Add -disable-shifter-op to disable isel of shifter ops. On Cortex-a9 the shifts cost extra instructions so it might be better to emit them separately to take advantage of dual-issues.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109934 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-07-30 23:33:54 +00:00
parent 70a4e3c532
commit a2c519bd0b

View File

@ -36,6 +36,11 @@
using namespace llvm;
static cl::opt<bool>
DisableShifterOp("disable-shifter-op", cl::Hidden,
cl::desc("Disable isel of shifter-op"),
cl::init(false));
//===--------------------------------------------------------------------===//
/// ARMDAGToDAGISel - ARM specific code to select ARM machine
/// instructions for SelectionDAG operations.
@ -220,6 +225,9 @@ bool ARMDAGToDAGISel::SelectShifterOperandReg(SDNode *Op,
SDValue &BaseReg,
SDValue &ShReg,
SDValue &Opc) {
if (DisableShifterOp)
return false;
ARM_AM::ShiftOpc ShOpcVal = ARM_AM::getShiftOpcForNode(N);
// Don't match base register only case. That is matched to a separate
@ -666,6 +674,9 @@ bool ARMDAGToDAGISel::SelectThumbAddrModeSP(SDNode *Op, SDValue N,
bool ARMDAGToDAGISel::SelectT2ShifterOperandReg(SDNode *Op, SDValue N,
SDValue &BaseReg,
SDValue &Opc) {
if (DisableShifterOp)
return false;
ARM_AM::ShiftOpc ShOpcVal = ARM_AM::getShiftOpcForNode(N);
// Don't match base register only case. That is matched to a separate