RFR(M): 8154826: AArch64: take better advantage of base + shifted offset addressing mode

Roland Westrelin rwestrel at redhat.com
Thu Apr 21 08:23:31 UTC 2016


The aarch64 port implicitly transforms:
(AddP base (AddP base address (LShiftL index con)) offset)
(AddP base (AddP base offset) (LShiftL index con))
in the ad file to embed the shift (and possibly and i2l conversion) into
the addressing mode of a memory operation. Exposing that transformation
in the ideal graph allows:

- (AddP base offset) to be scheduled (for instance outside a loop)
- multiple identical (AddP base offset) to be commoned
- (LShiftL index con) to be cloned during matching so that each memory
access has its own


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