1 files changed, 53 insertions, 0 deletions
diff --git a/lib/Target/ARM/Thumb2HazardRecognizer.cpp b/lib/Target/ARM/Thumb2HazardRecognizer.cpp
new file mode 100644
index 0000000..172908d
--- /dev/null
+++ b/lib/Target/ARM/Thumb2HazardRecognizer.cpp
@@ -0,0 +1,53 @@
+//===-- Thumb2HazardRecognizer.cpp - Thumb2 postra hazard recognizer ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARM.h"
+#include "Thumb2HazardRecognizer.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/ScheduleDAG.h"
+using namespace llvm;
+
+ScheduleHazardRecognizer::HazardType
+Thumb2HazardRecognizer::getHazardType(SUnit *SU) {
+  if (ITBlockSize) {
+    MachineInstr *MI = SU->getInstr();
+    if (!MI->isDebugValue() && MI != ITBlockMIs[ITBlockSize-1])
+      return Hazard;
+  }
+
+  return PostRAHazardRecognizer::getHazardType(SU);
+}
+
+void Thumb2HazardRecognizer::Reset() {
+  ITBlockSize = 0;
+  PostRAHazardRecognizer::Reset();
+}
+
+void Thumb2HazardRecognizer::EmitInstruction(SUnit *SU) {
+  MachineInstr *MI = SU->getInstr();
+  unsigned Opcode = MI->getOpcode();
+  if (ITBlockSize) {
+    --ITBlockSize;
+  } else if (Opcode == ARM::t2IT) {
+    unsigned Mask = MI->getOperand(1).getImm();
+    unsigned NumTZ = CountTrailingZeros_32(Mask);
+    assert(NumTZ <= 3 && "Invalid IT mask!");
+    ITBlockSize = 4 - NumTZ;
+    MachineBasicBlock::iterator I = MI;
+    for (unsigned i = 0; i < ITBlockSize; ++i) {
+      // Advance to the next instruction, skipping any dbg_value instructions.
+      do {
+        ++I;
+      } while (I->isDebugValue());
+      ITBlockMIs[ITBlockSize-1-i] = &*I;
+    }
+  }
+
+  PostRAHazardRecognizer::EmitInstruction(SU);
+}