[llvm-commits] [PATCH] Rename isPowerOfTwo to isKnownToBeAPowerOfTwo.

[Rafael Ávila de Espíndola]

In a previous thread it was pointed out that isPowerOfTwo is not a very precise
name since it can return false for powers of two if it is unable to show that
they are powers of two.

The best same so far is isKnownToBeAPowerOfTwo.
---
 include/llvm/Analysis/ValueTracking.h              | 12 ++++++------
 lib/Analysis/InstructionSimplify.cpp               |  4 ++--
 lib/Analysis/ValueTracking.cpp                     | 22 +++++++++++-----------
 .../InstCombine/InstCombineMulDivRem.cpp           |  4 ++--
 4 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/include/llvm/Analysis/ValueTracking.h b/include/llvm/Analysis/ValueTracking.h
index 73ce4bc..875c47d 100644
--- a/include/llvm/Analysis/ValueTracking.h
+++ b/include/llvm/Analysis/ValueTracking.h
@@ -45,12 +45,12 @@ namespace llvm {
   void ComputeSignBit(Value *V, bool &KnownZero, bool &KnownOne,
                       const DataLayout *TD = 0, unsigned Depth = 0);
 
-  /// isPowerOfTwo - Return true if the given value is known to have exactly one
-  /// bit set when defined. For vectors return true if every element is known to
-  /// be a power of two when defined.  Supports values with integer or pointer
-  /// type and vectors of integers.  If 'OrZero' is set then returns true if the
-  /// given value is either a power of two or zero.
-  bool isPowerOfTwo(Value *V, bool OrZero = false, unsigned Depth = 0);
+  /// isKnownToBeAPowerOfTwo - Return true if the given value is known to have
+  /// exactly one bit set when defined. For vectors return true if every
+  /// element is known to be a power of two when defined.  Supports values with
+  /// integer or pointer type and vectors of integers.  If 'OrZero' is set then
+  /// returns true if the given value is either a power of two or zero.
+  bool isKnownToBeAPowerOfTwo(Value *V, bool OrZero = false, unsigned Depth = 0);
 
   /// isKnownNonZero - Return true if the given value is known to be non-zero
   /// when defined.  For vectors return true if every element is known to be
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 2bcd363..0b88f45 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1457,9 +1457,9 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
   // A & (-A) = A if A is a power of two or zero.
   if (match(Op0, m_Neg(m_Specific(Op1))) ||
       match(Op1, m_Neg(m_Specific(Op0)))) {
-    if (isPowerOfTwo(Op0, /*OrZero*/true))
+    if (isKnownToBeAPowerOfTwo(Op0, /*OrZero*/true))
       return Op0;
-    if (isPowerOfTwo(Op1, /*OrZero*/true))
+    if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true))
       return Op1;
   }
 
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 5a48c3d..b86bc37 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -799,11 +799,11 @@ void llvm::ComputeSignBit(Value *V, bool &KnownZero, bool &KnownOne,
   KnownZero = ZeroBits[BitWidth - 1];
 }
 
-/// isPowerOfTwo - Return true if the given value is known to have exactly one
+/// isKnownToBeAPowerOfTwo - Return true if the given value is known to have exactly one
 /// bit set when defined. For vectors return true if every element is known to
 /// be a power of two when defined.  Supports values with integer or pointer
 /// types and vectors of integers.
-bool llvm::isPowerOfTwo(Value *V, bool OrZero, unsigned Depth) {
+bool llvm::isKnownToBeAPowerOfTwo(Value *V, bool OrZero, unsigned Depth) {
   if (Constant *C = dyn_cast<Constant>(V)) {
     if (C->isNullValue())
       return OrZero;
@@ -830,19 +830,19 @@ bool llvm::isPowerOfTwo(Value *V, bool OrZero, unsigned Depth) {
   // A shift of a power of two is a power of two or zero.
   if (OrZero && (match(V, m_Shl(m_Value(X), m_Value())) ||
                  match(V, m_Shr(m_Value(X), m_Value()))))
-    return isPowerOfTwo(X, /*OrZero*/true, Depth);
+    return isKnownToBeAPowerOfTwo(X, /*OrZero*/true, Depth);
 
