AMDGPU/SI: Fix listing of Low and High latency instructions

[axeldavy]

Summary

A few instruction types were missing.

[arsenm]

It's still missing a few. VINTRP and EXP. I think it would be better to check instruction latency data. In absence of that, I think it would be simpler to just use isHighLatencyInstruction, and !isHighLatencyInstruction

[axeldavy]

In D30148#682960, @arsenm wrote:

It's still missing a few. VINTRP and EXP. I think it would be better to check instruction latency data. In absence of that, I think it would be simpler to just use isHighLatencyInstruction, and !isHighLatencyInstruction

The true usage of these helper functions is to deduce instructions which need a VMCNT wait or a LGKMCNT wait (former ones being incorrectly called 'high latency' and the latter ones 'lon latency').

What about renaming to isVMCNTInstruction and isLGKMCNTInstruction ?

[vpykhtin]

In D30148#686726, @axeldavy wrote:

In D30148#682960, @arsenm wrote:

It's still missing a few. VINTRP and EXP. I think it would be better to check instruction latency data. In absence of that, I think it would be simpler to just use isHighLatencyInstruction, and !isHighLatencyInstruction

The true usage of these helper functions is to deduce instructions which need a VMCNT wait or a LGKMCNT wait (former ones being incorrectly called 'high latency' and the latter ones 'lon latency').

What about renaming to isVMCNTInstruction and isLGKMCNTInstruction ?

SIInstrInfo has helper function:

static bool usesVM_CNT(const MachineInstr &MI)

It doesn't however contains the analogue for LGKM though it can be easily added.

[axeldavy]

usesVM_CNT and usesLGKM_CNT is probably the best way forward (and dropping is*LatencyInstruction)

lib/Target/AMDGPU/SIInstrInfo.cpp

 bool SIInstrInfo::isLowLatencyInstruction(const MachineInstr &MI) const {
   unsigned Opc = MI.getOpcode();
 
-  return isSMRD(Opc);
+  return isSMRD(Opc) || isDS(Opc);
 }
 
 bool SIInstrInfo::isHighLatencyInstruction(const MachineInstr &MI) const {
   unsigned Opc = MI.getOpcode();
 
-  return isMUBUF(Opc) || isMTBUF(Opc) || isMIMG(Opc);
+  return isMUBUF(Opc) || isMTBUF(Opc) || isMIMG(Opc) || isFLAT(Opc);
 }
 
 unsigned SIInstrInfo::isStackAccess(const MachineInstr &MI,