to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
Add a target option AllowRegisterRenaming that is used to opt in to
post-register-allocation renaming of registers. This is set to 0 by
default, which causes the hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq
fields of all opcodes to be set to 1, causing
MachineOperand::isRenamable to always return false.
Set the AllowRegisterRenaming flag to 1 for all in-tree targets that
have lit tests that were effected by enabling COPY forwarding in
MachineCopyPropagation (AArch64, AMDGPU, ARM, Hexagon, Mips, PowerPC,
RISCV, Sparc, SystemZ and X86).
Add some more comments describing the semantics of the
MachineOperand::isRenamable function and how it is set and maintained.
Change isRenamable to check the operand's opcode
hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq bit directly instead of
relying on it being consistently reflected in the IsRenamable bit
setting.
Clear the IsRenamable bit when changing an operand's register value.
Remove target code that was clearing the IsRenamable bit when changing
registers/opcodes now that this is done conservatively by default.
Change setting of hasExtraSrcRegAllocReq in AMDGPU target to be done in
one place covering all opcodes that have constant pipe read limit
restrictions.
Reviewers: qcolombet, MatzeB
Subscribers: aemerson, arsenm, jyknight, mcrosier, sdardis, nhaehnle, javed.absar, tpr, arichardson, kristof.beyls, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, escha, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D43042
llvm-svn: 325931
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Defining nodes should not alias with one another, while clobbering
nodes can. When pushing defs on stacks, push clobbers first, link
non-clobbering defs, then push the defs.
The data flow in a statement is now: uses -> clobbers -> defs.
llvm-svn: 295356
Use PackedRegisterRef to store the register information in the graph nodes.
This commit also removes support for virtual registers. It has never been
tested or used. It will be possible to add it back if there is a need.
llvm-svn: 284255
This is a very limited implementation of DFG-based copy propagation.
It only handles actual COPY instructions (does not handle other equivalents
such as add-immediate with a 0 operand).
The major limitation is that it does not update the DFG: that will be the
change required to make it more robust (hopefully coming up soon).
llvm-svn: 257490
Daniel Sanders