Commit Graph

5 Commits

Author SHA1 Message Date
Matt Arsenault f9a42ed0a7 AMDGPU: Relax 32-bit SGPR register class
Mostly use SReg_32 instead of SReg_32_XM0 for arbitrary values. This
will allow the register coalescer to do a better job eliminating
copies to m0.

For GlobalISel, as a terrible hack, use SGPR_32 for things that should
use SCC until booleans are solved.

llvm-svn: 375267
2019-10-18 18:26:37 +00:00
David Stuttard 2d6a2303f8 [AMDGPU] Fix-up cases where writelane has 2 SGPR operands
Summary:
Even though writelane doesn't have the same constraints as other valu
instructions it still can't violate the >1 SGPR operand constraint

Due to later register propagation (e.g. fixing up vgpr operands via
readfirstlane) changing writelane to only have a single SGPR is tricky.

This implementation puts a new check after SIFixSGPRCopies that prevents
multiple SGPRs being used in any writelane instructions.

The algorithm used is to check for trivial copy prop of suitable constants into
one of the SGPR operands and perform that if possible. If this isn't possible
put an explicit copy of Src1 SGPR into M0 and use that instead (this is
allowable for writelane as the constraint is for SGPR read-port and not
constant-bus access).

Reviewers: rampitec, tpr, arsenm, nhaehnle

Reviewed By: rampitec, arsenm, nhaehnle

Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, mgorny, yaxunl, tpr, t-tye, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D51932

Change-Id: Ic7553fa57440f208d4dbc4794fc24345d7e0e9ea
llvm-svn: 375004
2019-10-16 14:37:39 +00:00
Matt Arsenault bb0a610599 AMDGPU: Fix capitalized register names in asm constraints
This was a workaround a long time ago, but the canonical lower case
names work now.

llvm-svn: 363459
2019-06-14 21:16:06 +00:00
Nicolai Haehnle 283b995097 AMDGPU: Fix getInstSizeInBytes
Summary:
Add some optional code to validate getInstSizeInBytes for emitted
instructions. This flushed out some issues which are fixed by this
patch:

- Streamline getInstSizeInBytes
- Properly define the VI readlane/writelane instruction as VOP3
- Fix the inline constant determination. Specifically, this change
  fixes an issue where a 32-bit value of 0xffffffff was recorded
  as unsigned. This is equal to -1 when restricting to a 32-bit
  comparison, and an inline constant can be used.

Reviewers: arsenm, rampitec

Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D50629

Change-Id: Id87c3b7975839da0de8156a124b0ce98c5fb47f2
llvm-svn: 340903
2018-08-29 07:46:09 +00:00
Tim Renouf 2a99fa2c08 [AMDGPU] added writelane intrinsic
Summary:
For use by LLPC SPV_AMD_shader_ballot extension.

The v_writelane instruction was already implemented for use by SGPR
spilling, but I had to add an extra dummy operand tied to the
destination, to represent that all lanes except the selected one keep
the old value of the destination register.

.ll test changes were due to schedule changes caused by that new
operand.

Differential Revision: https://reviews.llvm.org/D42838

llvm-svn: 326353
2018-02-28 19:10:32 +00:00