Make the popcnt support enums and methods have more clear names and

follow the conding conventions regarding enumerating a set of "kinds" of
things.

llvm-svn: 171687

llvm/include/llvm/Analysis/TargetTransformInfo.h

@@ -70,16 +70,18 @@ public:
   /// \name Scalar Target Information
   /// @{
 
-  /// PopcntHwSupport - Hardware support for population count. Compared to the
-  /// SW implementation, HW support is supposed to significantly boost the
-  /// performance when the population is dense, and it may or may not degrade
-  /// performance if the population is sparse. A HW support is considered as
-  /// "Fast" if it can outperform, or is on a par with, SW implementaion when
-  /// the population is sparse; otherwise, it is considered as "Slow".
-  enum PopcntHwSupport {
-    None,
-    Fast,
-    Slow
+  /// \brief Flags indicating the kind of support for population count.
+  ///
+  /// Compared to the SW implementation, HW support is supposed to
+  /// significantly boost the performance when the population is dense, and it
+  /// may or may not degrade performance if the population is sparse. A HW
+  /// support is considered as "Fast" if it can outperform, or is on a par
+  /// with, SW implementaion when the population is sparse; otherwise, it is
+  /// considered as "Slow".
+  enum PopcntSupportKind {
+    PSK_Software,
+    PSK_SlowHardware,
+    PSK_FastHardware
   };
 
   /// isLegalAddImmediate - Return true if the specified immediate is legal
@@ -121,8 +123,8 @@ public:
   /// lookup tables for the target.
   virtual bool shouldBuildLookupTables() const;
 
-  /// getPopcntHwSupport - Return hardware support for population count.
-  virtual PopcntHwSupport getPopcntHwSupport(unsigned IntTyWidthInBit) const;
+  /// getPopcntSupport - Return hardware support for population count.
+  virtual PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) const;
 
   /// getIntImmCost - Return the expected cost of materializing the given
   /// integer immediate of the specified type.

llvm/lib/Analysis/TargetTransformInfo.cpp

@@ -79,9 +79,9 @@ bool TargetTransformInfo::shouldBuildLookupTables() const {
   return PrevTTI->shouldBuildLookupTables();
 }
 
-TargetTransformInfo::PopcntHwSupport
-TargetTransformInfo::getPopcntHwSupport(unsigned IntTyWidthInBit) const {
-  return PrevTTI->getPopcntHwSupport(IntTyWidthInBit);
+TargetTransformInfo::PopcntSupportKind
+TargetTransformInfo::getPopcntSupport(unsigned IntTyWidthInBit) const {
+  return PrevTTI->getPopcntSupport(IntTyWidthInBit);
 }
 
 unsigned TargetTransformInfo::getIntImmCost(const APInt &Imm, Type *Ty) const {
@@ -202,8 +202,8 @@ struct NoTTI : ImmutablePass, TargetTransformInfo {
     return true;
   }
 
-  PopcntHwSupport getPopcntHwSupport(unsigned IntTyWidthInBit) const {
-    return None;
+  PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) const {
+    return PSK_Software;
   }
 
   unsigned getIntImmCost(const APInt &Imm, Type *Ty) const {

llvm/lib/Target/X86/X86TargetTransformInfo.cpp

@@ -76,7 +76,7 @@ public:
   /// \name Scalar TTI Implementations
   /// @{
 
-  virtual PopcntHwSupport getPopcntHwSupport(unsigned TyWidth) const;
+  virtual PopcntSupportKind getPopcntSupport(unsigned TyWidth) const;
 
   /// @}
 
@@ -157,12 +157,12 @@ FindInConvertTable(const X86TypeConversionCostTblEntry *Tbl, unsigned len,
 }
 
 
-X86TTI::PopcntHwSupport X86TTI::getPopcntHwSupport(unsigned TyWidth) const {
+X86TTI::PopcntSupportKind X86TTI::getPopcntSupport(unsigned TyWidth) const {
   assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2");
   // TODO: Currently the __builtin_popcount() implementation using SSE3
   //   instructions is inefficient. Once the problem is fixed, we should
   //   call ST->hasSSE3() instead of ST->hasSSE4().
-  return ST->hasSSE41() ? Fast : None;
+  return ST->hasSSE41() ? PSK_FastHardware : PSK_Software;
 }
 
 unsigned X86TTI::getNumberOfRegisters(bool Vector) const {

llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

@@ -311,7 +311,7 @@ NclPopcountRecognize::NclPopcountRecognize(LoopIdiomRecognize &TheLIR):
 
 bool NclPopcountRecognize::preliminaryScreen() {
   const TargetTransformInfo *TTI = LIR.getTargetTransformInfo();
-  if (TTI->getPopcntHwSupport(32) != TargetTransformInfo::Fast)
+  if (TTI->getPopcntSupport(32) != TargetTransformInfo::PSK_FastHardware)
     return false;
 
   // Counting population are usually conducted by few arithmetic instrutions.