[AMDGPU] Remove ShouldPreferAnother after switch to postmisched

[rampitec]

I think we decided to keep this as long as we technically support old post-RA scheduler.

llvm/lib/Target/AMDGPU/GCNHazardRecognizer.h

public:
   void EmitInstruction(SUnit *SU) override;
   void EmitInstruction(MachineInstr *MI) override;
   HazardType getHazardType(SUnit *SU, int Stalls) override;
   void EmitNoop() override;
   unsigned PreEmitNoops(MachineInstr *) override;
   unsigned PreEmitNoopsCommon(MachineInstr *);
   void AdvanceCycle() override;
   void RecedeCycle() override;
-  bool ShouldPreferAnother(SUnit *SU) override;
   void Reset() override;
 };
 
 } // end namespace llvm
 
 #endif //LLVM_LIB_TARGET_AMDGPUHAZARDRECOGNIZERS_H

llvm/lib/Target/AMDGPU/GCNHazardRecognizer.cpp

default: NeedWaitStates = SMFMA32x32ReadVgprVALUWarWaitStates;
              break;
     }
 
     int WaitStatesNeededForUse = NeedWaitStates - WaitStatesSinceUse;
     WaitStatesNeeded = std::max(WaitStatesNeeded, WaitStatesNeededForUse);
   }
 
   return WaitStatesNeeded;
-}
-
-bool GCNHazardRecognizer::ShouldPreferAnother(SUnit *SU) {
-  if (!SU->isInstr())
-    return false;
-
-  const MachineInstr *MAI = nullptr;
-  auto IsMFMAFn = [&MAI](const MachineInstr &MI) {
-    MAI = nullptr;
-    if (SIInstrInfo::isMAI(MI) &&
-        MI.getOpcode() != AMDGPU::V_ACCVGPR_WRITE_B32_e64 &&
-        MI.getOpcode() != AMDGPU::V_ACCVGPR_READ_B32_e64)
-      MAI = &MI;
-    return MAI != nullptr;
-  };
-
-  MachineInstr *MI = SU->getInstr();
-  if (IsMFMAFn(*MI)) {
-    int W = getWaitStatesSince(IsMFMAFn, 16);
-    if (MAI)
-      return W < (int)TSchedModel.computeInstrLatency(MAI);
-  }
-
-  return false;
-}
+}

llvm/test/CodeGen/AMDGPU/sched-prefer-non-mfma.mir

-# RUN: llc -march=amdgcn -mcpu=gfx908 -run-pass post-RA-sched -amdgpu-disable-power-sched -verify-machineinstrs -o - %s | FileCheck -check-prefix=GCN %s
-
-# GCN-LABEL: name: unrelated_mfma
-# GCN: V_MFMA_F32_32X32X1F32
-# GCN: S_CMP_LG_U32
-# GCN: V_MFMA_F32_32X32X1F32
-
----
-name:            unrelated_mfma
-body:             |
-  bb.0.entry:
-    renamable $agpr0_agpr1_agpr2_agpr3_agpr4_agpr5_agpr6_agpr7_agpr8_agpr9_agpr10_agpr11_agpr12_agpr13_agpr14_agpr15_agpr16_agpr17_agpr18_agpr19_agpr20_agpr21_agpr22_agpr23_agpr24_agpr25_agpr26_agpr27_agpr28_agpr29_agpr30_agpr31 = V_MFMA_F32_32X32X1F32_e64 $vgpr67, $vgpr66, $agpr0_agpr1_agpr2_agpr3_agpr4_agpr5_agpr6_agpr7_agpr8_agpr9_agpr10_agpr11_agpr12_agpr13_agpr14_agpr15_agpr16_agpr17_agpr18_agpr19_agpr20_agpr21_agpr22_agpr23_agpr24_agpr25_agpr26_agpr27_agpr28_agpr29_agpr30_agpr31, 0, 0, 0, implicit $mode, implicit $exec
-    renamable $agpr32_agpr33_agpr34_agpr35_agpr36_agpr37_agpr38_agpr39_agpr40_agpr41_agpr42_agpr43_agpr44_agpr45_agpr46_agpr47_agpr48_agpr49_agpr50_agpr51_agpr52_agpr53_agpr54_agpr55_agpr56_agpr57_agpr58_agpr59_agpr60_agpr61_agpr62_agpr63 = V_MFMA_F32_32X32X1F32_e64 $vgpr69, $vgpr68, killed $agpr32_agpr33_agpr34_agpr35_agpr36_agpr37_agpr38_agpr39_agpr40_agpr41_agpr42_agpr43_agpr44_agpr45_agpr46_agpr47_agpr48_agpr49_agpr50_agpr51_agpr52_agpr53_agpr54_agpr55_agpr56_agpr57_agpr58_agpr59_agpr60_agpr61_agpr62_agpr63, 0, 0, 0, implicit $mode, implicit $exec
-    renamable $sgpr2 = S_ADD_U32 renamable $sgpr2, 4, implicit-def $scc
-    renamable $sgpr3 = S_ADDC_U32 renamable $sgpr3, 0, implicit-def dead $scc, implicit killed $scc
-    S_CMP_LG_U32 renamable $sgpr2, 64, implicit-def $scc
-
-...