Support __builtin_memcpy; use it for struct assignment

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1319 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

5 files changed, 93 insertions, 30 deletions

diff --git a/arm/PrintAsm.ml b/arm/PrintAsm.ml
index 77bacc3..bb99bb5 100644
--- a/arm/PrintAsm.ml
+++ b/arm/PrintAsm.ml
@@ -232,6 +232,35 @@ let print_builtin_function oc s =
       fprintf oc "	stfs	%a, [%a, #0]\n" freg FR0 ireg IR0; 2
   | "__builtin_volatile_write_float64" ->
       fprintf oc "	stfd	%a, [%a, #0]\n" freg FR0 ireg IR0; 1
+  (* Block copy *)
+  | "__builtin_memcpy" ->
+      let lbl1 = new_label() in
+      let lbl2 = new_label() in
+      fprintf oc "	cmp	%a, #0\n" ireg IR2;
+      fprintf oc "	beq	%a\n" label lbl1;
+      fprintf oc "%a:	ldrb	%a, [%a], #1\n" label lbl2 ireg IR3 ireg IR1;
+      fprintf oc "	subs	%a, %a, #1\n" ireg IR2 ireg IR2;
+      fprintf oc "	strb	%a, [%a], #1\n" ireg IR3 ireg IR0;
+      fprintf oc "	bne	%a\n" label lbl2;
+      fprintf oc "%a:\n" label lbl1
+(*
+      let lbl = new_label() in
+      fprintf oc "	cmp	%a, #0\n" ireg IR2;
+      fprintf oc "%a:	ldrbne	%a, [%a], #1\n" label lbl ireg IR3 ireg IR1;
+      fprintf oc "	strbne	%a, [%a], #1\n" ireg IR3 ireg IR0;
+      fprintf oc "	subnes	%a, %a, #1\n" ireg IR2 ireg IR2;
+      fprintf oc "	bne	%a\n" label lbl
+*)
+  | "__builtin_memcpy_word" ->
+      let lbl1 = new_label() in
+      let lbl2 = new_label() in
+      fprintf oc "	movs	%a, %a, lsr #2\n" ireg IR2 ireg IR2;
+      fprintf oc "	beq	%a\n" label lbl1;
+      fprintf oc "%a:	ldr	%a, [%a], #4\n" label lbl2 ireg IR3 ireg IR1;
+      fprintf oc "	subs	%a, %a, #1\n" ireg IR2 ireg IR2;
+      fprintf oc "	str	%a, [%a], #4\n" ireg IR3 ireg IR0;
+      fprintf oc "	bne	%a\n" label lbl2;
+      fprintf oc "%a:\n" label lbl1
   (* Catch-all *)
   | s ->
       invalid_arg ("unrecognized builtin function " ^ s)
diff --git a/cfrontend/C2Clight.ml b/cfrontend/C2Clight.ml
index 100c72b..614ad77 100644
--- a/cfrontend/C2Clight.ml
+++ b/cfrontend/C2Clight.ml
@@ -841,6 +841,19 @@ let builtins_generic = {
          (TVoid [], [TPtr(TVoid [], []); TFloat(FDouble, [])], false);
     "__builtin_volatile_write_pointer",
          (TVoid [], [TPtr(TVoid [], []); TPtr(TVoid [], [])], false)
+    (* Block copy *)
+    "__builtin_memcpy",
+         (TPtr(TVoid [], []),
+           [TPtr(TVoid [], []); 
+            TPtr(TVoid [AConst], []); 
+            TInt(Cutil.size_t_ikind, [])],
+          false);
+    "__builtin_memcpy_words",
+         (TPtr(TVoid [], []),
+           [TPtr(TVoid [], []); 
+            TPtr(TVoid [AConst], []); 
+            TInt(Cutil.size_t_ikind, [])],
+          false)
   ]
 }
 
diff --git a/cparser/GCC.ml b/cparser/GCC.ml
index 9f864dc..17b718b 100644
--- a/cparser/GCC.ml
+++ b/cparser/GCC.ml
@@ -124,7 +124,7 @@ let builtins = {
   "__builtin_inf",  (doubleType, [], false);
   "__builtin_inff",  (floatType, [], false);
   "__builtin_infl",  (longDoubleType, [], false);
-  "__builtin_memcpy",  (voidPtrType, [ voidPtrType; voidConstPtrType; uintType ], false);
+  "__builtin_memcpy",  (voidPtrType, [ voidPtrType; voidConstPtrType; sizeType ], false);
   "__builtin_mempcpy",  (voidPtrType, [ voidPtrType; voidConstPtrType; sizeType ], false);
 
   "__builtin_fmod",  (doubleType, [ doubleType ], false);
diff --git a/cparser/StructAssign.ml b/cparser/StructAssign.ml
index f5cecfc..3be917e 100644
--- a/cparser/StructAssign.ml
+++ b/cparser/StructAssign.ml
@@ -19,13 +19,14 @@
    Preserves: simplified code, unblocked code *)
 
 open C
+open Machine
 open Cutil
 open Env
 open Errors
 
 let maxsize = ref 8
 
-let need_memcpy = ref (None: ident option)
+let memcpy_decl = ref (None : ident option)
 
 let memcpy_type =
   TFun(TPtr(TVoid [], []),
@@ -34,14 +35,18 @@ let memcpy_type =
              (Env.fresh_ident "", TInt(size_t_ikind, []))],
        false, [])
 
