Commit Graph

10 Commits

Author SHA1 Message Date
Matt Arsenault fae05692a3 CodeGen: Print/parse LLTs in MachineMemOperands
This will currently accept the old number of bytes syntax, and convert
it to a scalar. This should be removed in the near future (I think I
converted all of the tests already, but likely missed a few).

Not sure what the exact syntax and policy should be. We can continue
printing the number of bytes for non-generic instructions to avoid
test churn and only allow non-scalar types for generic instructions.

This will currently print the LLT in parentheses, but accept parsing
the existing integers and implicitly converting to scalar. The
parentheses are a bit ugly, but the parser logic seems unable to deal
without either parentheses or some keyword to indicate the start of a
type.
2021-06-30 16:54:13 -04:00
Sjoerd Meijer 7efabe5c7d [MIR][ARM] MachineOperand comments
This adds infrastructure to print and parse MIR MachineOperand comments.
The motivation for the ARM backend is to print condition code names instead of
magic constants that are difficult to read (for human beings). For example,
instead of this:

  dead renamable $r2, $cpsr = tEOR killed renamable $r2, renamable $r1, 14, $noreg
  t2Bcc %bb.4, 0, killed $cpsr

we now print this:

  dead renamable $r2, $cpsr = tEOR killed renamable $r2, renamable $r1, 14 /* CC::always */, $noreg
  t2Bcc %bb.4, 0 /* CC:eq */, killed $cpsr

This shows that MachineOperand comments are enclosed between /* and */. In this
example, the EOR instruction is not conditionally executed (i.e. it is "always
executed"), which is encoded by the 14 immediate machine operand. Thus, now
this machine operand has /* CC::always */ as a comment. The 0 on the next
conditional branch instruction represents the equal condition code, thus now
this operand has /* CC:eq */ as a comment.

As it is a comment, the MI lexer/parser completely ignores it. The benefit is
that this keeps the change in the lexer extremely minimal and no target
specific parsing needs to be done. The changes on the MIPrinter side are also
minimal, as there is only one target hooks that is used to create the machine
operand comments.

Differential Revision: https://reviews.llvm.org/D74306
2020-02-24 14:19:21 +00:00
Puyan Lotfi 43e94b15ea Followup on Proposal to move MIR physical register namespace to '$' sigil.
Discussed here:

http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html

In preparation for adding support for named vregs we are changing the sigil for
physical registers in MIR to '$' from '%'. This will prevent name clashes of
named physical register with named vregs.

llvm-svn: 323922
2018-01-31 22:04:26 +00:00
Francis Visoiu Mistrih c71cced0aa [CodeGen] Always use `printReg` to print registers in both MIR and debug
output

As part of the unification of the debug format and the MIR format,
always use `printReg` to print all kinds of registers.

Updated the tests using '_' instead of '%noreg' until we decide which
one we want to be the default one.

Differential Revision: https://reviews.llvm.org/D40421

llvm-svn: 319445
2017-11-30 16:12:24 +00:00
Matthias Braun 537d039104 RegScavenging: Add scavengeRegisterBackwards()
Re-apply r276044/r279124/r305516. Fixed a problem where we would refuse
to place spills as the very first instruciton of a basic block and thus
artifically increase pressure (test in
test/CodeGen/PowerPC/scavenging.mir:spill_at_begin)

This is a variant of scavengeRegister() that works for
enterBasicBlockEnd()/backward(). The benefit of the backward mode is
that it is not affected by incomplete kill flags.

This patch also changes
PrologEpilogInserter::doScavengeFrameVirtualRegs() to use the register
scavenger in backwards mode.

Differential Revision: http://reviews.llvm.org/D21885

llvm-svn: 305625
2017-06-17 02:08:18 +00:00
Matthias Braun 35530d7129 Revert "RegScavenging: Add scavengeRegisterBackwards()"
Revert because of reports of some PPC input starting to spill when it
was predicted that it wouldn't and no spillslot was reserved.

This reverts commit r305516.

llvm-svn: 305566
2017-06-16 17:48:08 +00:00
Matthias Braun a42c537912 RegScavenging: Add scavengeRegisterBackwards()
Re-apply r276044/r279124. Trying to reproduce or disprove the ppc64
problems reported in the stage2 build last time, which I cannot
reproduce right now.

This is a variant of scavengeRegister() that works for
enterBasicBlockEnd()/backward(). The benefit of the backward mode is
that it is not affected by incomplete kill flags.

This patch also changes
PrologEpilogInserter::doScavengeFrameVirtualRegs() to use the register
scavenger in backwards mode.

Differential Revision: http://reviews.llvm.org/D21885

llvm-svn: 305516
2017-06-15 22:14:55 +00:00
Matthias Braun 8aaa368d00 ARMFrameLowering: Reserve emergency spill slot for large arguments
Re-commit after revert in r300668. Changed getMaxFPOffset() to a
more conservative heuristic instead of trying to be clever and missing
for some exotic calling conventions.

We need to reserve an emergency spill slot in cases with large argument
types that could overflow immediate offsets for FP relative address
calculations.

rdar://31317893

Differential Revision: https://reviews.llvm.org/D31643

llvm-svn: 300761
2017-04-19 21:11:44 +00:00
Renato Golin 742aed8683 Revert "ARMFrameLowering: Reserve emergency spill slot for large arguments"
This reverts commit r300639, as it broke self-hosting on ARM. PR32709.

llvm-svn: 300668
2017-04-19 09:02:52 +00:00
Matthias Braun 661d3d4b00 ARMFrameLowering: Reserve emergency spill slot for large arguments
We need to reserve an emergency spill slot in cases with large argument
types that could overflow immediate offsets for FP relative address
calculations.

rdar://31317893

Differential Revision: https://reviews.llvm.org/D31643

llvm-svn: 300639
2017-04-19 01:16:07 +00:00