MachineRegisterInfo used to allow just one regalloc hint per virtual
register. This patch extends this to a vector of regalloc hints, which is
filled in by common code with sorted copy hints. Such hints will make for
more ID copies that can be removed.
NB! This improvement is currently (and hopefully temporarily) *disabled* by
default, except for SystemZ. The only reason for this is the big impact this
has on tests, which has unfortunately proven unmanageable. It was a long
while since all the tests were updated and just waiting for review (which
didn't happen), but now targets have to enable this themselves
instead. Several targets could get a head-start by downloading the tests
updates from the Phabricator review. Thanks to those who helped, and sorry
you now have to do this step yourselves.
This should be an improvement generally for any target!
The target may still create its own hint, in which case this has highest
priority and is stored first in the vector. If it has target-type, it will
not be recomputed, as per the previous behaviour.
The temporary hook enableMultipleCopyHints() will be removed as soon as all
targets return true.
Review: Quentin Colombet, Ulrich Weigand.
https://reviews.llvm.org/D38128
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319754 91177308-0d34-0410-b5e6-96231b3b80d8
The machine scheduler (before register allocation) is enabled by default for
SystemZ.
The SelectionDAG scheduling preference now becomes source order scheduling
(was regpressure).
Review: Ulrich Weigand
https://reviews.llvm.org/D37977
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315063 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In SelectionDAG, when a store is immediately chained to another store
to the same address, elide the first store as it has no observable
effects. This is causes small improvements dealing with intrinsics
lowered to stores.
Test notes:
* Many testcases overwrite store addresses multiple times and needed
minor changes, mainly making stores volatile to prevent the
optimization from optimizing the test away.
* Many X86 test cases optimized out instructions associated with
associated with va_start.
* Note that test_splat in CodeGen/AArch64/misched-stp.ll no longer has
dependencies to check and can probably be removed and potentially
replaced with another test.
Reviewers: rnk, john.brawn
Subscribers: aemerson, rengolin, qcolombet, jyknight, nemanjai, nhaehnle, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33206
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303198 91177308-0d34-0410-b5e6-96231b3b80d8
This combiner breaks debug experience and should not be run when optimizations are disabled.
For example:
int main() {
int j = 0;
j += 2;
if (j == 2)
return 0;
return 5;
}
When debugging this code compiled in /O0, it should be valid to break at line "j+=2;" and edit the value of j. It should change the return value of the function.
Differential Revision: https://reviews.llvm.org/D19268
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284014 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Port rL265480, rL264754, rL265997 and rL266252 to SystemZ, in order to enable the Swift port on the architecture. SwiftSelf and SwiftError are assigned to R10 and R9, respectively, which are normally callee-saved registers. For more information, see:
RFC: Implementing the Swift calling convention in LLVM and Clang
https://groups.google.com/forum/#!topic/llvm-dev/epDd2w93kZ0
Reviewers: kbarton, manmanren, rjmccall, uweigand
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D19414
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267823 91177308-0d34-0410-b5e6-96231b3b80d8
Jonas Paulsson