When we forward a stored value to a load and eliminate it entirely we need to
make sure the liveness of the register is maintained all the way to its use.
Previously we only cleared liveness on the store doing the forwarding, but
there could be other killing uses in between.
We already do the right thing when the load has to be converted into something
else, it was just this one path that skipped it.
llvm-svn: 306318
Summary:
This patch updates promoteLoadFromStore to use the store MachineOperand as the
source operand of the of the new instruction instead of creating a new
register MachineOperand. This way, the existing register flags are
preserved.
This fixes PR33468 (https://bugs.llvm.org/show_bug.cgi?id=33468).
Reviewers: MatzeB, t.p.northover, junbuml
Reviewed By: MatzeB
Subscribers: aemerson, rengolin, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D34402
llvm-svn: 305885
When promoting the Load of a Store-Load pair to a COPY all kill flags
between the store and the load need to be cleared.
rdar://30402435
Differential Revision: https://reviews.llvm.org/D30110
llvm-svn: 295512
Kill flags need to be updated correctly when moving stores up/down to
form store pair instructions.
Those invalid flags have been ignored before but as of r290014 they are
recognized when using -mllvm -verify-machineinstrs.
Also simplifies test/CodeGen/AArch64/ldst-opt-dbg-limit.mir, renames it
to ldst-opt.mir test and adds a new tests for this change.
Differential Revision: https://reviews.llvm.org/D28875
llvm-svn: 292625
Tim Northover