Fix undefined behavior.

[oota-llvm.git] / lib / Support / APInt.cpp

diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index 143ded920e217b1c03ce2658b38f011521863554..0d4e0f9f752aff20b341283196aacadcb2e871b8 100644 (file)
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -1123,6 +1123,18 @@ APInt APInt::sextOrTrunc(unsigned width) const {
   return *this;
 }
 
   return *this;
 }
 

+APInt APInt::zextOrSelf(unsigned width) const {
+  if (BitWidth < width)
+    return zext(width);
+  return *this;
+}
+
+APInt APInt::sextOrSelf(unsigned width) const {
+  if (BitWidth < width)
+    return sext(width);
+  return *this;
+}
+

 /// Arithmetic right-shift this APInt by shiftAmt.
 /// @brief Arithmetic right-shift function.
 APInt APInt::ashr(const APInt &shiftAmt) const {
 /// Arithmetic right-shift this APInt by shiftAmt.
 /// @brief Arithmetic right-shift function.
 APInt APInt::ashr(const APInt &shiftAmt) const {


@@ -1222,7 +1234,7 @@ APInt APInt::lshr(const APInt &shiftAmt) const {
 /// @brief Logical right-shift function.
 APInt APInt::lshr(unsigned shiftAmt) const {
   if (isSingleWord()) {
 /// @brief Logical right-shift function.
 APInt APInt::lshr(unsigned shiftAmt) const {
   if (isSingleWord()) {

-    if (shiftAmt == BitWidth)
+    if (shiftAmt >= BitWidth)

       return APInt(BitWidth, 0);
     else
       return APInt(BitWidth, this->VAL >> shiftAmt);
       return APInt(BitWidth, 0);
     else
       return APInt(BitWidth, this->VAL >> shiftAmt);


@@ -1338,14 +1350,10 @@ APInt APInt::rotl(const APInt &rotateAmt) const {
 }
 
 APInt APInt::rotl(unsigned rotateAmt) const {
 }
 
 APInt APInt::rotl(unsigned rotateAmt) const {

+  rotateAmt %= BitWidth;

   if (rotateAmt == 0)
     return *this;
   if (rotateAmt == 0)
     return *this;

-  // Don't get too fancy, just use existing shift/or facilities
-  APInt hi(*this);
-  APInt lo(*this);
-  hi.shl(rotateAmt);
-  lo.lshr(BitWidth - rotateAmt);
-  return hi | lo;
+  return shl(rotateAmt) | lshr(BitWidth - rotateAmt);

 }
 
 APInt APInt::rotr(const APInt &rotateAmt) const {
 }
 
 APInt APInt::rotr(const APInt &rotateAmt) const {


@@ -1353,14 +1361,10 @@ APInt APInt::rotr(const APInt &rotateAmt) const {
 }
 
 APInt APInt::rotr(unsigned rotateAmt) const {
 }
 
 APInt APInt::rotr(unsigned rotateAmt) const {

+  rotateAmt %= BitWidth;

   if (rotateAmt == 0)
     return *this;
   if (rotateAmt == 0)
     return *this;

-  // Don't get too fancy, just use existing shift/or facilities
-  APInt hi(*this);
-  APInt lo(*this);
-  lo.lshr(rotateAmt);
-  hi.shl(BitWidth - rotateAmt);
-  return hi | lo;
+  return lshr(rotateAmt) | shl(BitWidth - rotateAmt);

 }
 
 // Square Root - this method computes and returns the square root of "this".
 }
 
 // Square Root - this method computes and returns the square root of "this".