[TargetLowering] Generalise BuildSDIV function

First step towards a BuildSDIV equivalent to D49248 for non-uniform vector support - this just pushes the splat detection down into TargetLowering::BuildSDIV where its still used.

Differential Revision: https://reviews.llvm.org/D50185

llvm-svn: 338838

1 files changed, 8 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index e317268fa5f..1b0818d3428 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -3463,8 +3463,8 @@ SDValue TargetLowering::BuildSDIVPow2(SDNode *N, const APInt &Divisor,
 /// return a DAG expression to select that will generate the same value by
 /// multiplying by a magic number.
 /// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
-SDValue TargetLowering::BuildSDIV(SDNode *N, const APInt &Divisor,
-                                  SelectionDAG &DAG, bool IsAfterLegalization,
+SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
+                                  bool IsAfterLegalization,
                                   SmallVectorImpl<SDNode *> &Created) const {
   EVT VT = N->getValueType(0);
   SDLoc dl(N);
@@ -3474,6 +3474,12 @@ SDValue TargetLowering::BuildSDIV(SDNode *N, const APInt &Divisor,
   if (!isTypeLegal(VT))
     return SDValue();
 
+  // TODO: Add non-uniform constant support.
+  ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
+  if (!C || C->isNullValue())
+    return SDValue();
+  const APInt &Divisor = C->getAPIntValue();
+
   // If the sdiv has an 'exact' bit we can use a simpler lowering.
   if (N->getFlags().hasExact())
     return BuildExactSDIV(*this, N->getOperand(0), Divisor, dl, DAG, Created);