From bc6530574dcd0b5169fa737c93bbd49446afc8d0 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@gmail.com>
Date: Fri, 1 Jul 2016 06:54:51 +0000
Subject: [PATCH] [CodeGen] Cleanup getVectorShuffle a bit to take advantage of
 its new ArrayRef argument and its begin/end iterators. Also use 'int' type
 for number of elements and loop iterators to remove several typecasts. No
 functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274338 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 32 +++++++++++------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f5bb047f650..d87a8b9dce0 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1496,18 +1496,18 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1,
 
   // Validate that all indices in Mask are within the range of the elements
   // input to the shuffle.
-  unsigned NElts = VT.getVectorNumElements();
-  SmallVector<int, 8> MaskVec;
-  for (unsigned i = 0; i != NElts; ++i) {
-    assert(Mask[i] < (int)(NElts * 2) && "Index out of range");
-    MaskVec.push_back(Mask[i]);
-  }
+  int NElts = Mask.size();
+  assert(all_of(Mask, [&](int M) { return M < (NElts * 2); }) &&
+         "Index out of range");
+
+  // Copy the mask so we can do any needed cleanup.
+  SmallVector<int, 8> MaskVec(Mask.begin(), Mask.end());
 
   // Canonicalize shuffle v, v -> v, undef
   if (N1 == N2) {
     N2 = getUNDEF(VT);
-    for (unsigned i = 0; i != NElts; ++i)
-      if (MaskVec[i] >= (int)NElts) MaskVec[i] -= NElts;
+    for (int i = 0; i != NElts; ++i)
+      if (MaskVec[i] >= NElts) MaskVec[i] -= NElts;
   }
 
   // Canonicalize shuffle undef, v -> v, undef.  Commute the shuffle mask.
@@ -1522,8 +1522,8 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1,
     if (!Splat)
       return;
 
-    for (int i = 0; i < (int)NElts; ++i) {
-      if (MaskVec[i] < Offset || MaskVec[i] >= (Offset + (int)NElts))
+    for (int i = 0; i < NElts; ++i) {
+      if (MaskVec[i] < Offset || MaskVec[i] >= (Offset + NElts))
         continue;
 
       // If this input comes from undef, mark it as such.
@@ -1546,8 +1546,8 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1,
   // Canonicalize all index into rhs, -> shuffle rhs, undef
   bool AllLHS = true, AllRHS = true;
   bool N2Undef = N2.isUndef();
-  for (unsigned i = 0; i != NElts; ++i) {
-    if (MaskVec[i] >= (int)NElts) {
+  for (int i = 0; i != NElts; ++i) {
+    if (MaskVec[i] >= NElts) {
       if (N2Undef)
         MaskVec[i] = -1;
       else
@@ -1572,8 +1572,8 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1,
 
   // If Identity shuffle return that node.
   bool Identity = true, AllSame = true;
-  for (unsigned i = 0; i != NElts; ++i) {
-    if (MaskVec[i] >= 0 && MaskVec[i] != (int)i) Identity = false;
+  for (int i = 0; i != NElts; ++i) {
+    if (MaskVec[i] >= 0 && MaskVec[i] != i) Identity = false;
     if (MaskVec[i] != MaskVec[0]) AllSame = false;
   }
   if (Identity && NElts)
@@ -1629,7 +1629,7 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1,
   FoldingSetNodeID ID;
   SDValue Ops[2] = { N1, N2 };
   AddNodeIDNode(ID, ISD::VECTOR_SHUFFLE, getVTList(VT), Ops);
-  for (unsigned i = 0; i != NElts; ++i)
+  for (int i = 0; i != NElts; ++i)
     ID.AddInteger(MaskVec[i]);
 
   void* IP = nullptr;
@@ -1640,7 +1640,7 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, const SDLoc &dl, SDValue N1,
   // SDNode doesn't have access to it.  This memory will be "leaked" when
   // the node is deallocated, but recovered when the NodeAllocator is released.
   int *MaskAlloc = OperandAllocator.Allocate<int>(NElts);
-  memcpy(MaskAlloc, &MaskVec[0], NElts * sizeof(int));
+  std::copy(MaskVec.begin(), MaskVec.end(), MaskAlloc);
 
   auto *N = newSDNode<ShuffleVectorSDNode>(VT, dl.getIROrder(),
                                            dl.getDebugLoc(), MaskAlloc);
-- 
2.50.0