ARM64: Instruction simplification for array accesses.
HArrayGet and HArraySet with variable indexes generate two
instructions on arm64, like
add temp, obj, #data_offset
ldr out, [temp, index LSL #shift_amount]
When we have multiple accesses to the same array, the initial `add`
instruction is redundant.
This patch introduces the first instruction simplification in the
arm64-specific instruction simplification pass. It splits HArrayGet
and HArraySet using the new arm64-specific IR HIntermediateAddress.
After that we run GVN again to squash the multiple occurrences of
HIntermediateAddress.
Change-Id: I2e3d12fbb07fed07b2cb2f3f47f99f5a032f8312
diff --git a/compiler/optimizing/instruction_simplifier_arm64.h b/compiler/optimizing/instruction_simplifier_arm64.h
index d7f4eae..4b697db 100644
--- a/compiler/optimizing/instruction_simplifier_arm64.h
+++ b/compiler/optimizing/instruction_simplifier_arm64.h
@@ -35,6 +35,14 @@
}
}
+ void TryExtractArrayAccessAddress(HInstruction* access,
+ HInstruction* array,
+ HInstruction* index,
+ int access_size);
+
+ void VisitArrayGet(HArrayGet* instruction) OVERRIDE;
+ void VisitArraySet(HArraySet* instruction) OVERRIDE;
+
OptimizingCompilerStats* stats_;
};