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

2 files changed, 45 insertions, 0 deletions

diff --git a/lib/Support/BranchProbability.cpp b/lib/Support/BranchProbability.cpp
new file mode 100644
index 0000000..97342da
--- /dev/null
+++ b/lib/Support/BranchProbability.cpp
@@ -0,0 +1,44 @@
+//===-------------- lib/Support/BranchProbability.cpp -----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements Branch Probability class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/BranchProbability.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+BranchProbability::BranchProbability(uint32_t n, uint32_t d) {
+  assert(d > 0 && "Denomiator cannot be 0!");
+  assert(n <= d && "Probability cannot be bigger than 1!");
+  N = n;
+  D = d;
+}
+
+raw_ostream &BranchProbability::print(raw_ostream &OS) const {
+  OS << N << " / " << D << " = " << ((double)N / D);
+  return OS;
+}
+
+void BranchProbability::dump() const {
+  print(dbgs());
+  dbgs() << "\n";
+}
+
+namespace llvm {
+
+raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob) {
+  Prob.print(OS);
+  return OS;
+}
+
+}
diff --git a/lib/Support/CMakeLists.txt b/lib/Support/CMakeLists.txt
index a0e997d..867d930 100644
--- a/lib/Support/CMakeLists.txt
+++ b/lib/Support/CMakeLists.txt
@@ -9,6 +9,7 @@ add_llvm_library(LLVMSupport
   APInt.cpp
   APSInt.cpp
   Allocator.cpp
+  BranchProbability.cpp
   circular_raw_ostream.cpp
   CommandLine.cpp
   ConstantRange.cpp