ARM64: Share address computation across SIMD LDRs/STRs.

For array accesses the element address has the following structure:
Address = CONST_OFFSET + base_addr + index << ELEM_SHIFT

Taking into account ARM64 LDR/STR addressing modes address part
(CONST_OFFSET + index << ELEM_SHIFT) can be shared across array
access with the same data type and index.

For example, for the following loop 5 accesses can share address
computation:

void foo(int[] a, int[] b, int[] c) {
  for (i...) {
    a[i] = a[i] + 5;
    b[i] = b[i] + c[i];
  }
}

Test: test-art-host, test-art-target

Change-Id: I46af3b4e4a55004336672cdba3296b7622d815ca

1 files changed, 2 insertions, 0 deletions

diff --git a/compiler/optimizing/instruction_simplifier_arm64.h b/compiler/optimizing/instruction_simplifier_arm64.h
index eec4e49792..8596f6ad40 100644
--- a/compiler/optimizing/instruction_simplifier_arm64.h
+++ b/compiler/optimizing/instruction_simplifier_arm64.h
@@ -75,6 +75,8 @@ class InstructionSimplifierArm64Visitor : public HGraphVisitor {
   void VisitUShr(HUShr* instruction) OVERRIDE;
   void VisitXor(HXor* instruction) OVERRIDE;
   void VisitVecMul(HVecMul* instruction) OVERRIDE;
+  void VisitVecLoad(HVecLoad* instruction) OVERRIDE;
+  void VisitVecStore(HVecStore* instruction) OVERRIDE;
 
   OptimizingCompilerStats* stats_;
 };