Add addrspacecast instruction.

Patch by Michele Scandale!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194760 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 52 insertions, 3 deletions

diff --git a/docs/LangRef.rst b/docs/LangRef.rst
index 9c033ed481..58bba1ba15 100644
--- a/docs/LangRef.rst
+++ b/docs/LangRef.rst
@@ -2382,6 +2382,10 @@ The following is the syntax for constant expressions:
     Convert a constant, CST, to another TYPE. The constraints of the
     operands are the same as those for the :ref:`bitcast
     instruction <i_bitcast>`.
+``addrspacecast (CST to TYPE)``
+    Convert a constant pointer or constant vector of pointer, CST, to another
+    TYPE in a different address space. The constraints of the operands are the
+    same as those for the :ref:`addrspacecast instruction <i_addrspacecast>`.
 ``getelementptr (CSTPTR, IDX0, IDX1, ...)``, ``getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)``
     Perform the :ref:`getelementptr operation <i_getelementptr>` on
     constants. As with the :ref:`getelementptr <i_getelementptr>`
@@ -5726,9 +5730,9 @@ is always a *no-op cast* because no bits change with this
 conversion. The conversion is done as if the ``value`` had been stored
 to memory and read back as type ``ty2``. Pointer (or vector of
 pointers) types may only be converted to other pointer (or vector of
-pointers) types with this instruction if the pointer sizes are
-equal. To convert pointers to other types, use the :ref:`inttoptr
-<i_inttoptr>` or :ref:`ptrtoint <i_ptrtoint>` instructions first.
+pointers) types with the same address space through this instruction.
+To convert pointers to other types, use the :ref:`inttoptr <i_inttoptr>`
+or :ref:`ptrtoint <i_ptrtoint>` instructions first.
 
 Example:
 """"""""
@@ -5740,6 +5744,51 @@ Example:
       %Z = bitcast <2 x int> %V to i64;        ; yields i64: %V
       %Z = bitcast <2 x i32*> %V to <2 x i64*> ; yields <2 x i64*>
 
+.. _i_addrspacecast:
+
+'``addrspacecast .. to``' Instruction
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      <result> = addrspacecast <pty> <ptrval> to <pty2>       ; yields pty2
+
+Overview:
+"""""""""
+
+The '``addrspacecast``' instruction converts ``ptrval`` from ``pty`` in
+address space ``n`` to type ``pty2`` in address space ``m``.
+
+Arguments:
+""""""""""
+
+The '``addrspacecast``' instruction takes a pointer or vector of pointer value
+to cast and a pointer type to cast it to, which must have a different
+address space.
+
+Semantics:
+""""""""""
+
+The '``addrspacecast``' instruction converts the pointer value
+``ptrval`` to type ``pty2``. It can be a *no-op cast* or a complex
+value modification, depending on the target and the address spaces
+pair. Pointers conversion within the same address space must be
+performed with ``bitcast`` instruction. Note that if the address space
+conversion is legal then both result and operand refer to the same memory
+location.
+
+Example:
+""""""""
+
+.. code-block:: llvm
+
+      %X = addrspacecast i32* %x to addrspace(1) i32*    ; yields addrspace(1) i32*:%x
+      %Y = addrspacecast addrspace(1) <2 x i32>* %y to addrspace(2) i64*    ; yields addrspace(2) i32*:%y
+      %Z = addrspacecast <4 x i32*> %z to <4 x float addrspace(3)*>    ; yelds <4 x float addrspace(3)*>:%z
+
 .. _otherops:
 
 Other Operations