diff options
| author | Petar Avramovic <Petar.Avramovic@amd.com> | 2023-10-04 13:58:47 +0200 |
|---|---|---|
| committer | Petar Avramovic <Petar.Avramovic@amd.com> | 2023-10-06 15:00:08 +0200 |
| commit | 2fa7d652d02ae5da0d32d63c4258705eadab1576 (patch) | |
| tree | e4357c0b510667a4da94b54f05a1f3389af865db /llvm/lib/CodeGen/MachineSink.cpp | |
| parent | 2d7fe90a3eb8b31bc02ee4407b3e74336ac729fc (diff) | |
| download | llvm-2fa7d652d02ae5da0d32d63c4258705eadab1576.zip llvm-2fa7d652d02ae5da0d32d63c4258705eadab1576.tar.gz llvm-2fa7d652d02ae5da0d32d63c4258705eadab1576.tar.bz2 | |
AMDGPU: Fix temporal divergence introduced by machine-sink (#67456)
Temporal divergence that was present in input or introduced in IR
transforms, like code-sinking or LICM, is handled in SIFixSGPRCopies
by changing sgpr source instr to vgpr instr.
After 5b657f5, that moved LICM after AMDGPUCodeGenPrepare,
machine-sinking can introduce temporal divergence by sinking
instructions outside of the cycle.
Add isSafeToSink callback in TargetInstrInfo.
Diffstat (limited to 'llvm/lib/CodeGen/MachineSink.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineSink.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp index 14de333..2d9ff33 100644 --- a/llvm/lib/CodeGen/MachineSink.cpp +++ b/llvm/lib/CodeGen/MachineSink.cpp @@ -735,6 +735,7 @@ bool MachineSinking::runOnMachineFunction(MachineFunction &MF) { MadeChange = true; ++NumSplit; + CI->splitCriticalEdge(Pair.first, Pair.second, NewSucc); } else LLVM_DEBUG(dbgs() << " *** Not legal to break critical edge\n"); } @@ -1263,6 +1264,9 @@ MachineSinking::FindSuccToSinkTo(MachineInstr &MI, MachineBasicBlock *MBB, if (SuccToSinkTo && SuccToSinkTo->isInlineAsmBrIndirectTarget()) return nullptr; + if (SuccToSinkTo && !TII->isSafeToSink(MI, SuccToSinkTo, CI)) + return nullptr; + return SuccToSinkTo; } |