Hoist the definition of getTypeSizeInBits to be inlinable and in the

header.

This method is called in the hot path for *many* passes, SROA is what
caught my interest. A common pattern is that which branch of the switch
should be taken is known in the callsite and so it is a very good
candidate for inlining and simplification. Moving it into the header
allows the optimizer to fold a lot of boring, repeatitive code in
callers of this routine.

I'm seeing pretty significant speedups in parts of SROA and I suspect
other passes will see similar speedups if they end up working with type
sizes frequently. I've not seen any significant growth of the binaries
as a consequence, but let me know if you see anything suspicious here.

llvm-svn: 177632

llvm/include/llvm/IR/DataLayout.h

@@ -22,6 +22,8 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Type.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/DataTypes.h"
 
@@ -423,6 +425,49 @@ private:
   StructLayout(StructType *ST, const DataLayout &TD);
 };
 
+
+// The implementation of this method is provided inline as it is particularly
+// well suited to constant folding when called on a specific Type subclass.
+inline uint64_t DataLayout::getTypeSizeInBits(Type *Ty) const {
+  assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
+  switch (Ty->getTypeID()) {
+  case Type::LabelTyID:
+    return getPointerSizeInBits(0);
+  case Type::PointerTyID:
+    return getPointerSizeInBits(cast<PointerType>(Ty)->getAddressSpace());
+  case Type::ArrayTyID: {
+    ArrayType *ATy = cast<ArrayType>(Ty);
+    return ATy->getNumElements() *
+           getTypeAllocSizeInBits(ATy->getElementType());
+  }
+  case Type::StructTyID:
+    // Get the layout annotation... which is lazily created on demand.
+    return getStructLayout(cast<StructType>(Ty))->getSizeInBits();
+  case Type::IntegerTyID:
+    return cast<IntegerType>(Ty)->getBitWidth();
+  case Type::HalfTyID:
+    return 16;
+  case Type::FloatTyID:
+    return 32;
+  case Type::DoubleTyID:
+  case Type::X86_MMXTyID:
+    return 64;
+  case Type::PPC_FP128TyID:
+  case Type::FP128TyID:
+    return 128;
+    // In memory objects this is always aligned to a higher boundary, but
+  // only 80 bits contain information.
+  case Type::X86_FP80TyID:
+    return 80;
+  case Type::VectorTyID: {
+    VectorType *VTy = cast<VectorType>(Ty);
+    return VTy->getNumElements() * getTypeSizeInBits(VTy->getElementType());
+  }
+  default:
+    llvm_unreachable("DataLayout::getTypeSizeInBits(): Unsupported type");
+  }
+}
+
 } // End llvm namespace
 
 #endif

llvm/lib/IR/DataLayout.cpp

@@ -510,47 +510,6 @@ std::string DataLayout::getStringRepresentation() const {
 }
 
 
-uint64_t DataLayout::getTypeSizeInBits(Type *Ty) const {
-  assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
-  switch (Ty->getTypeID()) {
-  case Type::LabelTyID:
-    return getPointerSizeInBits(0);
-  case Type::PointerTyID: {
-    unsigned AS = dyn_cast<PointerType>(Ty)->getAddressSpace();
-    return getPointerSizeInBits(AS);
-  }
-  case Type::ArrayTyID: {
-    ArrayType *ATy = cast<ArrayType>(Ty);
-    return getTypeAllocSizeInBits(ATy->getElementType())*ATy->getNumElements();
-  }
-  case Type::StructTyID:
-    // Get the layout annotation... which is lazily created on demand.
-    return getStructLayout(cast<StructType>(Ty))->getSizeInBits();
-  case Type::IntegerTyID:
-    return cast<IntegerType>(Ty)->getBitWidth();
-  case Type::HalfTyID:
-    return 16;
-  case Type::FloatTyID:
-    return 32;
-  case Type::DoubleTyID:
-  case Type::X86_MMXTyID:
-    return 64;
-  case Type::PPC_FP128TyID:
-  case Type::FP128TyID:
-    return 128;
-  // In memory objects this is always aligned to a higher boundary, but
-  // only 80 bits contain information.
-  case Type::X86_FP80TyID:
-    return 80;
-  case Type::VectorTyID: {
-    VectorType *VTy = cast<VectorType>(Ty);
-    return VTy->getNumElements()*getTypeSizeInBits(VTy->getElementType());
-  }
-  default:
-    llvm_unreachable("DataLayout::getTypeSizeInBits(): Unsupported type");
-  }
-}
-
 /*!
   \param abi_or_pref Flag that determines which alignment is returned. true
   returns the ABI alignment, false returns the preferred alignment.