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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325931 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fix a few places that were modifying code after register
allocation to set the renamable bit correctly to avoid failing the
validation added in D42449.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323675 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM Coding Standards:
Function names should be verb phrases (as they represent actions), and
command-like function should be imperative. The name should be camel
case, and start with a lower case letter (e.g. openFile() or isFoo()).
Differential Revision: https://reviews.llvm.org/D40416
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319168 91177308-0d34-0410-b5e6-96231b3b80d8
If the register from the copy from exec was spilled,
the copy before the spill was deleted leaving a spill
of undefined register verifier error and miscompiling.
Check for other use instructions of the copy register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318132 91177308-0d34-0410-b5e6-96231b3b80d8
With SI_END_CF elimination for some nested control flow we can now
eliminate saved exec register completely by turning a saveexec version
of instruction into just a logical instruction.
Differential Revision: https://reviews.llvm.org/D36007
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309766 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
There was a bug with sequences like
s_mov_b64 s[0:1], exec
s_and_b64 s[2:3]<def>, s[0:1], s[2:3]<kill>
...
s_mov_b64_term exec, s[2:3]
because s[2:3] was defined and used in the same instruction, ending up with
SaveExecInst inside OtherUseInsts.
Note that the test case also exposes an unrelated bug.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98028
Reviewers: tstellarAMD, arsenm
Subscribers: kzhuravl, wdng, yaxunl, llvm-commits, tony-tye
Differential Revision: https://reviews.llvm.org/D25306
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283528 91177308-0d34-0410-b5e6-96231b3b80d8
Fixes to allow spilling all registers at the end of the block
work with exec modifications. Don't emit s_and_saveexec_b64 for
if lowering, and instead emit copies. Mark control flow mask
instructions as terminators to get correct spill code placement
with fast regalloc, and then have a separate optimization pass
form the saveexec.
This should work if SGPRs are spilled to VGPRs, but
will likely fail in the case that an SGPR spills to memory
and no workitem takes a divergent branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282667 91177308-0d34-0410-b5e6-96231b3b80d8
