4 Commits

Author	SHA1	Message	Date
Eli Friedman	92d0d13366	[AArch64] Prefer "mov" over "orr" to materialize constants. ... This is generally more readable due to the way the assembler aliases work. (This causes a lot of test changes, but it's not really as scary as it looks at first glance; it's just mechanically changing a bunch of checks for orr to check for mov instead.) Differential Revision: https://reviews.llvm.org/D59720 llvm-svn: 356954	2019-03-25 21:25:28 +00:00
Matthias Braun	f29b12dca8	ScheduleDAGInstrs: Ignore dependencies of constant physregs ... There is no need to track dependencies for constant physregs, as they don't change their value no matter in what order you read/write to them. Differential Revision: https://reviews.llvm.org/D26221 llvm-svn: 286526	2016-11-10 23:46:44 +00:00
Matthias Braun	9d62c5571b	RegisterCoalescer: Ignore interferences for constant physregs ... When copying to/from a constant register interferences can be ignored. Also update the documentation for isConstantPhysReg() to make it more obvious that this transformation is valid. Differential Revision: https://reviews.llvm.org/D26106 llvm-svn: 286503	2016-11-10 21:22:47 +00:00
Ahmed Bougacha	54b7d334c7	[MachineCSE] Clear kill-flag on registers imp-def'd by the CSE'd instruction. ... Go through implicit defs of CSMI and MI, and clear the kill flags on their uses in all the instructions between CSMI and MI. We might have made some of the kill flags redundant, consider: subs ... %NZCV<imp-def> <- CSMI csinc ... %NZCV<imp-use,kill> <- this kill flag isn't valid anymore subs ... %NZCV<imp-def> <- MI, to be eliminated csinc ... %NZCV<imp-use,kill> Since we eliminated MI, and reused a register imp-def'd by CSMI (here %NZCV), that register, if it was killed before MI, should have that kill flag removed, because it's lifetime was extended. Also, add an exhaustive testcase for the motivating example. Reviewed by: Juergen Ributzka <juergen@apple.com> llvm-svn: 223133	2014-12-02 18:09:51 +00:00