Add insturction semantics. Add semantics for vsplit,vconcat,iadd. Add initial tests

lib/cretonne/meta/base/semantics.py

@@ -0,0 +1,57 @@
+from __future__ import absolute_import
+from semantics.primitives import prim_to_bv, prim_from_bv, bvsplit, bvconcat,\
+    bvadd
+from .instructions import vsplit, vconcat, iadd
+from cdsl.xform import XForm, Rtl
+from cdsl.ast import Var
+from cdsl.typevar import TypeSet
+from cdsl.ti import InTypeset
+import semantics.types # noqa
+
+x = Var('x')
+y = Var('y')
+a = Var('a')
+xhi = Var('xhi')
+yhi = Var('yhi')
+ahi = Var('ahi')
+xlo = Var('xlo')
+ylo = Var('ylo')
+alo = Var('alo')
+lo = Var('lo')
+hi = Var('hi')
+bvx = Var('bvx')
+bvy = Var('bvy')
+bva = Var('bva')
+bvlo = Var('bvlo')
+bvhi = Var('bvhi')
+
+ScalarTS = TypeSet(lanes=(1, 1), ints=True, floats=True, bools=True)
+
+vsplit.set_semantics(
+    XForm(Rtl((lo, hi) << vsplit(x)),
+          Rtl(bvx << prim_to_bv(x),
+              (bvlo, bvhi) << bvsplit(bvx),
+              lo << prim_from_bv(bvlo),
+              hi << prim_from_bv(bvhi))))
+
+vconcat.set_semantics(
+    XForm(Rtl(x << vconcat(lo, hi)),
+          Rtl(bvlo << prim_to_bv(lo),
+              bvhi << prim_to_bv(hi),
+              bvx << bvconcat(bvlo, bvhi),
+              x << prim_from_bv(bvx))))
+
+iadd.set_semantics([
+     XForm(Rtl(a << iadd(x, y)),
+           Rtl(bvx << prim_to_bv(x),
+               bvy << prim_to_bv(y),
+               bva << bvadd(bvx, bvy),
+               a << prim_from_bv(bva)),
+           constraints=[InTypeset(x.get_typevar(), ScalarTS)]),
+     XForm(Rtl(a << iadd(x, y)),
+           Rtl((xlo, xhi) << vsplit(x),
+               (ylo, yhi) << vsplit(y),
+               alo << iadd(xlo, ylo),
+               ahi << iadd(xhi, yhi),
+               a << vconcat(alo, ahi)))
+])