1 files changed, 0 insertions, 159 deletions
diff --git a/llvm/lib/Target/AMDGPU/SIRemoveShortExecBranches.cpp b/llvm/lib/Target/AMDGPU/SIRemoveShortExecBranches.cpp
deleted file mode 100644
index d30ff4a3fd15..000000000000
--- a/llvm/lib/Target/AMDGPU/SIRemoveShortExecBranches.cpp
+++ /dev/null
@@ -1,159 +0,0 @@
-//===-- SIRemoveShortExecBranches.cpp ------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-/// \file
-/// This pass optmizes the s_cbranch_execz instructions.
-/// The pass removes this skip instruction for short branches,
-/// if there is no unwanted sideeffect in the fallthrough code sequence.
-///
-//===----------------------------------------------------------------------===//
-
-#include "AMDGPU.h"
-#include "GCNSubtarget.h"
-#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/Support/CommandLine.h"
-
-using namespace llvm;
-
-#define DEBUG_TYPE "si-remove-short-exec-branches"
-
-static unsigned SkipThreshold;
-
-static cl::opt<unsigned, true> SkipThresholdFlag(
-    "amdgpu-skip-threshold", cl::Hidden,
-    cl::desc(
-        "Number of instructions before jumping over divergent control flow"),
-    cl::location(SkipThreshold), cl::init(12));
-
-namespace {
-
-class SIRemoveShortExecBranches : public MachineFunctionPass {
-private:
-  const SIInstrInfo *TII = nullptr;
-  bool getBlockDestinations(MachineBasicBlock &SrcMBB,
-                            MachineBasicBlock *&TrueMBB,
-                            MachineBasicBlock *&FalseMBB,
-                            SmallVectorImpl<MachineOperand> &Cond);
-  bool mustRetainExeczBranch(const MachineBasicBlock &From,
-                             const MachineBasicBlock &To) const;
-  bool removeExeczBranch(MachineInstr &MI, MachineBasicBlock &SrcMBB);
-
-public:
-  static char ID;
-
-  SIRemoveShortExecBranches() : MachineFunctionPass(ID) {
-    initializeSIRemoveShortExecBranchesPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnMachineFunction(MachineFunction &MF) override;
-};
-
-} // End anonymous namespace.
-
-INITIALIZE_PASS(SIRemoveShortExecBranches, DEBUG_TYPE,
-                "SI remove short exec branches", false, false)
-
-char SIRemoveShortExecBranches::ID = 0;
-
-char &llvm::SIRemoveShortExecBranchesID = SIRemoveShortExecBranches::ID;
-
-bool SIRemoveShortExecBranches::getBlockDestinations(
-    MachineBasicBlock &SrcMBB, MachineBasicBlock *&TrueMBB,
-    MachineBasicBlock *&FalseMBB, SmallVectorImpl<MachineOperand> &Cond) {
-  if (TII->analyzeBranch(SrcMBB, TrueMBB, FalseMBB, Cond))
-    return false;
-
-  if (!FalseMBB)
-    FalseMBB = SrcMBB.getNextNode();
-
-  return true;
-}
-
-bool SIRemoveShortExecBranches::mustRetainExeczBranch(
-    const MachineBasicBlock &From, const MachineBasicBlock &To) const {
-  unsigned NumInstr = 0;
-  const MachineFunction *MF = From.getParent();
-
-  for (MachineFunction::const_iterator MBBI(&From), ToI(&To), End = MF->end();
-       MBBI != End && MBBI != ToI; ++MBBI) {
-    const MachineBasicBlock &MBB = *MBBI;
-
-    for (MachineBasicBlock::const_iterator I = MBB.begin(), E = MBB.end();
-         I != E; ++I) {
-      // When a uniform loop is inside non-uniform control flow, the branch
-      // leaving the loop might never be taken when EXEC = 0.
-      // Hence we should retain cbranch out of the loop lest it become infinite.
-      if (I->isConditionalBranch())
-        return true;
-
-      if (TII->hasUnwantedEffectsWhenEXECEmpty(*I))
-        return true;
-
-      if (TII->isKillTerminator(I->getOpcode()))
-        return true;
-
-      // These instructions are potentially expensive even if EXEC = 0.
-      if (TII->isSMRD(*I) || TII->isVMEM(*I) || TII->isFLAT(*I) ||
-          I->getOpcode() == AMDGPU::S_WAITCNT)
-        return true;
-
-      ++NumInstr;
-      if (NumInstr >= SkipThreshold)
-        return true;
-    }
-  }
-
-  return false;
-}
-
-// Returns true if the skip branch instruction is removed.
-bool SIRemoveShortExecBranches::removeExeczBranch(MachineInstr &MI,
-                                                  MachineBasicBlock &SrcMBB) {
-  MachineBasicBlock *TrueMBB = nullptr;
-  MachineBasicBlock *FalseMBB = nullptr;
-  SmallVector<MachineOperand, 1> Cond;
-
-  if (!getBlockDestinations(SrcMBB, TrueMBB, FalseMBB, Cond))
-    return false;
-
-  // Consider only the forward branches.
-  if ((SrcMBB.getNumber() >= TrueMBB->getNumber()) ||
-      mustRetainExeczBranch(*FalseMBB, *TrueMBB))
-    return false;
-
-  LLVM_DEBUG(dbgs() << "Removing the execz branch: " << MI);
-  MI.eraseFromParent();
-  SrcMBB.removeSuccessor(TrueMBB);
-
-  return true;
-}
-
-bool SIRemoveShortExecBranches::runOnMachineFunction(MachineFunction &MF) {
-  const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
-  TII = ST.getInstrInfo();
-  MF.RenumberBlocks();
-  bool Changed = false;
-
-  for (MachineBasicBlock &MBB : MF) {
-    MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
-    if (MBBI == MBB.end())
-      continue;
-
-    MachineInstr &MI = *MBBI;
-    switch (MI.getOpcode()) {
-    case AMDGPU::S_CBRANCH_EXECZ:
-      Changed = removeExeczBranch(MI, MBB);
-      break;
-    default:
-      break;
-    }
-  }
-
-  return Changed;
-}