Branch profiling: floating-point avoidance.

Patch by: Jakub Staszak!

Introduces BranchProbability. Changes unsigned to uint32_t all over and
uint64_t only when overflow is expected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132867 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 50 insertions, 0 deletions

diff --git a/include/llvm/Support/BranchProbability.h b/include/llvm/Support/BranchProbability.h
new file mode 100644
index 0000000000..7ba649133b
--- /dev/null
+++ b/include/llvm/Support/BranchProbability.h
@@ -0,0 +1,50 @@
+//===- BranchProbability.h - Branch Probability Analysis --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Definition of BranchProbability shared by IR and Machine Instructions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_BRANCHPROBABILITY_H
+#define LLVM_SUPPORT_BRANCHPROBABILITY_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+class raw_ostream;
+class BranchProbabilityInfo;
+class MachineBranchProbabilityInfo;
+class MachineBasicBlock;
+
+// This class represents Branch Probability as a non-negative fraction.
+class BranchProbability {
+  friend class BranchProbabilityInfo;
+  friend class MachineBranchProbabilityInfo;
+  friend class MachineBasicBlock;
+
+  // Numerator
+  uint32_t N;
+
+  // Denominator
+  uint32_t D;
+
+  BranchProbability(uint32_t n, uint32_t d);
+
+public:
+  raw_ostream &print(raw_ostream &OS) const;
+
+  void dump() const;
+};
+
+raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob);
+
+}
+
+#endif