Revert "AMDGPU: Handle folding frame indexes into s_add_i32 (llvm#101694)"

This reverts commit 8039886.

breaks hip_on_rocclr build

Change-Id: I37907f36632c22cecbd1d12efe9758e4f23b7ebf

Author: ronlieb

llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp

@@ -2612,299 +2612,6 @@ bool SIRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
       MI->eraseFromParent();
       return true;
     }
-    case AMDGPU::V_ADD_U32_e32:
-    case AMDGPU::V_ADD_U32_e64:
-    case AMDGPU::V_ADD_CO_U32_e32:
-    case AMDGPU::V_ADD_CO_U32_e64: {
-      // TODO: Handle sub, and, or.
-      unsigned NumDefs = MI->getNumExplicitDefs();
-      unsigned Src0Idx = NumDefs;
-
-      bool HasClamp = false;
-      MachineOperand *VCCOp = nullptr;
-
-      switch (MI->getOpcode()) {
-      case AMDGPU::V_ADD_U32_e32:
-        break;
-      case AMDGPU::V_ADD_U32_e64:
-        HasClamp = MI->getOperand(3).getImm();
-        break;
-      case AMDGPU::V_ADD_CO_U32_e32:
-        VCCOp = &MI->getOperand(3);
-        break;
-      case AMDGPU::V_ADD_CO_U32_e64:
-        VCCOp = &MI->getOperand(1);
-        HasClamp = MI->getOperand(4).getImm();
-        break;
-      default:
-        break;
-      }
-      bool DeadVCC = !VCCOp || VCCOp->isDead();
-      MachineOperand &DstOp = MI->getOperand(0);
-      Register DstReg = DstOp.getReg();
-
-      unsigned OtherOpIdx =
-          FIOperandNum == Src0Idx ? FIOperandNum + 1 : Src0Idx;
-      MachineOperand *OtherOp = &MI->getOperand(OtherOpIdx);
-
-      unsigned Src1Idx = Src0Idx + 1;
-      Register MaterializedReg = FrameReg;
-      Register ScavengedVGPR;
-
-      if (FrameReg && !ST.enableFlatScratch()) {
-        // We should just do an in-place update of the result register. However,
-        // the value there may also be used by the add, in which case we need a
-        // temporary register.
-        //
-        // FIXME: The scavenger is not finding the result register in the
-        // common case where the add does not read the register.
-
-        ScavengedVGPR = RS->scavengeRegisterBackwards(
-            AMDGPU::VGPR_32RegClass, MI, /*RestoreAfter=*/false, /*SPAdj=*/0);
-
-        // TODO: If we have a free SGPR, it's sometimes better to use a scalar
-        // shift.
-        BuildMI(*MBB, *MI, DL, TII->get(AMDGPU::V_LSHRREV_B32_e64))
-            .addDef(ScavengedVGPR, RegState::Renamable)
-            .addImm(ST.getWavefrontSizeLog2())
-            .addReg(FrameReg);
-        MaterializedReg = ScavengedVGPR;
-      }
-
-      int64_t Offset = FrameInfo.getObjectOffset(Index);
-      // For the non-immediate case, we could fall through to the default
-      // handling, but we do an in-place update of the result register here to
-      // avoid scavenging another register.
-      if (OtherOp->isImm()) {
-        OtherOp->setImm(OtherOp->getImm() + Offset);
-        Offset = 0;
-      }
-
-      if ((!OtherOp->isImm() || OtherOp->getImm() != 0) && MaterializedReg) {
-        if (ST.enableFlatScratch() &&
-            !TII->isOperandLegal(*MI, Src1Idx, OtherOp)) {
-          // We didn't need the shift above, so we have an SGPR for the frame
-          // register, but may have a VGPR only operand.
-          //
-          // TODO: On gfx10+, we can easily change the opcode to the e64 version
-          // and use the higher constant bus restriction to avoid this copy.
-
-          if (!ScavengedVGPR) {
-            ScavengedVGPR = RS->scavengeRegisterBackwards(
-                AMDGPU::VGPR_32RegClass, MI, /*RestoreAfter=*/false,
-                /*SPAdj=*/0);
-          }
-
-          assert(ScavengedVGPR != DstReg);
-
-          BuildMI(*MBB, *MI, DL, TII->get(AMDGPU::V_MOV_B32_e32), ScavengedVGPR)
-              .addReg(MaterializedReg,
-                      MaterializedReg != FrameReg ? RegState::Kill : 0);
