From f6943689d2ac302e54087a180cf468b29aa8d938 Mon Sep 17 00:00:00 2001
From: Peter Zotov <whitequark@whitequark.org>
Date: Fri, 6 Feb 2015 13:42:03 +0000
Subject: [PATCH] [OCaml] Add Llvm.build_empty_phi.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228395 91177308-0d34-0410-b5e6-96231b3b80d8
---
 bindings/ocaml/llvm/llvm.ml      | 2 ++
 bindings/ocaml/llvm/llvm.mli     | 6 ++++++
 bindings/ocaml/llvm/llvm_ocaml.c | 9 +++++++++
 test/Bindings/OCaml/core.ml      | 9 +++++++++
 4 files changed, 26 insertions(+)

diff --git a/bindings/ocaml/llvm/llvm.ml b/bindings/ocaml/llvm/llvm.ml
index 042edcba84e..9a3cb1f0de0 100644
--- a/bindings/ocaml/llvm/llvm.ml
+++ b/bindings/ocaml/llvm/llvm.ml
@@ -1300,6 +1300,8 @@ external build_fcmp : Fcmp.t -> llvalue -> llvalue -> string ->
 (*--... Miscellaneous instructions .........................................--*)
 external build_phi : (llvalue * llbasicblock) list -> string -> llbuilder ->
                      llvalue = "llvm_build_phi"
+external build_empty_phi : lltype -> string -> llbuilder -> llvalue
+                         = "llvm_build_empty_phi"
 external build_call : llvalue -> llvalue array -> string -> llbuilder -> llvalue
                     = "llvm_build_call"
 external build_select : llvalue -> llvalue -> llvalue -> string -> llbuilder ->
diff --git a/bindings/ocaml/llvm/llvm.mli b/bindings/ocaml/llvm/llvm.mli
index 8fdddd1895e..dcda02764f5 100644
--- a/bindings/ocaml/llvm/llvm.mli
+++ b/bindings/ocaml/llvm/llvm.mli
@@ -2422,6 +2422,12 @@ val build_fcmp : Fcmp.t -> llvalue -> llvalue -> string ->
 val build_phi : (llvalue * llbasicblock) list -> string -> llbuilder ->
                      llvalue
 
+(** [build_empty_phi ty name b] creates a
+    [%name = phi %ty] instruction at the position specified by
+    the instruction builder [b]. [ty] is the type of the instruction.
+    See the method [llvm::LLVMBuilder::CreatePHI]. *)
+val build_empty_phi : lltype -> string -> llbuilder -> llvalue
+
 (** [build_call fn args name b] creates a
     [%name = call %fn(args...)]
     instruction at the position specified by the instruction builder [b].
diff --git a/bindings/ocaml/llvm/llvm_ocaml.c b/bindings/ocaml/llvm/llvm_ocaml.c
index 1fa4d0f32d0..3889f9276cc 100644
--- a/bindings/ocaml/llvm/llvm_ocaml.c
+++ b/bindings/ocaml/llvm/llvm_ocaml.c
@@ -2191,6 +2191,15 @@ CAMLprim LLVMValueRef llvm_build_phi(value Incoming, value Name, value B) {
   return PhiNode;
 }
 
+/* lltype -> string -> llbuilder -> value */
+CAMLprim LLVMValueRef llvm_build_empty_phi(LLVMTypeRef Type, value Name, value B) {
+  LLVMValueRef PhiNode;
+
+  return LLVMBuildPhi(Builder_val(B), Type, String_val(Name));
+
+  return PhiNode;
+}
+
 /* llvalue -> llvalue array -> string -> llbuilder -> llvalue */
 CAMLprim LLVMValueRef llvm_build_call(LLVMValueRef Fn, value Params,
                                       value Name, value B) {
diff --git a/test/Bindings/OCaml/core.ml b/test/Bindings/OCaml/core.ml
index 0f3daac5bfd..c5e47e79cf2 100644
--- a/test/Bindings/OCaml/core.ml
+++ b/test/Bindings/OCaml/core.ml
@@ -1428,6 +1428,15 @@ let test_builder () =
     add_incoming (p2, b2) phi;
     insist ([(p1, b1); (p2, b2)] = incoming phi);
 
+    (* CHECK: %PhiEmptyNode = phi i8
+     *)
+    let phi_empty = build_empty_phi i8_type "PhiEmptyNode" at_jb in
+    insist ([] = incoming phi_empty);
+
+    (* can't emit an empty phi to bitcode *)
+    add_incoming (const_int i8_type 1, b1) phi_empty;
+    add_incoming (const_int i8_type 2, b2) phi_empty;
+
     ignore (build_unreachable at_jb);
   end
 
-- 
2.34.1