Commit Graph

4 Commits

Author SHA1 Message Date
Matt Arsenault 1f795e2c2a GlobalISel: Enforce operand types for constants
A number of of tests were using imm operands, not cimm. Since CSE
relies on the exact ConstantInt* pointer used, and implicit
conversions are generally evil, also enforce the bitsize of the types.

llvm-svn: 353113
2019-02-04 23:29:31 +00:00
Matt Arsenault c765240060 AMDGPU/GlobalISel: Introduce vcc reg bank
I'm not entirely sure this is the correct thing
to do with the global isel philosophy, but I think
this is necessary to handle how differently SGPRs
are used normally vs. from a condition.

For example, it makes sense to allow a copy
from a VGPR to an SGPR, but it makes no sense
to allow a copy from VGPRs to SGPRs used as
select mask.

This avoids regbankselecting strange code with
a truncate feeding directly into a condition field.
Now a copy is forced from sgpr(s1) to vcc, which is
more sensible to handle.

Some of these issues could probably avoided with making enough
operations resulting in i1 illegal. I think we can't avoid
this register bank for legality.

For example, an i1 and where one source is from a truncate, and
one source is a compare needs some kind of copy inserted to
make sure both are in condition registers.

llvm-svn: 350611
2019-01-08 06:30:53 +00:00
Matt Arsenault ae6f1e07fc AMDGPU/GlobalISel: Disallow VGPR->SCC copies
This fixes using scalar adds when only the carry in is a VGPR
using greedy regbankselect.

llvm-svn: 350593
2019-01-08 01:13:20 +00:00
Matt Arsenault 68c668a5f3 AMDGPU/GlobalISel: RegBankSelect for carry-in
I'm not sure we should be allowing the truncate
to s1 for the inputs. It may be necessary to
create a new VCC reg bank.

llvm-svn: 350592
2019-01-08 01:09:09 +00:00