-          MaterializedReg = ScavengedVGPR;
-        }
-
-        // TODO: In the flat scratch case, if this is an add of an SGPR, and SCC
-        // is not live, we could use a scalar add + vector add instead of 2
-        // vector adds.
-        auto AddI32 = BuildMI(*MBB, *MI, DL, TII->get(MI->getOpcode()))
-                          .addDef(DstReg, RegState::Renamable);
-        if (NumDefs == 2)
-          AddI32.add(MI->getOperand(1));
-
-        unsigned MaterializedRegFlags =
-            MaterializedReg != FrameReg ? RegState::Kill : 0;
-
-        if (isVGPRClass(getPhysRegBaseClass(MaterializedReg))) {
-          // If we know we have a VGPR already, it's more likely the other
-          // operand is a legal vsrc0.
-          AddI32
-            .add(*OtherOp)
-            .addReg(MaterializedReg, MaterializedRegFlags);
-        } else {
-          // Commute operands to avoid violating VOP2 restrictions. This will
-          // typically happen when using scratch.
-          AddI32
-            .addReg(MaterializedReg, MaterializedRegFlags)
-            .add(*OtherOp);
-        }
-
-        if (MI->getOpcode() == AMDGPU::V_ADD_CO_U32_e64 ||
-            MI->getOpcode() == AMDGPU::V_ADD_U32_e64)
-          AddI32.addImm(0); // clamp
-
-        if (MI->getOpcode() == AMDGPU::V_ADD_CO_U32_e32)
-          AddI32.setOperandDead(3); // Dead vcc
-
-        MaterializedReg = DstReg;
-
-        OtherOp->ChangeToRegister(MaterializedReg, false);
-        OtherOp->setIsKill(true);
-        FIOp->ChangeToImmediate(Offset);
-        Offset = 0;
-      } else if (Offset != 0) {
-        assert(!MaterializedReg);
-        FIOp->ChangeToImmediate(Offset);
-        Offset = 0;
-      } else {
-        if (DeadVCC && !HasClamp) {
-          assert(Offset == 0);
-
-          // TODO: Losing kills and implicit operands. Just mutate to copy and
-          // let lowerCopy deal with it?
-          if (OtherOp->isReg() && OtherOp->getReg() == DstReg) {
-            // Folded to an identity copy.
-            MI->eraseFromParent();
-            return true;
-          }
-
-          // The immediate value should be in OtherOp
-          MI->setDesc(TII->get(AMDGPU::V_MOV_B32_e32));
-          MI->removeOperand(FIOperandNum);
-
-          unsigned NumOps = MI->getNumOperands();
-          for (unsigned I = NumOps - 2; I >= 2; --I)
-            MI->removeOperand(I);
-
-          if (NumDefs == 2)
-            MI->removeOperand(1);
-
-          // The code below can't deal with a mov.
-          return true;
-        }
-
-        // This folded to a constant, but we have to keep the add around for
-        // pointless implicit defs or clamp modifier.
-        FIOp->ChangeToImmediate(0);
-      }
-
-      // Try to improve legality by commuting.
-      if (!TII->isOperandLegal(*MI, Src1Idx) && TII->commuteInstruction(*MI)) {
-        std::swap(FIOp, OtherOp);
-        std::swap(FIOperandNum, OtherOpIdx);
-      }
-
-      for (unsigned SrcIdx : {Src1Idx, Src0Idx}) {
-        // Depending on operand constraints we may need to insert another copy.
-        if (!TII->isOperandLegal(*MI, SrcIdx)) {
-          // If commuting didn't make the operands legal, we need to materialize
-          // in a register.
-          // TODO: Can use SGPR on gfx10+ in some cases.
-          if (!ScavengedVGPR) {
-            ScavengedVGPR = RS->scavengeRegisterBackwards(
-                AMDGPU::VGPR_32RegClass, MI, /*RestoreAfter=*/false,
-                /*SPAdj=*/0);
-          }
-
-          assert(ScavengedVGPR != DstReg);
-
-          MachineOperand &Src = MI->getOperand(SrcIdx);
-          BuildMI(*MBB, *MI, DL, TII->get(AMDGPU::V_MOV_B32_e32), ScavengedVGPR)
-              .add(Src);
-
-          Src.ChangeToRegister(ScavengedVGPR, false);
-          Src.setIsKill(true);
-        }
-      }
-
