1 files changed, 96 insertions, 0 deletions
diff --git a/llvm/lib/Target/R600/SIFixControlFlowLiveIntervals.cpp b/llvm/lib/Target/R600/SIFixControlFlowLiveIntervals.cpp
new file mode 100644
index 000000000000..5fe8d19426dd
--- /dev/null
+++ b/llvm/lib/Target/R600/SIFixControlFlowLiveIntervals.cpp
@@ -0,0 +1,96 @@
+//===-- SIFixControlFlowLiveIntervals.cpp - Fix CF live intervals ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// \brief Spilling of EXEC masks used for control flow messes up control flow
+/// lowering, so mark all live intervals associated with CF instructions as
+/// non-spillable.
+///
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "SIInstrInfo.h"
+#include "SIRegisterInfo.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachinePostDominators.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "si-fix-cf-live-intervals"
+
+namespace {
+
+class SIFixControlFlowLiveIntervals : public MachineFunctionPass {
+public:
+  static char ID;
+
+public:
+  SIFixControlFlowLiveIntervals() : MachineFunctionPass(ID) {
+    initializeSIFixControlFlowLiveIntervalsPass(*PassRegistry::getPassRegistry());
+  }
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+  const char *getPassName() const override {
+    return "SI Fix CF Live Intervals";
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<LiveIntervals>();
+    AU.setPreservesAll();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+};
+
+} // End anonymous namespace.
+
+INITIALIZE_PASS_BEGIN(SIFixControlFlowLiveIntervals, DEBUG_TYPE,
+                      "SI Fix CF Live Intervals", false, false)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
+INITIALIZE_PASS_END(SIFixControlFlowLiveIntervals, DEBUG_TYPE,
+                    "SI Fix CF Live Intervals", false, false)
+
+char SIFixControlFlowLiveIntervals::ID = 0;
+
+char &llvm::SIFixControlFlowLiveIntervalsID = SIFixControlFlowLiveIntervals::ID;
+
+FunctionPass *llvm::createSIFixControlFlowLiveIntervalsPass() {
+  return new SIFixControlFlowLiveIntervals();
+}
+
+bool SIFixControlFlowLiveIntervals::runOnMachineFunction(MachineFunction &MF) {
+  LiveIntervals *LIS = &getAnalysis<LiveIntervals>();
+
+  for (const MachineBasicBlock &MBB : MF) {
+    for (const MachineInstr &MI : MBB) {
+      switch (MI.getOpcode()) {
+        case AMDGPU::SI_IF:
+        case AMDGPU::SI_ELSE:
+        case AMDGPU::SI_BREAK:
+        case AMDGPU::SI_IF_BREAK:
+        case AMDGPU::SI_ELSE_BREAK:
+        case AMDGPU::SI_END_CF: {
+          unsigned Reg = MI.getOperand(0).getReg();
+          LIS->getInterval(Reg).markNotSpillable();
+          break;
+        }
+        default:
+          break;
+      }
+    }
+  }
+
+  return false;
+}