Commit Graph

8 Commits

Author SHA1 Message Date
Sanjoy Das 4a8fe09040 [ImplicitNullCheck] Fix an edge case where we were hoisting incorrectly
ImplicitNullCheck keeps track of one instruction that the memory
operation depends on that it also hoists with the memory operation.
When hoisting this dependency, it would sometimes clobber a live-in
value to the basic block we were hoisting the two things out of.  Fix
this by explicitly looking for such dependencies.

I also noticed two redundant checks on `MO.isDef()` in IsMIOperandSafe.
They're redundant since register MachineOperands are either Defs or Uses
-- there is no third kind.  I'll change the checks to asserts in a later
commit.

llvm-svn: 287213
2016-11-17 07:29:40 +00:00
Sanjoy Das df4b162e4d [ImplicitNullChecks] Do not not handle call MachineInstrs
We don't track callee clobbered registers correctly, so avoid hoisting
across calls.

Note: for this bug to trigger we need a `readonly` call target, since we
already have logic to not hoist across potentially storing instructions
either.

llvm-svn: 287159
2016-11-16 21:45:22 +00:00
Matthias Braun 1eb473680a MachineFunctionProperties/MIRParser: Rename AllVRegsAllocated->NoVRegs, compute it
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.

Differential Revision: http://reviews.llvm.org/D23850

llvm-svn: 279698
2016-08-25 01:27:13 +00:00
Matthias Braun f1b20c5225 MachineRegisterInfo/MIR: Initialize tracksSubRegLiveness early, do not print/parser it
tracksSubRegLiveness only depends on the Subtarget and a cl::opt, there
is not need to change it or save/parse it in a .mir file.
Make the field const and move the initialization LiveIntervalAnalysis to the
MachineRegisterInfo constructor. Also cleanup some code and fix some
instances which better use MachineRegisterInfo::subRegLivenessEnabled() instead
of TargetSubtargetInfo::enableSubRegLiveness().

llvm-svn: 279676
2016-08-24 22:17:45 +00:00
Matthias Braun 79f85b3b8f MIRParser/MIRPrinter: Compute isSSA instead of printing/parsing it.
Specifying isSSA is an extra line at best and results in invalid MI at
worst. Compute the value instead.

Differential Revision: http://reviews.llvm.org/D22722

llvm-svn: 279600
2016-08-24 01:32:41 +00:00
Quentin Colombet 545e558b82 [MIR] Print on the given output instead of stderr.
Currently the MIR framework prints all its outputs (errors and actual
representation) on stderr.

This patch fixes that by printing the regular output in the output
specified with -o.

Differential Revision: http://reviews.llvm.org/D22251

llvm-svn: 275314
2016-07-13 20:36:03 +00:00
Tim Northover 1d106c5fc2 tests: accept different TargetOpcode values.
These tests don't actually care about the internal opcode number, but have to
be updated whenever we add a new one for GlobalISel. That's bad.

llvm-svn: 274774
2016-07-07 17:51:42 +00:00
Sanjoy Das e57bf680ec [ImplicitNullChecks] Hoist trivial depdendencies if possible
When trying to convert a loading instruction into a FAULTING_LOAD, we
sometimes face code like this:

  if %R10 is not null:
    %R9<def> = MOV32ri Immediate
    %R9<def, tied> = AND32rm %R9, 0x20(%R10)
  else:
    goto TRAP

In these cases we would like to use the AND32rm instruction as the
faulting operation by hoisting the "depedency" def-ing %R9 also above
the control flow, transforming the program into:

  %R9<def> = MOV32ri Immediate
  %R9<def, tied> = FAULTING_LOAD_OP(AND32rm %R9, 0x20(%R10), FailPath: TRAP)

This change teaches ImplicitNullChecks to do the above, when safe.

llvm-svn: 273501
2016-06-22 22:16:51 +00:00