TableGen/SearchableTables: Support more generic enums and tables
Summary:
This is essentially a rewrite of the backend which introduces TableGen
base classes GenericEnum, GenericTable, and SearchIndex. They allow
generating custom enums and tables with lookup functions using
separately defined records as the underlying database.
Also added as part of this change:
- Lookup functions may use indices composed of multiple fields.
- Instruction fields are supported similar to Intrinsic fields.
- When the lookup key has contiguous numeric values, the lookup
function will directly index into the table instead of using a binary
search.
The existing SearchableTable functionality is internally mapped to the
new primitives.
Change-Id: I444f3490fa1dbfb262d7286a1660a2c4308e9932
Reviewers: arsenm, tra, t.p.northover
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D48013
llvm-svn: 335225
diff --git a/llvm/docs/TableGen/BackEnds.rst b/llvm/docs/TableGen/BackEnds.rst
index 9931343..a39ea61 100644
--- a/llvm/docs/TableGen/BackEnds.rst
+++ b/llvm/docs/TableGen/BackEnds.rst
@@ -221,6 +221,22 @@
**Purpose**: Print enum values for a class.
+SearchableTables
+----------------
+
+**Purpose**: Generate custom searchable tables.
+
+**Output**: Enums, global tables and lookup helper functions.
+
+**Usage**: This backend allows generating free-form, target-specific tables
+from TableGen records. The ARM and AArch64 targets use this backend to generate
+tables of system registers; the AMDGPU target uses it to generate meta-data
+about complex image and memory buffer instructions.
+
+More documentation is available in ``include/llvm/TableGen/SearchableTable.td``,
+which also contains the definitions of TableGen classes which must be
+instantiated in order to define the enums and tables emitted by this backend.
+
CTags
-----