[BPI] Add multiplication by scalar operators to BranchProbability

This patch just adds two operators to BranchProbability class:
(BP * scalar) and (BP *= scalar).

Reviewers: junbuml, chandlerc, sanjoy, vsk

Reviewed By: chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32334

llvm-svn: 300945

1 files changed, 48 insertions, 0 deletions

diff --git a/llvm/unittests/Support/BranchProbabilityTest.cpp b/llvm/unittests/Support/BranchProbabilityTest.cpp
index f03b09b66e8..54948baea51 100644
--- a/llvm/unittests/Support/BranchProbabilityTest.cpp
+++ b/llvm/unittests/Support/BranchProbabilityTest.cpp
@@ -115,6 +115,54 @@ TEST(BranchProbabilityTest, MoreOperators) {
   EXPECT_FALSE(BigZero >= BigOne);
 }
 
+TEST(BranchProbabilityTest, ArithmeticOperators) {
+  BP Z(0, 1);
+  BP O(1, 1);
+  BP H(1, 2);
+  BP Q(1, 4);
+  BP Q3(3, 4);
+
+  EXPECT_EQ(Z + O, O);
+  EXPECT_EQ(H + Z, H);
+  EXPECT_EQ(H + H, O);
+  EXPECT_EQ(Q + H, Q3);
+  EXPECT_EQ(Q + Q3, O);
+  EXPECT_EQ(H + Q3, O);
+  EXPECT_EQ(Q3 + Q3, O);
+
+  EXPECT_EQ(Z - O, Z);
+  EXPECT_EQ(O - Z, O);
+  EXPECT_EQ(O - H, H);
+  EXPECT_EQ(O - Q, Q3);
+  EXPECT_EQ(Q3 - H, Q);
+  EXPECT_EQ(Q - H, Z);
+  EXPECT_EQ(Q - Q3, Z);
+
+  EXPECT_EQ(Z * O, Z);
+  EXPECT_EQ(H * H, Q);
+  EXPECT_EQ(Q * O, Q);
+  EXPECT_EQ(O * O, O);
+  EXPECT_EQ(Z * Z, Z);
+
+  EXPECT_EQ(Z * 3, Z);
+  EXPECT_EQ(Q * 3, Q3);
+  EXPECT_EQ(H * 3, O);
+  EXPECT_EQ(Q3 * 2, O);
+  EXPECT_EQ(O * UINT32_MAX, O);
+
+  EXPECT_EQ(Z / 4, Z);
+  EXPECT_EQ(O / 4, Q);
+  EXPECT_EQ(Q3 / 3, Q);
+  EXPECT_EQ(H / 2, Q);
+  EXPECT_EQ(O / 2, H);
+  EXPECT_EQ(H / UINT32_MAX, Z);
+
+  BP Min(1, 1u << 31);
+
+  EXPECT_EQ(O / UINT32_MAX, Z);
+  EXPECT_EQ(Min * UINT32_MAX, O);
+}
+
 TEST(BranchProbabilityTest, getCompl) {
   EXPECT_EQ(BP(5, 7), BP(2, 7).getCompl());
   EXPECT_EQ(BP(2, 7), BP(5, 7).getCompl());