From a51941f3140cf0ed5c79bf828ff3e418fc5df71d Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@gmail.com>
Date: Mon, 8 May 2017 04:55:09 +0000
Subject: [PATCH] [APInt] Add support for multiplying by a uint64_t.

This makes multiply similar to add, sub, xor, and, and or.

llvm-svn: 302402
---
 llvm/include/llvm/ADT/APInt.h    | 11 +++++++++++
 llvm/lib/Support/APInt.cpp       | 10 ++++++++++
 llvm/unittests/ADT/APIntTest.cpp | 19 +++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index 63c92c1..c3822e3 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -842,6 +842,7 @@ public:
   ///
   /// \returns *this
   APInt &operator*=(const APInt &RHS);
+  APInt &operator*=(uint64_t RHS);
 
   /// \brief Addition assignment operator.
   ///
@@ -2043,6 +2044,16 @@ inline APInt operator-(uint64_t LHS, APInt b) {
   return b;
 }
 
+inline APInt operator*(APInt a, uint64_t RHS) {
+  a *= RHS;
+  return a;
+}
+
+inline APInt operator*(uint64_t LHS, APInt b) {
+  b *= LHS;
+  return b;
+}
+
 
 namespace APIntOps {
 
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index ee5c9f9..e2cfb90 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -256,6 +256,16 @@ APInt& APInt::operator*=(const APInt& RHS) {
   return *this;
 }
 
+APInt& APInt::operator*=(uint64_t RHS) {
+  if (isSingleWord()) {
+    U.VAL *= RHS;
+  } else {
+    unsigned NumWords = getNumWords();
+    tcMultiplyPart(U.pVal, U.pVal, RHS, 0, NumWords, NumWords, false);
+  }
+  return clearUnusedBits();
+}
+
 bool APInt::EqualSlowCase(const APInt& RHS) const {
   return std::equal(U.pVal, U.pVal + getNumWords(), RHS.U.pVal);
 }
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index bb6cf35..5594955 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -2142,4 +2142,23 @@ TEST(APIntTest, sext) {
   EXPECT_EQ(63U, i32_neg1.countPopulation());
 }
 
+TEST(APIntTest, multiply) {
+  APInt i64(64, 1234);
+
+  EXPECT_EQ(7006652, i64 * 5678);
+  EXPECT_EQ(7006652, 5678 * i64);
+
+  APInt i128 = APInt::getOneBitSet(128, 64);
+  APInt i128_1234(128, 1234);
+  i128_1234 <<= 64;
+  EXPECT_EQ(i128_1234, i128 * 1234);
+  EXPECT_EQ(i128_1234, 1234 * i128);
+
+  APInt i96 = APInt::getOneBitSet(96, 64);
+  i96 *= ~0ULL;
+  EXPECT_EQ(32U, i96.countLeadingOnes());
+  EXPECT_EQ(32U, i96.countPopulation());
+  EXPECT_EQ(64U, i96.countTrailingZeros());
+}
+
 } // end anonymous namespace
-- 
2.7.4