Update to use the new MathExtras.h support for log2 computation.
Patch contributed by Jim Laskey!
llvm-svn: 22594
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 530422d..e45e708e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -16,6 +16,7 @@
#include "llvm/GlobalValue.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetLowering.h"
#include <iostream>
#include <set>
@@ -45,15 +46,6 @@
}
}
-static unsigned ExactLog2(uint64_t Val) {
- unsigned Count = 0;
- while (Val != 1) {
- Val >>= 1;
- ++Count;
- }
- return Count;
-}
-
// isInvertibleForFree - Return true if there is no cost to emitting the logical
// inverse of this node.
static bool isInvertibleForFree(SDOperand N) {
@@ -527,7 +519,7 @@
// Perform the xform if the AND RHS is a single bit.
if ((AndRHS->getValue() & (AndRHS->getValue()-1)) == 0) {
return getNode(ISD::SRL, VT, N1,
- getConstant(ExactLog2(AndRHS->getValue()),
+ getConstant(Log2_64(AndRHS->getValue()),
TLI.getShiftAmountTy()));
}
} else if (Cond == ISD::SETEQ && C2 == AndRHS->getValue()) {
@@ -535,7 +527,7 @@
// Perform the xform if C2 is a single bit.
if ((C2 & (C2-1)) == 0) {
return getNode(ISD::SRL, VT, N1,
- getConstant(ExactLog2(C2),TLI.getShiftAmountTy()));
+ getConstant(Log2_64(C2),TLI.getShiftAmountTy()));
}
}
}
@@ -956,7 +948,7 @@
// FIXME: Move this to the DAG combiner when it exists.
if ((C2 & C2-1) == 0) {
- SDOperand ShAmt = getConstant(ExactLog2(C2), TLI.getShiftAmountTy());
+ SDOperand ShAmt = getConstant(Log2_64(C2), TLI.getShiftAmountTy());
return getNode(ISD::SHL, VT, N1, ShAmt);
}
break;
@@ -974,7 +966,7 @@
case ISD::UDIV:
// FIXME: Move this to the DAG combiner when it exists.
if ((C2 & C2-1) == 0 && C2) {
- SDOperand ShAmt = getConstant(ExactLog2(C2), TLI.getShiftAmountTy());
+ SDOperand ShAmt = getConstant(Log2_64(C2), TLI.getShiftAmountTy());
return getNode(ISD::SRL, VT, N1, ShAmt);
}
break;
@@ -1410,7 +1402,7 @@
// exists.
if (ConstantSDNode *AC = dyn_cast<ConstantSDNode>(N2))
if ((AC->getValue() & (AC->getValue()-1)) == 0) {
- unsigned ShCtV = ExactLog2(AC->getValue());
+ unsigned ShCtV = Log2_64(AC->getValue());
ShCtV = MVT::getSizeInBits(XType)-ShCtV-1;
SDOperand ShCt = getConstant(ShCtV, TLI.getShiftAmountTy());
SDOperand Shift = getNode(ISD::SRL, XType,