-      // Fold out add of 0 case that can appear in kernels.
-      if (FIOp->isImm() && FIOp->getImm() == 0 && DeadVCC && !HasClamp) {
-        if (OtherOp->isReg() && OtherOp->getReg() != DstReg) {
-          BuildMI(*MBB, *MI, DL, TII->get(AMDGPU::COPY), DstReg).add(*OtherOp);
-        }
-
-        MI->eraseFromParent();
-      }
-
-      return true;
-    }
-    case AMDGPU::S_ADD_I32: {
-      // TODO: Handle s_or_b32, s_and_b32.
-      unsigned OtherOpIdx = FIOperandNum == 1 ? 2 : 1;
-      MachineOperand &OtherOp = MI->getOperand(OtherOpIdx);
-
-      assert(FrameReg || MFI->isBottomOfStack());
-
-      MachineOperand &DstOp = MI->getOperand(0);
-      const DebugLoc &DL = MI->getDebugLoc();
-      Register MaterializedReg = FrameReg;
-
-      // Defend against live scc, which should never happen in practice.
-      bool DeadSCC = MI->getOperand(3).isDead();
-
-      Register TmpReg;
-
-      if (FrameReg && !ST.enableFlatScratch()) {
-        // FIXME: In the common case where the add does not also read its result
-        // (i.e. this isn't a reg += fi), it's not finding the dest reg as
-        // available.
-        TmpReg = RS->scavengeRegisterBackwards(AMDGPU::SReg_32_XM0RegClass, MI,
-                                               false, 0);
-        BuildMI(*MBB, *MI, DL, TII->get(AMDGPU::S_LSHR_B32))
-            .addDef(TmpReg, RegState::Renamable)
-            .addReg(FrameReg)
-            .addImm(ST.getWavefrontSizeLog2())
-            .setOperandDead(3); // Set SCC dead
-        MaterializedReg = TmpReg;
-      }
-
-      int64_t Offset = FrameInfo.getObjectOffset(Index);
-
-      // For the non-immediate case, we could fall through to the default
-      // handling, but we do an in-place update of the result register here to
-      // avoid scavenging another register.
-      if (OtherOp.isImm()) {
-        OtherOp.setImm(OtherOp.getImm() + Offset);
-        Offset = 0;
-
-        if (MaterializedReg)
-          FIOp->ChangeToRegister(MaterializedReg, false);
-        else
-          FIOp->ChangeToImmediate(0);
-      } else if (MaterializedReg) {
-        // If we can't fold the other operand, do another increment.
-        Register DstReg = DstOp.getReg();
-
-        if (!TmpReg && MaterializedReg == FrameReg) {
-          TmpReg = RS->scavengeRegisterBackwards(AMDGPU::SReg_32_XM0RegClass,
-                                                 MI, false, 0);
-          DstReg = TmpReg;
-        }
-
-        auto AddI32 = BuildMI(*MBB, *MI, DL, TII->get(AMDGPU::S_ADD_I32))
-                          .addDef(DstReg, RegState::Renamable)
-                          .addReg(MaterializedReg, RegState::Kill)
-                          .add(OtherOp);
-        if (DeadSCC)
-          AddI32.setOperandDead(3);
-
-        MaterializedReg = DstReg;
-
-        OtherOp.ChangeToRegister(MaterializedReg, false);
-        OtherOp.setIsKill(true);
-        OtherOp.setIsRenamable(true);
-        FIOp->ChangeToImmediate(Offset);
-      } else {
-        // If we don't have any other offset to apply, we can just directly
-        // interpret the frame index as the offset.
-        FIOp->ChangeToImmediate(Offset);
-      }
-
-      if (DeadSCC && OtherOp.isImm() && OtherOp.getImm() == 0) {
-        assert(Offset == 0);
-        MI->removeOperand(3);
-        MI->removeOperand(OtherOpIdx);
-        MI->setDesc(TII->get(FIOp->isReg() ? AMDGPU::COPY : AMDGPU::S_MOV_B32));
-      } else if (DeadSCC && FIOp->isImm() && FIOp->getImm() == 0) {
-        assert(Offset == 0);
-        MI->removeOperand(3);
-        MI->removeOperand(FIOperandNum);
-        MI->setDesc(
-            TII->get(OtherOp.isReg() ? AMDGPU::COPY : AMDGPU::S_MOV_B32));
-      }
-
-      assert(!FIOp->isFI());
-      return true;
-    }
     default: {
       // Other access to frame index
       const DebugLoc &DL = MI->getDebugLoc();