From 19dc32a2d422ac0aafd047514e3e5e727796696e Mon Sep 17 00:00:00 2001
From: Reid Spencer <rspencer@reidspencer.com>
Date: Sun, 13 May 2007 23:44:59 +0000
Subject: Add some things needed by the llvm-gcc version supporting bit
 accurate integer types: 1. Functions to compute div/rem at the same time. 2.
 Further assurance that an APInt with 0 bitwidth cannot be constructed. 3.
 Left and right rotate operations. 4. An exactLogBase2 function which requires
 an exact power of two or it    returns -1.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37025 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/APInt.h | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

(limited to 'include/llvm/ADT')

diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index 36ced6f..535e5db 100644
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -567,6 +567,12 @@ public:
   /// @brief Left-shift function.
   APInt shl(uint32_t shiftAmt) const;
 
+  /// @brief Rotate left by rotateAmt.
+  APInt rotl(uint32_t rotateAmt) const;
+
+  /// @brief Rotate right by rotateAmt.
+  APInt rotr(uint32_t rotateAmt) const;
+
   /// Perform an unsigned divide operation on this APInt by RHS. Both this and
   /// RHS are treated as unsigned quantities for purposes of this division.
   /// @returns a new APInt value containing the division result
@@ -608,6 +614,31 @@ public:
     return this->urem(RHS);
   }
 
+  /// Sometimes it is convenient to divide two APInt values and obtain both
+  /// the quotient and remainder. This function does both operations in the
+  /// same computation making it a little more efficient.
+  /// @brief Dual division/remainder interface.
+  static void udivrem(const APInt &LHS, const APInt &RHS, 
+                      APInt &Quotient, APInt &Remainder);
+
+  static void sdivrem(const APInt &LHS, const APInt &RHS,
+                      APInt &Quotient, APInt &Remainder)
+  {
+    if (LHS.isNegative()) {
+      if (RHS.isNegative())
+        APInt::udivrem(-LHS, -RHS, Quotient, Remainder);
+      else
+        APInt::udivrem(-LHS, RHS, Quotient, Remainder);
+      Quotient = -Quotient;
+      Remainder = -Remainder;
+    } else if (RHS.isNegative()) {
+      APInt::udivrem(LHS, -RHS, Quotient, Remainder);
+      Quotient = -Quotient;
+    } else {
+      APInt::udivrem(LHS, RHS, Quotient, Remainder);
+    }
+  }
+
   /// @returns the bit value at bitPosition
   /// @brief Array-indexing support.
   bool operator[](uint32_t bitPosition) const;
@@ -988,6 +1019,14 @@ public:
     return BitWidth - 1 - countLeadingZeros();
   }
 
+  /// @returns the log base 2 of this APInt if its an exact power of two, -1
+  /// otherwise
+  inline int32_t exactLogBase2() const {
+    if (!isPowerOf2())
+      return -1;
+    return logBase2();
+  }
+
   /// @brief Compute the square root
   APInt sqrt() const;
 
-- 
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