-let memcpy_ident () =
-  match !need_memcpy with
-  | None ->
-      let id = Env.fresh_ident "memcpy" in
-      need_memcpy := Some id;
-      id
-  | Some id ->
-      id 
+let memcpy_ident env =
+  try fst (Env.lookup_ident env "__builtin_memcpy")
+  with Env.Error _ ->
+  try fst (Env.lookup_ident env "memcpy")
+  with Env.Error _ ->
+  match !memcpy_decl with
+  | Some id -> id
+  | None -> let id = Env.fresh_ident "memcpy" in memcpy_decl := Some id; id
+
+let memcpy_words_ident env =
+  try fst (Env.lookup_ident env "__builtin_memcpy_words")
+  with Env.Error _ -> memcpy_ident env
 
 let transf_assign env loc lhs rhs =
 
@@ -89,7 +94,15 @@ let transf_assign env loc lhs rhs =
   try
     transf lhs rhs
   with Exit ->
-    let memcpy = {edesc = EVar(memcpy_ident()); etyp = memcpy_type} in
+    let by_words =
+      match Cutil.sizeof env lhs.etyp with
+      | Some n -> n mod !config.sizeof_ptr = 0
+      | None -> false in
+    let ident =
+      if by_words
+      then memcpy_word_ident()
+      else memcpy_ident() in
+    let memcpy = {edesc = EVar(ident); etyp = memcpy_type} in
     let e_lhs = {edesc = EUnop(Oaddrof, lhs); etyp = TPtr(lhs.etyp, [])} in
     let e_rhs = {edesc = EUnop(Oaddrof, rhs); etyp = TPtr(rhs.etyp, [])} in
     let e_size = {edesc = ESizeof(lhs.etyp); etyp = TInt(size_t_ikind, [])} in
@@ -131,27 +144,10 @@ let transf_fundef env fd =
   {fd with fd_body = transf_stmt env fd.fd_body}
 
 let program p =
-  need_memcpy := None;
+  memcpy_decl := None;
   let p' = Transform.program ~fundef:transf_fundef p in
-  match !need_memcpy with
+  match !memcpy_decl with
   | None -> p'
   | Some id ->
       {gdesc = Gdecl(Storage_extern, id, memcpy_type, None); gloc = no_loc}
       :: p'
-
-(* Horrible hack *)
-(***
-  let has_memcpy = ref false in
-  need_memcpy := None;
-  List.iter
-    (function {gdesc = Gdecl(_, ({name = "memcpy"} as id), _, _)} ->
-                   need_memcpy := Some id; has_memcpy := true
-            | _ -> ())
-    p;
-  let p' = Transform.program ~fundef:transf_fundef p in
-  match !need_memcpy with
-  | Some id when not !has_memcpy ->
-      {gdesc = Gdecl(Storage_extern, id, memcpy_type, None); gloc = no_loc}
-      :: p'
-  | _ -> p'
-***)
diff --git a/powerpc/PrintAsm.ml b/powerpc/PrintAsm.ml
index f528335..4c89879 100644
--- a/powerpc/PrintAsm.ml
+++ b/powerpc/PrintAsm.ml
@@ -271,6 +271,31 @@ let print_builtin_function oc s =
       fprintf oc "	stfs	%a, 0(%a)\n" freg FPR1 ireg GPR3
   | "__builtin_volatile_write_float64" ->
       fprintf oc "	stfd	%a, 0(%a)\n" freg FPR1 ireg GPR3
+  (* Block copy *)
+  | "__builtin_memcpy" ->
+      let lbl1 = new_label() in
+      let lbl2 = new_label() in
+      fprintf oc "	cmplwi	%a, %a, 0\n" creg CR0 ireg GPR5;
+      fprintf oc "	beq	%a, %a\n" creg CR0 label lbl1;
+      fprintf oc "	mtctr	%a\n" ireg GPR5;
+      fprintf oc "	addi	%a, %a, -1\n" ireg GPR6 ireg GPR3;
+      fprintf oc "	addi	%a, %a, -1\n" ireg GPR4 ireg GPR4;
+      fprintf oc "%a:	lbzu	%a, 1(%a)\n" label lbl2 ireg GPR0 ireg GPR4;
+      fprintf oc "	stbu	%a, 1(%a)\n" ireg GPR0 ireg GPR6;
+      fprintf oc "	bdnz	%a\n" label lbl2;
+      fprintf oc "%a:\n" label lbl1
+  | "__builtin_memcpy_word" ->
+      let lbl1 = new_label() in
+      let lbl2 = new_label() in
+      fprintf oc "	rlwinm.	%a, %a, 30, 2, 31\n" ireg GPR5 ireg GPR5;
+      fprintf oc "	beq	%a, %a\n" creg CR0 label lbl1;
+      fprintf oc "	mtctr	%a\n" ireg GPR5;
+      fprintf oc "	addi	%a, %a, -4\n" ireg GPR6 ireg GPR3;
+      fprintf oc "	addi	%a, %a, -4\n" ireg GPR4 ireg GPR4;
+      fprintf oc "%a:	lwzu	%a, 4(%a)\n" label lbl2 ireg GPR0 ireg GPR4;
+      fprintf oc "	stwu	%a, 4(%a)\n" ireg GPR0 ireg GPR6;
+      fprintf oc "	bdnz	%a\n" label lbl2;
+      fprintf oc "%a:\n" label lbl1
   (* Integer arithmetic *)
   | "__builtin_mulhw" ->
       fprintf oc "	mulhw	%a, %a, %a\n" ireg GPR3 ireg GPR3 ireg GPR4