From c67fe57e1e2e2d23a152fc4d16c916e2d388d9d2 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@gmail.com>
Date: Wed, 19 Apr 2017 17:01:58 +0000
Subject: [PATCH] [APInt] Move the 'return *this' from the slow cases of
 assignment operators inline. We should let the compiler see that the
 fast/slow cases both return *this.

I don't think we chain assignments together very often so this shouldn't matter much.

llvm-svn: 300715
---
 llvm/include/llvm/ADT/APInt.h | 35 ++++++++++++++++++-----------------
 llvm/lib/Support/APInt.cpp    | 17 +++++++----------
 2 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index 59b3ba0..3f93e68 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -195,7 +195,7 @@ private:
   void lshrSlowCase(unsigned ShiftAmt);
 
   /// out-of-line slow case for operator=
-  APInt &AssignSlowCase(const APInt &RHS);
+  void AssignSlowCase(const APInt &RHS);
 
   /// out-of-line slow case for operator==
   bool EqualSlowCase(const APInt &RHS) const LLVM_READONLY;
@@ -219,13 +219,13 @@ private:
   void flipAllBitsSlowCase();
 
   /// out-of-line slow case for operator&=.
-  APInt& AndAssignSlowCase(const APInt& RHS);
+  void AndAssignSlowCase(const APInt& RHS);
 
   /// out-of-line slow case for operator|=.
-  APInt& OrAssignSlowCase(const APInt& RHS);
+  void OrAssignSlowCase(const APInt& RHS);
 
   /// out-of-line slow case for operator^=.
-  APInt& XorAssignSlowCase(const APInt& RHS);
+  void XorAssignSlowCase(const APInt& RHS);
 
 public:
   /// \name Constructors
@@ -691,7 +691,8 @@ public:
       return clearUnusedBits();
     }
 
-    return AssignSlowCase(RHS);
+    AssignSlowCase(RHS);
+    return *this;
   }
 
   /// @brief Move assignment operator.
@@ -736,11 +737,11 @@ public:
   /// \returns *this after ANDing with RHS.
   APInt &operator&=(const APInt &RHS) {
     assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
-    if (isSingleWord()) {
+    if (isSingleWord())
       VAL &= RHS.VAL;
-      return *this;
-    }
-    return AndAssignSlowCase(RHS);
+    else
+      AndAssignSlowCase(RHS);
+    return *this;
   }
 
   /// \brief Bitwise AND assignment operator.
@@ -766,11 +767,11 @@ public:
   /// \returns *this after ORing with RHS.
   APInt &operator|=(const APInt &RHS) {
     assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
-    if (isSingleWord()) {
+    if (isSingleWord())
       VAL |= RHS.VAL;
-      return *this;
-    }
-    return OrAssignSlowCase(RHS);
+    else
+      OrAssignSlowCase(RHS);
+    return *this;
   }
 
   /// \brief Bitwise OR assignment operator.
@@ -796,11 +797,11 @@ public:
   /// \returns *this after XORing with RHS.
   APInt &operator^=(const APInt &RHS) {
     assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
-    if (isSingleWord()) {
+    if (isSingleWord())
       VAL ^= RHS.VAL;
-      return *this;
-    }
-    return XorAssignSlowCase(RHS);
+    else
+      XorAssignSlowCase(RHS);
+    return *this;
   }
 
   /// \brief Bitwise XOR assignment operator.
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 6303dd8..ad964e2 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -125,16 +125,16 @@ APInt::APInt(unsigned numbits, StringRef Str, uint8_t radix)
   fromString(numbits, Str, radix);
 }
 
-APInt& APInt::AssignSlowCase(const APInt& RHS) {
+void APInt::AssignSlowCase(const APInt& RHS) {
   // Don't do anything for X = X
   if (this == &RHS)
-    return *this;
+    return;
 
   if (BitWidth == RHS.getBitWidth()) {
     // assume same bit-width single-word case is already handled
     assert(!isSingleWord());
     memcpy(pVal, RHS.pVal, getNumWords() * APINT_WORD_SIZE);
-    return *this;
+    return;
   }
 
   if (isSingleWord()) {
@@ -154,7 +154,7 @@ APInt& APInt::AssignSlowCase(const APInt& RHS) {
     memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE);
   }
   BitWidth = RHS.BitWidth;
-  return clearUnusedBits();
+  clearUnusedBits();
 }
 
 /// This method 'profiles' an APInt for use with FoldingSet.
@@ -339,19 +339,16 @@ APInt& APInt::operator*=(const APInt& RHS) {
   return *this;
 }
 
-APInt& APInt::AndAssignSlowCase(const APInt& RHS) {
+void APInt::AndAssignSlowCase(const APInt& RHS) {
   tcAnd(pVal, RHS.pVal, getNumWords());
-  return *this;
 }
 
-APInt& APInt::OrAssignSlowCase(const APInt& RHS) {
+void APInt::OrAssignSlowCase(const APInt& RHS) {
   tcOr(pVal, RHS.pVal, getNumWords());
-  return *this;
 }
 
-APInt& APInt::XorAssignSlowCase(const APInt& RHS) {
+void APInt::XorAssignSlowCase(const APInt& RHS) {
   tcXor(pVal, RHS.pVal, getNumWords());
-  return *this;
 }
 
 APInt APInt::operator*(const APInt& RHS) const {
-- 
2.7.4