Preexisting waitcnt may not update the scoreboard if the instruction
being examined needed to wait on fewer counters than what was encoded in
the old waitcnt instruction. Fixing this results in the elimination of
some redudnat waitcnt.
These changes also enable combining consecutive waitcnt into a single
S_WAITCNT or S_WAITCNT_VSCNT instruction.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D100281
- Add "amdgpu-waitcnt-forcezero" to force all waitcnt instrs to be emitted as s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
- Add debug counters to control force emit of s_waitcnt instrs; debug counters:
si-insert-waitcnts-forceexp: force emit s_waitcnt expcnt(0) instrs
si-insert-waitcnts-forcevm: force emit s_waitcnt lgkmcnt(0) instrs
si-insert-waitcnts-forcelgkm: force emit s_waitcnt vmcnt(0) instrs
- Add some debug statements
Note that a variant of this patch was previously committed/reverted.
Differential Revision: https://reviews.llvm.org/D45888
llvm-svn: 330862
-amdgpu-waitcnt-forcezero={1|0} Force all waitcnt instrs to be emitted as s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-amdgpu-waitcnt-forceexp=<n> Force emit a s_waitcnt expcnt(0) before the first <n> instrs
-amdgpu-waitcnt-forcelgkm=<n> Force emit a s_waitcnt lgkmcnt(0) before the first <n> instrs
-amdgpu-waitcnt-forcevm=<n> Force emit a s_waitcnt vmcnt(0) before the first <n> instrs
This patch was pushed ( abb190fd51cd2f9a9eef08c024e109f7f7e909fc ), which caused a buildbot failure, reverted ( 6227480d74da507cf8e1b4bcaffbdb9fb875b4b8 ), and then updated to fix buildbot failures (this patch).
Differential Revision: https://reviews.llvm.org/D40091
llvm-svn: 323788
-amdgpu-waitcnt-forcezero={1|0} Force all waitcnt instrs to be emitted as s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-amdgpu-waitcnt-forceexp=<n> Force emit a s_waitcnt expcnt(0) before the first <n> instrs
-amdgpu-waitcnt-forcelgkm=<n> Force emit a s_waitcnt lgkmcnt(0) before the first <n> instrs
-amdgpu-waitcnt-forcevm=<n> Force emit a s_waitcnt vmcnt(0) before the first <n> instrs
Differential Revision: https://reviews.llvm.org/D40091
llvm-svn: 320084
