Before I started maintaining the AVR backend, this instruction
never originally used to have an earlyclobber flag.
Some time afterwards (years ago), I must've added it back in, not realising that it
was left out for a reason.
This pseudo instrction exists solely to work around a long standing bug
in the register allocator.
Before this commit, the LDDWRdYQ pseudo was not actually working around
any bug. With the earlyclobber flag removed again, the LDDWRdYQ pseudo
now correctly works around PR13375 again.
llvm-svn: 326774
Summary: CPI does not read the status register, but only writes it.
Reviewers: dylanmckay
Reviewed By: dylanmckay
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33223
llvm-svn: 304116
Using arguments with attribute inalloca creates problems for verification
of machine representation. This attribute instructs the backend that the
argument is prepared in stack prior to CALLSEQ_START..CALLSEQ_END
sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size
stored in CALLSEQ_START in this case does not count the size of this
argument. However CALLSEQ_END still keeps total frame size, as caller can
be responsible for cleanup of entire frame. So CALLSEQ_START and
CALLSEQ_END keep different frame size and the difference is treated by
MachineVerifier as stack error. Currently there is no way to distinguish
this case from actual errors.
This patch adds additional argument to CALLSEQ_START and its
target-specific counterparts to keep size of stack that is set up prior to
the call frame sequence. This argument allows MachineVerifier to calculate
actual frame size associated with frame setup instruction and correctly
process the case of inalloca arguments.
The changes made by the patch are:
- Frame setup instructions get the second mandatory argument. It
affects all targets that use frame pseudo instructions and touched many
files although the changes are uniform.
- Access to frame properties are implemented using special instructions
rather than calls getOperand(N).getImm(). For X86 and ARM such
replacement was made previously.
- Changes that reflect appearance of additional argument of frame setup
instruction. These involve proper instruction initialization and
methods that access instruction arguments.
- MachineVerifier retrieves frame size using method, which reports sum of
frame parts initialized inside frame instruction pair and outside it.
The patch implements approach proposed by Quentin Colombet in
https://bugs.llvm.org/show_bug.cgi?id=27481#c1.
It fixes 9 tests failed with machine verifier enabled and listed
in PR27481.
Differential Revision: https://reviews.llvm.org/D32394
llvm-svn: 302527
We could previously select an integer which would hit an assertion error
in pseudo expansion.
The new type will also generate the appropriate fixups if needed, which
wasn't done beforehand.
llvm-svn: 289192
Dylan McKay