }
   }
-  // fold (not (or x, y)) -> (and (not x), (not y)) if x or y are constants
+  // fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
   if (N1C && N1C->isAllOnesValue() &&
       (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
     SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
@@ -3882,7 +3882,7 @@
       return DAG.getNode(ISD::SRL, N->getDebugLoc(), VT, N0.getOperand(0), N1);
   }
 
-  // fold (srl (ctlz x), "5") -> x  if x has one bit set (the low bit).
+  // fold (srl (ctlz x), "5") -> x  iff x has one bit set (the low bit).
   if (N1C && N0.getOpcode() == ISD::CTLZ &&
       N1C->getAPIntValue() == Log2_32(VT.getSizeInBits())) {
     APInt KnownZero, KnownOne;
@@ -4816,7 +4816,7 @@
   if (N0.getOpcode() == ISD::TRUNCATE) {
     SDValue TruncOp = N0.getOperand(0);
     if (TruncOp.getValueType() == VT)
-      return TruncOp; // x if x size == zext size.
+      return TruncOp; // x iff x size == zext size.
     if (TruncOp.getValueType().bitsGT(VT))
       return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, TruncOp);
     return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, TruncOp);
@@ -5168,12 +5168,12 @@
     return NarrowLoad;
 
   // fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
-  // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) if possible.
+  // fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
   // We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
   if (N0.getOpcode() == ISD::SRL) {
     if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
       if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
-        // We can turn this into an SRA if the input to the SRL is already sign
+        // We can turn this into an SRA iff the input to the SRL is already sign
         // extended enough.
         unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
         if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
@@ -5199,7 +5199,7 @@
     CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
     return SDValue(N, 0);   // Return N so it doesn't get rechecked!
   }
-  // fold (sext_inreg (zextload x)) -> (sextload x) if load has one use
+  // fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
   if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
       N0.hasOneUse() &&
       EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
@@ -5506,7 +5506,7 @@
     }
   }
 
-  // bitconvert(build_pair(ld, ld)) -> ld if load locations are consecutive.
+  // bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
   if (N0.getOpcode() == ISD::BUILD_PAIR) {
     SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT);
     if (CombineLD.getNode())
@@ -6151,8 +6151,8 @@
 
   if (N1CFP) {
     const APFloat& V = N1CFP->getValueAPF();
-    // copysign(x, c1) -> fabs(x)       if ispos(c1)
-    // copysign(x, c1) -> fneg(fabs(x)) if isneg(c1)
+    // copysign(x, c1) -> fabs(x)       iff ispos(c1)
+    // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
     if (!V.isNegative()) {
       if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
         return DAG.getNode(ISD::FABS, N->getDebugLoc(), VT, N0);
@@ -8764,7 +8764,7 @@
     EVT XType = N0.getValueType();
     EVT AType = N2.getValueType();
     if (XType.bitsGE(AType)) {
-      // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" if A is a
+      // and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
       // single-bit constant.
       if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue()-1)) == 0)) {
         unsigned ShCtV = N2C->getAPIntValue().logBase2();
diff --git a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index d93b35d..1cccf1a 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -447,7 +447,7 @@
   if (ResNo == 1)
     return PromoteIntRes_Overflow(N);
 
-  // The operation overflowed if the result in the larger type is not the
+  // The operation overflowed iff the result in the larger type is not the
   // sign extension of its truncation to the original type.
   SDValue LHS = SExtPromotedInteger(N->getOperand(0));
   SDValue RHS = SExtPromotedInteger(N->getOperand(1));
@@ -610,7 +610,7 @@
   if (ResNo == 1)
     return PromoteIntRes_Overflow(N);
 
-  // The operation overflowed if the result in the larger type is not the
+  // The operation overflowed iff the result in the larger type is not the
   // zero extension of its truncation to the original type.
   SDValue LHS = ZExtPromotedInteger(N->getOperand(0));
   SDValue RHS = ZExtPromotedInteger(N->getOperand(1));
@@ -655,17 +655,17 @@
   }
   SDValue Mul = DAG.getNode(ISD::MUL, DL, LHS.getValueType(), LHS, RHS);
 
-  // Overflow occurred if the high part of the result does not
+  // Overflow occurred iff the high part of the result does not
   // zero/sign-extend the low part.
   SDValue Overflow;
   if (N->getOpcode() == ISD::UMULO) {
-    // Unsigned overflow occurred if the high part is non-zero.
+    // Unsigned overflow occurred iff the high part is non-zero.
     SDValue Hi = DAG.getNode(ISD::SRL, DL, Mul.getValueType(), Mul,
                              DAG.getIntPtrConstant(SmallVT.getSizeInBits()));
     Overflow = DAG.getSetCC(DL, N->getValueType(1), Hi,
                             DAG.getConstant(0, Hi.getValueType()), ISD::SETNE);
   } else {
-    // Signed overflow occurred if the high part does not sign extend the low.
+    // Signed overflow occurred iff the high part does not sign extend the low.
     SDValue SExt = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, Mul.getValueType(),
                                Mul, DAG.getValueType(SmallVT));
     Overflow = DAG.getSetCC(DL, N->getValueType(1), SExt, Mul, ISD::SETNE);
@@ -2240,8 +2240,8 @@
                             LHS, RHS);
   SplitInteger(Sum, Lo, Hi);
 
