ArrayRef: Remove the equals helper with many arguments.

With initializer lists there is a really neat idiomatic way to write
this, 'ArrayRef.equals({1, 2, 3, 4, 5})'. Remove the equal method which
always had a hard limit on the number of arguments. I considered
rewriting it with variadic templates but that's not really a good fit
for a function with homogeneous arguments.

'ArrayRef == {1, 2, 3, 4, 5}' would've been even more awesome, but C++11
doesn't allow init lists with binary operators.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230907 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/ArrayRef.h

@@ -11,7 +11,6 @@
 #define LLVM_ADT_ARRAYREF_H
 
 #include "llvm/ADT/None.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include <vector>
 
@@ -44,19 +43,6 @@ namespace llvm {
     /// The number of elements.
     size_type Length;
 
-    /// \brief A dummy "optional" type that is only created by implicit
-    /// conversion from a reference to T.
-    ///
-    /// This type must *only* be used in a function argument or as a copy of
-    /// a function argument, as otherwise it will hold a pointer to a temporary
-    /// past that temporaries' lifetime.
-    struct TRefOrNothing {
-      const T *TPtr;
-
-      TRefOrNothing() : TPtr(nullptr) {}
-      TRefOrNothing(const T &TRef) : TPtr(&TRef) {}
-    };
-
   public:
     /// @name Constructors
     /// @{
@@ -201,47 +187,6 @@ namespace llvm {
       return std::vector<T>(Data, Data+Length);
     }
 
-    /// @}
-    /// @{
-    /// @name Convenience methods
-
-    /// @brief Predicate for testing that the array equals the exact sequence of
-    /// arguments.
-    ///
-    /// Will return false if the size is not equal to the exact number of
-    /// arguments given or if the array elements don't equal the argument
-    /// elements in order. Currently supports up to 16 arguments, but can
-    /// easily be extended.
-    bool equals(TRefOrNothing Arg0 = TRefOrNothing(),
-                TRefOrNothing Arg1 = TRefOrNothing(),
-                TRefOrNothing Arg2 = TRefOrNothing(),
-                TRefOrNothing Arg3 = TRefOrNothing(),
-                TRefOrNothing Arg4 = TRefOrNothing(),
-                TRefOrNothing Arg5 = TRefOrNothing(),
-                TRefOrNothing Arg6 = TRefOrNothing(),
-                TRefOrNothing Arg7 = TRefOrNothing(),
-                TRefOrNothing Arg8 = TRefOrNothing(),
-                TRefOrNothing Arg9 = TRefOrNothing(),
-                TRefOrNothing Arg10 = TRefOrNothing(),
-                TRefOrNothing Arg11 = TRefOrNothing(),
-                TRefOrNothing Arg12 = TRefOrNothing(),
-                TRefOrNothing Arg13 = TRefOrNothing(),
-                TRefOrNothing Arg14 = TRefOrNothing(),
-                TRefOrNothing Arg15 = TRefOrNothing()) {
-      TRefOrNothing Args[] = {Arg0,  Arg1,  Arg2,  Arg3, Arg4,  Arg5,
-                              Arg6,  Arg7,  Arg8,  Arg9, Arg10, Arg11,
-                              Arg12, Arg13, Arg14, Arg15};
-      if (size() > array_lengthof(Args))
-        return false;
-
-      for (unsigned i = 0, e = size(); i != e; ++i)
-        if (Args[i].TPtr == nullptr || (*this)[i] != *Args[i].TPtr)
-          return false;
-
-      // Either the size is exactly as many args, or the next arg must be null.
-      return size() == array_lengthof(Args) || Args[size()].TPtr == nullptr;
-    }
-
     /// @}
   };
 