   if (ZExtInst *ZI = dyn_cast<ZExtInst>(V))
-    return isPowerOfTwo(ZI->getOperand(0), OrZero, Depth);
+    return isKnownToBeAPowerOfTwo(ZI->getOperand(0), OrZero, Depth);
 
   if (SelectInst *SI = dyn_cast<SelectInst>(V))
-    return isPowerOfTwo(SI->getTrueValue(), OrZero, Depth) &&
-      isPowerOfTwo(SI->getFalseValue(), OrZero, Depth);
+    return isKnownToBeAPowerOfTwo(SI->getTrueValue(), OrZero, Depth) &&
+      isKnownToBeAPowerOfTwo(SI->getFalseValue(), OrZero, Depth);
 
   if (OrZero && match(V, m_And(m_Value(X), m_Value(Y)))) {
     // A power of two and'd with anything is a power of two or zero.
-    if (isPowerOfTwo(X, /*OrZero*/true, Depth) ||
-        isPowerOfTwo(Y, /*OrZero*/true, Depth))
+    if (isKnownToBeAPowerOfTwo(X, /*OrZero*/true, Depth) ||
+        isKnownToBeAPowerOfTwo(Y, /*OrZero*/true, Depth))
       return true;
     // X & (-X) is always a power of two or zero.
     if (match(X, m_Neg(m_Specific(Y))) || match(Y, m_Neg(m_Specific(X))))
@@ -855,7 +855,7 @@ bool llvm::isPowerOfTwo(Value *V, bool OrZero, unsigned Depth) {
   // copying a sign bit (sdiv int_min, 2).
   if (match(V, m_Exact(m_LShr(m_Value(), m_Value()))) ||
       match(V, m_Exact(m_UDiv(m_Value(), m_Value())))) {
-    return isPowerOfTwo(cast<Operator>(V)->getOperand(0), OrZero, Depth);
+    return isKnownToBeAPowerOfTwo(cast<Operator>(V)->getOperand(0), OrZero, Depth);
   }
 
   return false;
@@ -1027,9 +1027,9 @@ bool llvm::isKnownNonZero(Value *V, const DataLayout *TD, unsigned Depth) {
     }
 
     // The sum of a non-negative number and a power of two is not zero.
-    if (XKnownNonNegative && isPowerOfTwo(Y, /*OrZero*/false, Depth))
+    if (XKnownNonNegative && isKnownToBeAPowerOfTwo(Y, /*OrZero*/false, Depth))
       return true;
-    if (YKnownNonNegative && isPowerOfTwo(X, /*OrZero*/false, Depth))
+    if (YKnownNonNegative && isKnownToBeAPowerOfTwo(X, /*OrZero*/false, Depth))
       return true;
   }
   // X * Y.
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 019596c..b95da85 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -37,7 +37,7 @@ static Value *simplifyValueKnownNonZero(Value *V, InstCombiner &IC) {
   if (match(V, m_LShr(m_OneUse(m_Shl(m_Value(PowerOf2), m_Value(A))),
                       m_Value(B))) &&
       // The "1" can be any value known to be a power of 2.
-      isPowerOfTwo(PowerOf2)) {
+      isKnownToBeAPowerOfTwo(PowerOf2)) {
     A = IC.Builder->CreateSub(A, B);
     return IC.Builder->CreateShl(PowerOf2, A);
   }
@@ -45,7 +45,7 @@ static Value *simplifyValueKnownNonZero(Value *V, InstCombiner &IC) {
   // (PowerOfTwo >>u B) --> isExact since shifting out the result would make it
   // inexact.  Similarly for <<.
   if (BinaryOperator *I = dyn_cast<BinaryOperator>(V))
-    if (I->isLogicalShift() && isPowerOfTwo(I->getOperand(0))) {
+    if (I->isLogicalShift() && isKnownToBeAPowerOfTwo(I->getOperand(0))) {
       // We know that this is an exact/nuw shift and that the input is a
       // non-zero context as well.
       if (Value *V2 = simplifyValueKnownNonZero(I->getOperand(0), IC)) {
-- 
1.7.11.7