[llvm-commits] [llvm] r109934 - /llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp

[Evan Cheng]

Author: evancheng
Date: Fri Jul 30 18:33:54 2010
New Revision: 109934

URL: http://llvm.org/viewvc/llvm-project?rev=109934&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp?rev=109934&r1=109933&r2=109934&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp Fri Jul 30 18:33:54 2010
@@ -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 @@
                                               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::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