lib/Target/X86/X86ISelLowering.cpp

@@ -19149,8 +19149,8 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
   //
   // FIXME: Should teach these routines about AVX vector widths.
   if (FloatDomain && VT.getSizeInBits() == 128) {
-    if (Mask.equals(0, 0) || Mask.equals(1, 1)) {
-      bool Lo = Mask.equals(0, 0);
+    if (Mask.equals({0, 0}) || Mask.equals({1, 1})) {
+      bool Lo = Mask.equals({0, 0});
       unsigned Shuffle;
       MVT ShuffleVT;
       // Check if we have SSE3 which will let us use MOVDDUP. That instruction
@@ -19179,8 +19179,8 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
       return true;
     }
     if (Subtarget->hasSSE3() &&
-        (Mask.equals(0, 0, 2, 2) || Mask.equals(1, 1, 3, 3))) {
-      bool Lo = Mask.equals(0, 0, 2, 2);
+        (Mask.equals({0, 0, 2, 2}) || Mask.equals({1, 1, 3, 3}))) {
+      bool Lo = Mask.equals({0, 0, 2, 2});
       unsigned Shuffle = Lo ? X86ISD::MOVSLDUP : X86ISD::MOVSHDUP;
       MVT ShuffleVT = MVT::v4f32;
       if (Depth == 1 && Root->getOpcode() == Shuffle)
@@ -19193,8 +19193,8 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
                     /*AddTo*/ true);
       return true;
     }
-    if (Mask.equals(0, 0, 1, 1) || Mask.equals(2, 2, 3, 3)) {
-      bool Lo = Mask.equals(0, 0, 1, 1);
+    if (Mask.equals({0, 0, 1, 1}) || Mask.equals({2, 2, 3, 3})) {
+      bool Lo = Mask.equals({0, 0, 1, 1});
       unsigned Shuffle = Lo ? X86ISD::UNPCKL : X86ISD::UNPCKH;
       MVT ShuffleVT = MVT::v4f32;
       if (Depth == 1 && Root->getOpcode() == Shuffle)
@@ -19213,11 +19213,11 @@ static bool combineX86ShuffleChain(SDValue Op, SDValue Root, ArrayRef<int> Mask,
   // variants as none of these have single-instruction variants that are
   // superior to the UNPCK formulation.
   if (!FloatDomain && VT.getSizeInBits() == 128 &&
-      (Mask.equals(0, 0, 1, 1, 2, 2, 3, 3) ||
-       Mask.equals(4, 4, 5, 5, 6, 6, 7, 7) ||
-       Mask.equals(0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7) ||
-       Mask.equals(8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15,
-                   15))) {
+      (Mask.equals({0, 0, 1, 1, 2, 2, 3, 3}) ||
+       Mask.equals({4, 4, 5, 5, 6, 6, 7, 7}) ||
+       Mask.equals({0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7}) ||
+       Mask.equals(
+           {8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15}))) {
     bool Lo = Mask[0] == 0;
     unsigned Shuffle = Lo ? X86ISD::UNPCKL : X86ISD::UNPCKH;
     if (Depth == 1 && Root->getOpcode() == Shuffle)
@@ -19706,7 +19706,7 @@ static SDValue PerformTargetShuffleCombine(SDValue N, SelectionDAG &DAG,
     // See if this reduces to a PSHUFD which is no more expensive and can
     // combine with more operations. Note that it has to at least flip the
     // dwords as otherwise it would have been removed as a no-op.
-    if (Mask[0] == 2 && Mask[1] == 3 && Mask[2] == 0 && Mask[3] == 1) {
+    if (makeArrayRef(Mask).equals({2, 3, 0, 1})) {
       int DMask[] = {0, 1, 2, 3};
       int DOffset = N.getOpcode() == X86ISD::PSHUFLW ? 0 : 2;
       DMask[DOffset + 0] = DOffset + 1;
@@ -19745,12 +19745,8 @@ static SDValue PerformTargetShuffleCombine(SDValue N, SelectionDAG &DAG,
         int MappedMask[8];
         for (int i = 0; i < 8; ++i)
           MappedMask[i] = 2 * DMask[WordMask[i] / 2] + WordMask[i] % 2;
-        const int UnpackLoMask[] = {0, 0, 1, 1, 2, 2, 3, 3};
-        const int UnpackHiMask[] = {4, 4, 5, 5, 6, 6, 7, 7};
-        if (std::equal(std::begin(MappedMask), std::end(MappedMask),
-                       std::begin(UnpackLoMask)) ||
-            std::equal(std::begin(MappedMask), std::end(MappedMask),
-                       std::begin(UnpackHiMask))) {
+        if (makeArrayRef(MappedMask).equals({0, 0, 1, 1, 2, 2, 3, 3}) ||
+            makeArrayRef(MappedMask).equals({4, 4, 5, 5, 6, 6, 7, 7})) {
           // We can replace all three shuffles with an unpack.
           V = DAG.getNode(ISD::BITCAST, DL, VT, D.getOperand(0));
           DCI.AddToWorklist(V.getNode());

