[llvm] r175621 - Move the SplatByte helper to APInt and generalize it a bit.

[Benjamin Kramer]

Author: d0k
Date: Wed Feb 20 07:00:06 2013
New Revision: 175621

URL: http://llvm.org/viewvc/llvm-project?rev=175621&view=rev
Log:
Move the SplatByte helper to APInt and generalize it a bit.

Modified:
    llvm/trunk/include/llvm/ADT/APInt.h
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    llvm/trunk/unittests/ADT/APIntTest.cpp

Modified: llvm/trunk/include/llvm/ADT/APInt.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/APInt.h?rev=175621&r1=175620&r2=175621&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/APInt.h (original)
+++ llvm/trunk/include/llvm/ADT/APInt.h Wed Feb 20 07:00:06 2013
@@ -505,6 +505,17 @@ public:
     return getAllOnesValue(numBits).lshr(numBits - loBitsSet);
   }
 
+  /// \brief Return a value containing V broadcasted over NewLen bits.
+  static APInt getSplat(unsigned NewLen, const APInt &V) {
+    assert(NewLen >= V.getBitWidth() && "Can't splat to smaller bit width!");
+
+    APInt Val = V.zextOrSelf(NewLen);
+    for (unsigned I = V.getBitWidth(); I < NewLen; I <<= 1)
+      Val |= Val << I;
+
+    return Val;
+  }
+
   /// \brief Determine if two APInts have the same value, after zero-extending
   /// one of them (if needed!) to ensure that the bit-widths match.
   static bool isSameValue(const APInt &I1, const APInt &I2) {

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp?rev=175621&r1=175620&r2=175621&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp Wed Feb 20 07:00:06 2013
@@ -2539,18 +2539,6 @@ SDValue SelectionDAGLegalize::ExpandBSWA
   }
 }
 
-/// SplatByte - Distribute ByteVal over NumBits bits.
-// FIXME: Move this helper to a common place.
-static APInt SplatByte(unsigned NumBits, uint8_t ByteVal) {
-  APInt Val = APInt(NumBits, ByteVal);
-  unsigned Shift = 8;
-  for (unsigned i = NumBits; i > 8; i >>= 1) {
-    Val = (Val << Shift) | Val;
-    Shift <<= 1;
-  }
-  return Val;
-}
-
 /// ExpandBitCount - Expand the specified bitcount instruction into operations.
 ///
 SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
@@ -2568,10 +2556,10 @@ SDValue SelectionDAGLegalize::ExpandBitC
     // This is the "best" algorithm from
     // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
 
-    SDValue Mask55 = DAG.getConstant(SplatByte(Len, 0x55), VT);
-    SDValue Mask33 = DAG.getConstant(SplatByte(Len, 0x33), VT);
-    SDValue Mask0F = DAG.getConstant(SplatByte(Len, 0x0F), VT);
-    SDValue Mask01 = DAG.getConstant(SplatByte(Len, 0x01), VT);
+    SDValue Mask55 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x55)), VT);
+    SDValue Mask33 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x33)), VT);
+    SDValue Mask0F = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x0F)), VT);
+    SDValue Mask01 = DAG.getConstant(APInt::getSplat(Len, APInt(8, 0x01)), VT);
 
     // v = v - ((v >> 1) & 0x55555555...)
     Op = DAG.getNode(ISD::SUB, dl, VT, Op,

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=175621&r1=175620&r2=175621&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Wed Feb 20 07:00:06 2013
@@ -3377,17 +3377,6 @@ SDValue SelectionDAG::getStackArgumentTo
                  &ArgChains[0], ArgChains.size());
 }
 
-/// SplatByte - Distribute ByteVal over NumBits bits.
-static APInt SplatByte(unsigned NumBits, uint8_t ByteVal) {
-  APInt Val = APInt(NumBits, ByteVal);
-  unsigned Shift = 8;
-  for (unsigned i = NumBits; i > 8; i >>= 1) {
-    Val = (Val << Shift) | Val;
-    Shift <<= 1;
-  }
-  return Val;
-}
-
 /// getMemsetValue - Vectorized representation of the memset value
 /// operand.
 static SDValue getMemsetValue(SDValue Value, EVT VT, SelectionDAG &DAG,
@@ -3396,7 +3385,8 @@ static SDValue getMemsetValue(SDValue Va
 
   unsigned NumBits = VT.getScalarType().getSizeInBits();
   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Value)) {
-    APInt Val = SplatByte(NumBits, C->getZExtValue() & 255);
+    assert(C->getAPIntValue().getBitWidth() == 8);
+    APInt Val = APInt::getSplat(NumBits, C->getAPIntValue());
     if (VT.isInteger())
       return DAG.getConstant(Val, VT);
     return DAG.getConstantFP(APFloat(DAG.EVTToAPFloatSemantics(VT), Val), VT);
@@ -3406,7 +3396,7 @@ static SDValue getMemsetValue(SDValue Va
   if (NumBits > 8) {
     // Use a multiplication with 0x010101... to extend the input to the
     // required length.
-    APInt Magic = SplatByte(NumBits, 0x01);
+    APInt Magic = APInt::getSplat(NumBits, APInt(8, 0x01));
     Value = DAG.getNode(ISD::MUL, dl, VT, Value, DAG.getConstant(Magic, VT));
   }
 

Modified: llvm/trunk/unittests/ADT/APIntTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/APIntTest.cpp?rev=175621&r1=175620&r2=175621&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/APIntTest.cpp (original)
+++ llvm/trunk/unittests/ADT/APIntTest.cpp Wed Feb 20 07:00:06 2013
@@ -522,4 +522,14 @@ TEST(APIntTest, Rotate) {
   EXPECT_EQ(Rot, Big.rotr(144));
 }
 
+TEST(APIntTest, Splat) {
+  APInt ValA(8, 0x01);
+  EXPECT_EQ(ValA, APInt::getSplat(8, ValA));
+  EXPECT_EQ(APInt(64, 0x0101010101010101ULL), APInt::getSplat(64, ValA));
+
+  APInt ValB(3, 5);
+  EXPECT_EQ(APInt(4, 0xD), APInt::getSplat(4, ValB));
+  EXPECT_EQ(APInt(15, 0xDB6D), APInt::getSplat(15, ValB));
+}
+
 }