Change how extended types are represented in MVTs. Instead of fiddling

bits, use a union of a SimpleValueType enum and a regular Type*.

This increases the size of MVT on 64-bit hosts from 32 bits to 64 bits.
In most cases, this doesn't add significant overhead. There are places
in codegen that use arrays of MVTs, so these are now larger, but
they're small in common cases.

This eliminates restrictions on the size of integer types and vector
types that can be represented in codegen. As the included testcase
demonstrates, it's now possible to codegen very large add operations.
There are still some complications with using very large types. PR2880
is still open so they can't be used as return values on normal targets,
there are no libcalls defined for very large integers so operations
like multiply and divide aren't supported.

This also introduces a minimal tablgen Type library, capable of
handling IntegerType and VectorType. This will allow parts of
TableGen that don't depend on using SimpleValueType values to handle
arbitrary integer and vector types.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58623 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 124 insertions, 0 deletions

diff --git a/utils/TableGen/CMakeLists.txt b/utils/TableGen/CMakeLists.txt
index 8141d76..8e6a3e1 100644
--- a/utils/TableGen/CMakeLists.txt
+++ b/utils/TableGen/CMakeLists.txt
@@ -15,6 +15,7 @@ add_executable(tblgen
   SubtargetEmitter.cpp
   TGLexer.cpp
   TGParser.cpp
+  TGValueTypes.cpp
   TableGen.cpp
   TableGenBackend.cpp
   FastISelEmitter.cpp
diff --git a/utils/TableGen/TGValueTypes.cpp b/utils/TableGen/TGValueTypes.cpp
new file mode 100644
index 0000000..209e7c9
--- /dev/null
+++ b/utils/TableGen/TGValueTypes.cpp
@@ -0,0 +1,123 @@
+//===- ValueTypes.cpp - Tablegen extended ValueType implementation --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The MVT type is used by tablegen as well as in LLVM. In order to handle
+// extended types, the MVT type uses support functions that call into
+// LLVM's type system code. These aren't accessible in tablegen, so this
+// file provides simple replacements.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/Support/Streams.h"
+#include <map>
+#include <vector>
+using namespace llvm;
+
+namespace llvm {
+
+class Type {
+public:
+  virtual unsigned getSizeInBits() const = 0;
+};
+
+}
+
+class ExtendedIntegerType : public Type {
+  unsigned BitWidth;
+public:
+  explicit ExtendedIntegerType(unsigned bits)
+    : BitWidth(bits) {}
+  unsigned getSizeInBits() const {
+    return getBitWidth();
+  }
+  unsigned getBitWidth() const {
+    return BitWidth;
+  }
+};
+
+class ExtendedVectorType : public Type {
+  MVT ElementType;
+  unsigned NumElements;
+public:
+  ExtendedVectorType(MVT elty, unsigned num)
+    : ElementType(elty), NumElements(num) {}
+  unsigned getSizeInBits() const {
+    return getNumElements() * getElementType().getSizeInBits();
+  }
+  MVT getElementType() const {
+    return ElementType;
+  }
+  unsigned getNumElements() const {
+    return NumElements;
+  }
+};
+
+static std::map<unsigned, const Type *>
+  ExtendedIntegerTypeMap;
+static std::map<std::pair<uintptr_t, uintptr_t>, const Type *>
+  ExtendedVectorTypeMap;
+
+MVT MVT::getExtendedIntegerVT(unsigned BitWidth) {
+  const Type *&ET = ExtendedIntegerTypeMap[BitWidth];
+  if (!ET) ET = new ExtendedIntegerType(BitWidth);
+  MVT VT;
+  VT.LLVMTy = ET;
+  return VT;
+}
+
+MVT MVT::getExtendedVectorVT(MVT VT, unsigned NumElements) {
+  const Type *&ET = ExtendedVectorTypeMap[std::make_pair(VT.getRawBits(),
+                                                         NumElements)];
+  if (!ET) ET = new ExtendedVectorType(VT, NumElements);
+  MVT ResultVT;
+  ResultVT.LLVMTy = ET;
+  return ResultVT;
+}
+
+bool MVT::isExtendedFloatingPoint() const {
+  assert(isExtended() && "Type is not extended!");
+  // Extended floating-point types are not supported yet.
+  return false;
+}
+
+bool MVT::isExtendedInteger() const {
+  assert(isExtended() && "Type is not extended!");
+  return dynamic_cast<const ExtendedIntegerType *>(LLVMTy) != 0;
+}
+
+bool MVT::isExtendedVector() const {
+  assert(isExtended() && "Type is not extended!");
+  return dynamic_cast<const ExtendedVectorType *>(LLVMTy) != 0;
+}
+
+bool MVT::isExtended64BitVector() const {
+  assert(isExtended() && "Type is not extended!");
+  return isExtendedVector() && getSizeInBits() == 64;
+}
+
+bool MVT::isExtended128BitVector() const {
+  assert(isExtended() && "Type is not extended!");
+  return isExtendedVector() && getSizeInBits() == 128;
+}
+
+MVT MVT::getExtendedVectorElementType() const {
+  assert(isExtendedVector() && "Type is not an extended vector!");
+  return static_cast<const ExtendedVectorType *>(LLVMTy)->getElementType();
+}
+
+unsigned MVT::getExtendedVectorNumElements() const {
+  assert(isExtendedVector() && "Type is not an extended vector!");
+  return static_cast<const ExtendedVectorType *>(LLVMTy)->getNumElements();
+}
+
+unsigned MVT::getExtendedSizeInBits() const {
+  assert(isExtended() && "Type is not extended!");
+  return LLVMTy->getSizeInBits();
+}