unittests/ADT/ArrayRefTest.cpp

@@ -57,24 +57,24 @@ TEST(ArrayRefTest, DropBack) {
 TEST(ArrayRefTest, Equals) {
   static const int A1[] = {1, 2, 3, 4, 5, 6, 7, 8};
   ArrayRef<int> AR1(A1);
-  EXPECT_TRUE(AR1.equals(1, 2, 3, 4, 5, 6, 7, 8));
-  EXPECT_FALSE(AR1.equals(8, 1, 2, 4, 5, 6, 6, 7));
-  EXPECT_FALSE(AR1.equals(2, 4, 5, 6, 6, 7, 8, 1));
-  EXPECT_FALSE(AR1.equals(0, 1, 2, 4, 5, 6, 6, 7));
-  EXPECT_FALSE(AR1.equals(1, 2, 42, 4, 5, 6, 7, 8));
-  EXPECT_FALSE(AR1.equals(42, 2, 3, 4, 5, 6, 7, 8));
-  EXPECT_FALSE(AR1.equals(1, 2, 3, 4, 5, 6, 7, 42));
-  EXPECT_FALSE(AR1.equals(1, 2, 3, 4, 5, 6, 7));
-  EXPECT_FALSE(AR1.equals(1, 2, 3, 4, 5, 6, 7, 8, 9));
+  EXPECT_TRUE(AR1.equals({1, 2, 3, 4, 5, 6, 7, 8}));
+  EXPECT_FALSE(AR1.equals({8, 1, 2, 4, 5, 6, 6, 7}));
+  EXPECT_FALSE(AR1.equals({2, 4, 5, 6, 6, 7, 8, 1}));
+  EXPECT_FALSE(AR1.equals({0, 1, 2, 4, 5, 6, 6, 7}));
+  EXPECT_FALSE(AR1.equals({1, 2, 42, 4, 5, 6, 7, 8}));
+  EXPECT_FALSE(AR1.equals({42, 2, 3, 4, 5, 6, 7, 8}));
+  EXPECT_FALSE(AR1.equals({1, 2, 3, 4, 5, 6, 7, 42}));
+  EXPECT_FALSE(AR1.equals({1, 2, 3, 4, 5, 6, 7}));
+  EXPECT_FALSE(AR1.equals({1, 2, 3, 4, 5, 6, 7, 8, 9}));
 
   ArrayRef<int> AR1a = AR1.drop_back();
-  EXPECT_TRUE(AR1a.equals(1, 2, 3, 4, 5, 6, 7));
-  EXPECT_FALSE(AR1a.equals(1, 2, 3, 4, 5, 6, 7, 8));
+  EXPECT_TRUE(AR1a.equals({1, 2, 3, 4, 5, 6, 7}));
+  EXPECT_FALSE(AR1a.equals({1, 2, 3, 4, 5, 6, 7, 8}));
 
   ArrayRef<int> AR1b = AR1a.slice(2, 4);
-  EXPECT_TRUE(AR1b.equals(3, 4, 5, 6));
-  EXPECT_FALSE(AR1b.equals(2, 3, 4, 5, 6));
-  EXPECT_FALSE(AR1b.equals(3, 4, 5, 6, 7));
+  EXPECT_TRUE(AR1b.equals({3, 4, 5, 6}));
+  EXPECT_FALSE(AR1b.equals({2, 3, 4, 5, 6}));
+  EXPECT_FALSE(AR1b.equals({3, 4, 5, 6, 7}));
 }
 
 TEST(ArrayRefTest, EmptyEquals) {