ART: Transform Sub+Sub into Sub+Add to merge Shl
In the instruction sequence like the following:
t1 = Shl(a, n)
t2 = Sub(t1, *)
r = Sub(*, t2)
Shl cannot be merged with Sub. However it can be done when the first Sub
operands are reordered and the second Sub is replaced with Add:
t1 = Shl(a, n)
t2 = Sub(*, t1)
r = Add(*, t2)
This CL implements this transformation in the ARM/ARM64 instruction simplifiers.
Test: 411-checker-instruct-simplifier-hrem
Test: test.py --host --optimizing --jit --gtest --interpreter
Test: test.py --target --optimizing --jit --interpreter
Test: run-gtests.sh
Change-Id: I24fde29d307f3ad53a8df8bbafe945b4f733ce6c
5 files changed
