Introduction of improved switch lowering.

src/IceTypes.cpp

 //===- subzero/src/IceTypes.cpp - Primitive type properties ---------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 12 matching lines @@
 const char *TargetArchName[] = {
 #define X(tag, str, is_elf64, e_machine, e_flags) str,
     TARGETARCH_TABLE
 #undef X
 };
 
 // Show tags match between ICETYPE_TABLE and ICETYPE_PROPS_TABLE.
 
 // Define a temporary set of enum values based on ICETYPE_TABLE
 enum {
-#define X(tag, size, align, elts, elty, str) _table_tag_##tag,
+#define X(tag, sizeLog2, align, elts, elty, str) _table_tag_##tag,
   ICETYPE_TABLE
 #undef X
       _enum_table_tag_Names
 };
 // Define a temporary set of enum values based on ICETYPE_PROPS_TABLE
 enum {
 #define X(tag, IsVec, IsInt, IsFloat, IsIntArith, IsLoadStore, CompareResult)  \
   _props_table_tag_##tag,
   ICETYPE_PROPS_TABLE
 #undef X
       _enum_props_table_tag_Names
 };
 // Assert that tags in ICETYPE_TABLE are also in ICETYPE_PROPS_TABLE.
-#define X(tag, size, align, elts, elty, str)                                   \
+#define X(tag, sizeLog2, align, elts, elty, str)                               \
   static_assert(                                                               \
       (unsigned)_table_tag_##tag == (unsigned)_props_table_tag_##tag,          \
       "Inconsistency between ICETYPE_PROPS_TABLE and ICETYPE_TABLE");
 ICETYPE_TABLE
 #undef X
 // Assert that tags in ICETYPE_PROPS_TABLE is in ICETYPE_TABLE.
 #define X(tag, IsVec, IsInt, IsFloat, IsIntArith, IsLoadStore, CompareResult)  \
   static_assert(                                                               \
       (unsigned)_table_tag_##tag == (unsigned)_props_table_tag_##tag,          \
       "Inconsistency between ICETYPE_PROPS_TABLE and ICETYPE_TABLE");
 ICETYPE_PROPS_TABLE
 #undef X
 
 // Show vector definitions match in ICETYPE_TABLE and
 // ICETYPE_PROPS_TABLE.
 
 // Define constants for each element size in ICETYPE_TABLE.
 enum {
-#define X(tag, size, align, elts, elty, str) _table_elts_##tag = elts,
+#define X(tag, sizeLog2, align, elts, elty, str) _table_elts_##tag = elts,
   ICETYPE_TABLE
 #undef X
       _enum_table_elts_Elements = 0
 };
 // Define constants for boolean flag if vector in ICETYPE_PROPS_TABLE.
 enum {
 #define X(tag, IsVec, IsInt, IsFloat, IsIntArith, IsLoadStore, CompareResult)  \
   _props_table_IsVec_##tag = IsVec,
   ICETYPE_PROPS_TABLE
 #undef X
 };
 // Verify that the number of vector elements is consistent with IsVec.
 #define X(tag, IsVec, IsInt, IsFloat, IsIntArith, IsLoadStore, CompareResult)  \
   static_assert((_table_elts_##tag > 1) == _props_table_IsVec_##tag,           \
                 "Inconsistent vector specification in ICETYPE_PROPS_TABLE");
 ICETYPE_PROPS_TABLE
 #undef X
 
 struct TypeAttributeFields {
-  size_t TypeWidthInBytes;
+  int8_t TypeWidthInBytesLog2;
   size_t TypeAlignInBytes;
   size_t TypeNumElements;
   Type TypeElementType;
   const char *DisplayString;
 };
 
 const struct TypeAttributeFields TypeAttributes[] = {
-#define X(tag, size, align, elts, elty, str)                                   \
-  { size, align, elts, elty, str }                                             \
+#define X(tag, sizeLog2, align, elts, elty, str)                               \
+  { sizeLog2, align, elts, elty, str }                                         \
   ,
     ICETYPE_TABLE
 #undef X
 };
 
 struct TypePropertyFields {
   bool TypeIsVectorType;
   bool TypeIsIntegerType;
   bool TypeIsScalarIntegerType;
   bool TypeIsVectorIntegerType;
@@ skipping 20 matching lines @@
 
 const char *targetArchString(const TargetArch Arch) {
   size_t Index = static_cast<size_t>(Arch);
   if (Index < TargetArch_NUM)
     return TargetArchName[Index];
   llvm_unreachable("Invalid target arch for targetArchString");
   return "???";
 }
 
 size_t typeWidthInBytes(Type Ty) {
+  int8_t Shift = typeWidthInBytesLog2(Ty);
+  return (Shift < 0) ? 0 : 1 << Shift;
+}
+
+int8_t typeWidthInBytesLog2(Type Ty) {
   size_t Index = static_cast<size_t>(Ty);
   if (Index < IceType_NUM)
-    return TypeAttributes[Index].TypeWidthInBytes;
-  llvm_unreachable("Invalid type for typeWidthInBytes()");
+    return TypeAttributes[Index].TypeWidthInBytesLog2;
+  llvm_unreachable("Invalid type for typeWidthInBytesLog2()");
   return 0;
 }
 
 size_t typeAlignInBytes(Type Ty) {
   size_t Index = static_cast<size_t>(Ty);
   if (Index < IceType_NUM)
     return TypeAttributes[Index].TypeAlignInBytes;
   llvm_unreachable("Invalid type for typeAlignInBytes()");
   return 1;
 }
@@ skipping 121 matching lines @@
       IsFirst = false;
     } else {
       Stream << ", ";
     }
     Stream << ArgTy;
   }
   Stream << ")";
 }
 
 } // end of namespace Ice