From 156f9e8a04e21fca4c50d8388723b7eb75a44b3c Mon Sep 17 00:00:00 2001
From: Diego Novillo <dnovillo@google.com>
Date: Thu, 30 Apr 2015 13:22:48 +0000
Subject: [PATCH] Fix private constructor for ScaledNumber.

Summary:
The private constructor for ScaledNumber was using uint64_t instead of
DigitsT. This was preventing instantiations of ScaledNumber with
anything other than uint64_t types.

In implementing the tests, I ran into another issue. Operators >>= and
<<= did not have variants for accepting other ScaledNumber as the shift
argument. This is expected by the SCALED_NUMBER_BOP.

It makes no sense to allow shifting a ScaledNumber by another
ScaledNumber, so the patch includes two new templates for shifting
ScaledNumbers.

Reviewers: dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9350

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236232 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/ScaledNumber.h    | 16 +++++++++++++---
 unittests/Support/ScaledNumberTest.cpp | 24 ++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/include/llvm/Support/ScaledNumber.h b/include/llvm/Support/ScaledNumber.h
index a1c4c80c356..dbe88f2e96f 100644
--- a/include/llvm/Support/ScaledNumber.h
+++ b/include/llvm/Support/ScaledNumber.h
@@ -514,7 +514,7 @@ public:
       : Digits(Digits), Scale(Scale) {}
 
 private:
-  ScaledNumber(const std::pair<uint64_t, int16_t> &X)
+  ScaledNumber(const std::pair<DigitsT, int16_t> &X)
       : Digits(X.first), Scale(X.second) {}
 
 public:
@@ -732,10 +732,20 @@ SCALED_NUMBER_BOP(+, += )
 SCALED_NUMBER_BOP(-, -= )
 SCALED_NUMBER_BOP(*, *= )
 SCALED_NUMBER_BOP(/, /= )
-SCALED_NUMBER_BOP(<<, <<= )
-SCALED_NUMBER_BOP(>>, >>= )
 #undef SCALED_NUMBER_BOP
 
+template <class DigitsT>
+ScaledNumber<DigitsT> operator<<(const ScaledNumber<DigitsT> &L,
+                                 int16_t Shift) {
+  return ScaledNumber<DigitsT>(L) <<= Shift;
+}
+
+template <class DigitsT>
+ScaledNumber<DigitsT> operator>>(const ScaledNumber<DigitsT> &L,
+                                 int16_t Shift) {
+  return ScaledNumber<DigitsT>(L) >>= Shift;
+}
+
 template <class DigitsT>
 raw_ostream &operator<<(raw_ostream &OS, const ScaledNumber<DigitsT> &X) {
   return X.print(OS, 10);
diff --git a/unittests/Support/ScaledNumberTest.cpp b/unittests/Support/ScaledNumberTest.cpp
index 216292cc265..38721552ec9 100644
--- a/unittests/Support/ScaledNumberTest.cpp
+++ b/unittests/Support/ScaledNumberTest.cpp
@@ -532,4 +532,28 @@ TEST(ScaledNumberHelpersTest, getDifference) {
   EXPECT_EQ(SP64(0, 0), getDifference64(1, -64, 1, -1));
 }
 
+TEST(ScaledNumberHelpersTest, arithmeticOperators) {
+  EXPECT_EQ(ScaledNumber<uint32_t>(10, 0),
+            ScaledNumber<uint32_t>(1, 3) + ScaledNumber<uint32_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint32_t>(6, 0),
+            ScaledNumber<uint32_t>(1, 3) - ScaledNumber<uint32_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint32_t>(2, 3),
+            ScaledNumber<uint32_t>(1, 3) * ScaledNumber<uint32_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint32_t>(1, 2),
+            ScaledNumber<uint32_t>(1, 3) / ScaledNumber<uint32_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint32_t>(1, 2), ScaledNumber<uint32_t>(1, 3) >> 1);
+  EXPECT_EQ(ScaledNumber<uint32_t>(1, 4), ScaledNumber<uint32_t>(1, 3) << 1);
+
+  EXPECT_EQ(ScaledNumber<uint64_t>(10, 0),
+            ScaledNumber<uint64_t>(1, 3) + ScaledNumber<uint64_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint64_t>(6, 0),
+            ScaledNumber<uint64_t>(1, 3) - ScaledNumber<uint64_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint64_t>(2, 3),
+            ScaledNumber<uint64_t>(1, 3) * ScaledNumber<uint64_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint64_t>(1, 2),
+            ScaledNumber<uint64_t>(1, 3) / ScaledNumber<uint64_t>(1, 1));
+  EXPECT_EQ(ScaledNumber<uint64_t>(1, 2), ScaledNumber<uint64_t>(1, 3) >> 1);
+  EXPECT_EQ(ScaledNumber<uint64_t>(1, 4), ScaledNumber<uint64_t>(1, 3) << 1);
+}
+
 } // end namespace