Commit Graph

3 Commits

Author SHA1 Message Date
David Green cf581d7977 [ARM] Always enable UseAA in the arm backend
This feature controls whether AA is used into the backend, and was
previously turned on for certain subtargets to help create less
constrained scheduling graphs. This patch turns it on for all
subtargets, so that they can all make use of the extra information to
produce better code.

Differential Revision: https://reviews.llvm.org/D69796
2019-11-05 10:46:56 +00:00
David Green d2d0f46cd2 [ARM] Cortex-M4 schedule
This patch adds a simple Cortex-M4 schedule, renaming the existing M3
schedule to M4 and filling in the latencies as-per the Cortex-M4 TRM:
https://developer.arm.com/docs/ddi0439/latest

Most of these are 1, with the important exception being loads taking 2
cycles. A few others are also higher, but I don't believe they make a
large difference. I've repurposed the M3 schedule as the latencies are
mostly the same between the two cores, with the M4 having more FP and
DSP instructions. We also turn on MISched and UseAA for the cores that
now use this.

It also adds some schedule Write's to various instruction to make things
simpler.

Differential Revision: https://reviews.llvm.org/D54142

llvm-svn: 360768
2019-05-15 12:41:58 +00:00
David Green 21a2973cc4 [ARM] Enable useAA() for the in-order Cortex-R52
This option allows codegen (such as DAGCombine or MI scheduling) to use alias
analysis information, which can help with the codegen on in-order cpu's,
especially machine scheduling. Here I have done things the same way as AArch64,
adding a subtarget feature to enable this for specific cores, and enabled it for
the R52 where we have a schedule to make use of it.

Differential Revision: https://reviews.llvm.org/D48074

llvm-svn: 335249
2018-06-21 15:48:29 +00:00