-  // Calculate the overflow: addition overflows if a + b < a, and subtraction
-  // overflows if a - b > a.
+  // Calculate the overflow: addition overflows iff a + b < a, and subtraction
+  // overflows iff a - b > a.
   SDValue Ofl = DAG.getSetCC(dl, N->getValueType(1), Sum, LHS,
                              N->getOpcode () == ISD::UADDO ?
                              ISD::SETULT : ISD::SETUGT);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 99d2aad..a48a625 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1825,7 +1825,7 @@
       KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1);
     return;
   case ISD::SHL:
-    // (shl X, C1) & C2 == 0   if   (X & C2 >>u C1) == 0
+    // (shl X, C1) & C2 == 0   iff   (X & C2 >>u C1) == 0
     if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
       unsigned ShAmt = SA->getZExtValue();
 
@@ -1842,7 +1842,7 @@
     }
     return;
   case ISD::SRL:
-    // (ushr X, C1) & C2 == 0   if  (-1 >> C1) & C2 == 0
+    // (ushr X, C1) & C2 == 0   iff  (-1 >> C1) & C2 == 0
     if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
       unsigned ShAmt = SA->getZExtValue();
 
@@ -2356,7 +2356,7 @@
 /// ISD::ADD with a ConstantSDNode on the right-hand side, or if it is an
 /// ISD::OR with a ConstantSDNode that is guaranteed to have the same
 /// semantics as an ADD.  This handles the equivalence:
-///     X|Cst == X+Cst if X&Cst = 0.
+///     X|Cst == X+Cst iff X&Cst = 0.
 bool SelectionDAG::isBaseWithConstantOffset(SDValue Op) const {
   if ((Op.getOpcode() != ISD::ADD && Op.getOpcode() != ISD::OR) ||
       !isa<ConstantSDNode>(Op.getOperand(1)))
@@ -2882,7 +2882,7 @@
     assert(VT.isFloatingPoint() && EVT.isFloatingPoint() &&
            "Cannot FP_ROUND_INREG integer types");
     assert(EVT.isVector() == VT.isVector() &&
-           "FP_ROUND_INREG type should be vector if the operand "
+           "FP_ROUND_INREG type should be vector iff the operand "
            "type is vector!");
     assert((!EVT.isVector() ||
             EVT.getVectorNumElements() == VT.getVectorNumElements()) &&
@@ -2918,7 +2918,7 @@
     assert(VT.isInteger() && EVT.isInteger() &&
            "Cannot *_EXTEND_INREG FP types");
     assert(EVT.isVector() == VT.isVector() &&
-           "SIGN_EXTEND_INREG type should be vector if the operand "
+           "SIGN_EXTEND_INREG type should be vector iff the operand "
            "type is vector!");
     assert((!EVT.isVector() ||
             EVT.getVectorNumElements() == VT.getVectorNumElements()) &&
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 5ed1c03..be3ecf3 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1330,7 +1330,7 @@
 
     // If all of the unknown bits are known to be zero on one side or the other
     // (but not both) turn this into an *inclusive* or.
-    //    e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) if C1&C2 == 0
+    //    e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
     if ((NewMask & ~KnownZero & ~KnownZero2) == 0)
       return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(),
                                                Op.getOperand(0),
@@ -1344,7 +1344,7 @@
     // If all of the demanded bits on one side are known, and all of the set
     // bits on that side are also known to be set on the other side, turn this
     // into an AND, as we know the bits will be cleared.
-    //    e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 if (C1&C2) == C2
+    //    e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
     // NB: it is okay if more bits are known than are requested
     if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known on one side 
       if (KnownOne == KnownOne2) { // set bits are the same on both sides
@@ -1970,7 +1970,7 @@
         return DAG.getSetCC(dl, VT, And, DAG.getConstant(0, CTVT), CC);
       }
 
-      // TODO: (ctpop x) == 1 -> x && (x & x-1) == 0 if ctpop is illegal.
+      // TODO: (ctpop x) == 1 -> x && (x & x-1) == 0 iff ctpop is illegal.
     }
 
     // (zext x) == C --> x == (trunc C)
@@ -2503,7 +2503,7 @@
                                 N0.getValueType()), Cond);
           }
 
-          // Turn (X^C1) == C2 into X == C1^C2 if X&~C1 = 0.
+          // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
           if (N0.getOpcode() == ISD::XOR)
             // If we know that all of the inverted bits are zero, don't bother
             // performing the inversion.