From 6f083a310ad267cab38eab45116a49b81eceaeff Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <jolesen@mozilla.com>
Date: Tue, 5 Apr 2016 14:35:50 -0700
Subject: [PATCH] Collect all instructions into instruction groups.

---
 docs/metaref.rst          |  2 ++
 meta/cretonne/__init__.py | 45 +++++++++++++++++++++++++++++++++++++++
 meta/cretonne/base.py     |  6 +++++-
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/docs/metaref.rst b/docs/metaref.rst
index 8d58757b81..e9b7c9a6ec 100644
--- a/docs/metaref.rst
+++ b/docs/metaref.rst
@@ -72,3 +72,5 @@ class.
 
 .. autoclass:: Operand
 .. autoclass:: Instruction
+.. autoclass:: InstructionGroup
+    :members:
diff --git a/meta/cretonne/__init__.py b/meta/cretonne/__init__.py
index bbf0e74063..a5ebb50f04 100644
--- a/meta/cretonne/__init__.py
+++ b/meta/cretonne/__init__.py
@@ -150,6 +150,50 @@ class ImmediateType(object):
 # Defining instructions.
 #
 
+class InstructionGroup(object):
+    """
+    An instruction group.
+
+    Every instruction must belong to exactly one instruction group. A given
+    target architecture can support instructions from multiple groups, and it
+    does not necessarily support all instructions in a group.
+
+    New instructions are automatically added to the currently open instruction
+    group.
+    """
+
+    # The currently open instruction group.
+    _current = None
+
+    def open(self):
+        """
+        Open this instruction group such that future new instructions are
+        added to this group.
+        """
+        assert InstructionGroup._current is None, (
+                "Can't open {} since {} is already open".format(self, _current))
+        InstructionGroup._current = self
+
+    def close(self):
+        """
+        Close this instruction group. This function should be called before
+        opening another instruction group.
+        """
+        assert InstructionGroup._current is self, (
+                "Can't close {}, the open instuction group is {}".format(self, _current))
+        InstructionGroup._current = None
+
+    def __init__(self, name, doc):
+        self.name = name
+        self.__doc__ = doc
+        self.instructions = []
+        self.open()
+
+    @staticmethod
+    def append(inst):
+        assert InstructionGroup._current, "Open an instruction group before defining instructions."
+        InstructionGroup._current.instructions.append(inst)
+
 class Operand(object):
     """
     An instruction operand.
@@ -202,6 +246,7 @@ class Instruction(object):
         self.__doc__ = doc
         self.ins = self._to_operand_tuple(ins)
         self.outs = self._to_operand_tuple(outs)
+        InstructionGroup.append(self)
 
     @staticmethod
     def _to_operand_tuple(x):
diff --git a/meta/cretonne/base.py b/meta/cretonne/base.py
index a926829d7c..604687829e 100644
--- a/meta/cretonne/base.py
+++ b/meta/cretonne/base.py
@@ -3,10 +3,12 @@ Cretonne base instruction set.
 
 This module defines the basic Cretonne instruction set that all targets support.
 """
-from . import TypeVar, Operand, Instruction
+from . import TypeVar, Operand, Instruction, InstructionGroup
 from types import i8, f32, f64
 from immediates import imm64, ieee32, ieee64, immvector
 
+instructions = InstructionGroup("base", "Shared base instruction set")
+
 Int = TypeVar('Int', 'A scalar or vector integer type')
 iB = TypeVar('iB', 'A scalar integer type')
 TxN = TypeVar('%Tx%N', 'A SIMD vector type')
@@ -321,3 +323,5 @@ popcnt = Instruction('popcnt', r"""
     Count the number of one bits in ``x``.
     """,
     ins=x, outs=a)
+
+instructions.close()