commit 5cdbd20cc335f8bd4762e929b8c3658ee531318f
author Steve King <steve@metrokings.com> Tue Aug 25 02:31:21 2015 +0000
committer Steve King <steve@metrokings.com> Tue Aug 25 02:31:21 2015 +0000
tree faff8b1358d910919faab4bc7c2983b55e6a4d27
parent 9b33e28270a2796ed434de8c43ddb7d1a7daa5fa

Pass function attributes instead of boolean in isIntDivCheap().

llvm-svn: 245921

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index bd02b1e..3275daf 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2183,7 +2183,6 @@
                          N0, N1);
   }
 
-  bool MinSize = DAG.getMachineFunction().getFunction()->optForMinSize();
   // fold (sdiv X, pow2) -> simple ops after legalize
   // FIXME: We check for the exact bit here because the generic lowering gives
   // better results in that case. The target-specific lowering should learn how
@@ -2192,10 +2191,6 @@
       !cast<BinaryWithFlagsSDNode>(N)->Flags.hasExact() &&
       (N1C->getAPIntValue().isPowerOf2() ||
        (-N1C->getAPIntValue()).isPowerOf2())) {
-    // If integer division is cheap, then don't perform the following fold.
-    if (TLI.isIntDivCheap(N->getValueType(0), MinSize))
-      return SDValue();
-
     // Target-specific implementation of sdiv x, pow2.
     if (SDValue Res = BuildSDIVPow2(N))
       return Res;
@@ -2232,8 +2227,10 @@
   }
 
   // If integer divide is expensive and we satisfy the requirements, emit an
-  // alternate sequence.
-  if (N1C && !TLI.isIntDivCheap(N->getValueType(0), MinSize))
+  // alternate sequence.  Targets may check function attributes for size/speed
+  // trade-offs.
+  AttributeSet Attr = DAG.getMachineFunction().getFunction()->getAttributes();
+  if (N1C && !TLI.isIntDivCheap(N->getValueType(0), Attr))
     if (SDValue Op = BuildSDIV(N))
       return Op;
 
@@ -2289,8 +2286,8 @@
   }
 
   // fold (udiv x, c) -> alternate
-  bool MinSize = DAG.getMachineFunction().getFunction()->optForMinSize();
-  if (N1C && !TLI.isIntDivCheap(N->getValueType(0), MinSize))
+  AttributeSet Attr = DAG.getMachineFunction().getFunction()->getAttributes();
+  if (N1C && !TLI.isIntDivCheap(N->getValueType(0), Attr))
     if (SDValue Op = BuildUDIV(N))
       return Op;
 

llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index ffffaf0..88ace8f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2725,6 +2725,16 @@
   return Mul;
 }
 
+SDValue TargetLowering::BuildSDIVPow2(SDNode *N, const APInt &Divisor,
+                                      SelectionDAG &DAG,
+                                      std::vector<SDNode *> *Created) const {
+  AttributeSet Attr = DAG.getMachineFunction().getFunction()->getAttributes();
+  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
+  if (TLI.isIntDivCheap(N->getValueType(0), Attr))
+    return SDValue(N,0); // Lower SDIV as SDIV
+  return SDValue();
+}
+
 /// \brief Given an ISD::SDIV node expressing a divide by constant,
 /// return a DAG expression to select that will generate the same value by
 /// multiplying by a magic number.