ARM64: Use the shifter operands.

This introduces architecture-specific instruction simplification.
On ARM64 we try to merge shifts and sign-extension operations into
arithmetic and logical instructions.

For example for the Java code

    int res = a + (b << 5);

we would generate

    lsl w3, w2, #5
    add w0, w1, w3

and we now generate

    add w0, w1, w2, lsl #5

Change-Id: Ic03bdff44a1c12e21ddff1b0513bd32a730742b7

1 files changed, 15 insertions, 0 deletions

diff --git a/compiler/optimizing/instruction_simplifier_arm64.h b/compiler/optimizing/instruction_simplifier_arm64.h
index eed2276588..b7f490bb8c 100644
--- a/compiler/optimizing/instruction_simplifier_arm64.h
+++ b/compiler/optimizing/instruction_simplifier_arm64.h
@@ -39,6 +39,17 @@ class InstructionSimplifierArm64Visitor : public HGraphVisitor {
                                     HInstruction* array,
                                     HInstruction* index,
                                     int access_size);
+  bool TryMergeIntoUsersShifterOperand(HInstruction* instruction);
+  bool TryMergeIntoShifterOperand(HInstruction* use,
+                                  HInstruction* bitfield_op,
+                                  bool do_merge);
+  bool CanMergeIntoShifterOperand(HInstruction* use, HInstruction* bitfield_op) {
+    return TryMergeIntoShifterOperand(use, bitfield_op, false);
+  }
+  bool MergeIntoShifterOperand(HInstruction* use, HInstruction* bitfield_op) {
+    DCHECK(CanMergeIntoShifterOperand(use, bitfield_op));
+    return TryMergeIntoShifterOperand(use, bitfield_op, true);
+  }
 
   bool TrySimpleMultiplyAccumulatePatterns(HMul* mul,
                                            HBinaryOperation* input_binop,
@@ -48,6 +59,10 @@ class InstructionSimplifierArm64Visitor : public HGraphVisitor {
   void VisitArrayGet(HArrayGet* instruction) OVERRIDE;
   void VisitArraySet(HArraySet* instruction) OVERRIDE;
   void VisitMul(HMul* instruction) OVERRIDE;
+  void VisitShl(HShl* instruction) OVERRIDE;
+  void VisitShr(HShr* instruction) OVERRIDE;
+  void VisitTypeConversion(HTypeConversion* instruction) OVERRIDE;
+  void VisitUShr(HUShr* instruction) OVERRIDE;
 
   OptimizingCompilerStats* stats_;
 };