Revert suppression of __builtin_{read,write}_reversed for x86 and ARM,

for compatibility with earlier CompCert versions.
But don't use them in PackedStructs.


git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2216 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

3 files changed, 49 insertions, 33 deletions

diff --git a/cparser/Machine.ml b/cparser/Machine.ml
index 0300582..7696444 100644
--- a/cparser/Machine.ml
+++ b/cparser/Machine.ml
@@ -16,6 +16,7 @@
 (* Machine-dependent aspects *)
 
 type t = {
+  name: string;
   char_signed: bool;
   sizeof_ptr: int;
   sizeof_short: int;
@@ -45,6 +46,7 @@ type t = {
 }
 
 let ilp32ll64 = {
+  name = "ilp32ll64";
   char_signed = false;
   sizeof_ptr = 4;
   sizeof_short = 2;
@@ -74,6 +76,7 @@ let ilp32ll64 = {
 }
 
 let i32lpll64 = {
+  name = "i32lpll64";
   char_signed = false;
   sizeof_ptr = 8;
   sizeof_short = 2;
@@ -103,6 +106,7 @@ let i32lpll64 = {
 }
 
 let il32pll64 = {
+  name = "il32pll64";
   char_signed = false;
   sizeof_ptr = 8;
   sizeof_short = 2;
@@ -133,11 +137,15 @@ let il32pll64 = {
 
 (* Canned configurations for some ABIs *)
 
-let x86_32 = { ilp32ll64 with char_signed = true }
-let x86_64 = { i32lpll64 with char_signed = true }
-let win64 = { il32pll64 with char_signed = true }
-let ppc_32_bigendian = { ilp32ll64 with bigendian = true; bitfields_msb_first = true }
-let arm_littleendian = ilp32ll64
+let x86_32 =
+  { ilp32ll64 with char_signed = true; name = "x86_32" }
+let x86_64 =
+  { i32lpll64 with char_signed = true; name = "x86_64" }
+let win64 =
+  { il32pll64 with char_signed = true; name = "x86_64" }
+let ppc_32_bigendian =
+  { ilp32ll64 with bigendian = true; bitfields_msb_first = true; name = "powerpc" }
+let arm_littleendian = { ilp32ll64 with name = "arm" }
 
 (* Add GCC extensions re: sizeof and alignof *)
 
diff --git a/cparser/Machine.mli b/cparser/Machine.mli
index 3becce3..b621d4c 100644
--- a/cparser/Machine.mli
+++ b/cparser/Machine.mli
@@ -16,6 +16,7 @@
 (* Machine-dependent aspects *)
 
 type t = {
+  name: string;
   char_signed: bool;
   sizeof_ptr: int;
   sizeof_short: int;
diff --git a/cparser/PackedStructs.ml b/cparser/PackedStructs.ml
index dbd5160..ebf210b 100644
--- a/cparser/PackedStructs.ml
+++ b/cparser/PackedStructs.ml
@@ -197,25 +197,31 @@ let arrow_packed_field base pf ty =
 (*  (ty) __builtin_readNN_reversed(&lval)
  or (ty) __builtin_bswapNN(lval) *)
 
+let use_reversed =
+  match !Machine.config.Machine.name with
+  | "powerpc" -> true
+  | _ -> false
+
 let bswap_read loc env lval =
   let ty = lval.etyp in
   let (bsize, aty) = accessor_type loc env ty in
   assert (bsize = 16 || bsize = 32);
   try
-    let (id, fty) =
-      lookup_function loc env (sprintf "__builtin_read%d_reversed" bsize) in
-    let fn = {edesc = EVar id; etyp = fty} in
-    let args = [ecast_opt env (TPtr(aty,[])) (eaddrof lval)] in
-    let call = {edesc = ECall(fn, args); etyp = aty} in
-    ecast_opt env ty call
-  with Env.Error _ ->
-  try
-    let (id, fty) =
-      lookup_function loc env (sprintf "__builtin_bswap%d" bsize) in
-    let fn = {edesc = EVar id; etyp = fty} in
-    let args = [ecast_opt env aty lval] in
-    let call = {edesc = ECall(fn, args); etyp = aty} in
-    ecast_opt env ty call
+    if use_reversed then begin
+      let (id, fty) =
+        lookup_function loc env (sprintf "__builtin_read%d_reversed" bsize) in
+      let fn = {edesc = EVar id; etyp = fty} in
+      let args = [ecast_opt env (TPtr(aty,[])) (eaddrof lval)] in
+      let call = {edesc = ECall(fn, args); etyp = aty} in
+      ecast_opt env ty call
+    end else begin
+      let (id, fty) =
+        lookup_function loc env (sprintf "__builtin_bswap%d" bsize) in
+      let fn = {edesc = EVar id; etyp = fty} in
+      let args = [ecast_opt env aty lval] in
+      let call = {edesc = ECall(fn, args); etyp = aty} in
+      ecast_opt env ty call
+    end
   with Env.Error msg ->
     fatal_error "%a: Error: %s" formatloc loc (Env.error_message msg)
 
@@ -228,20 +234,21 @@ let bswap_write loc env lhs rhs =
     accessor_type loc env ty in
   assert (bsize = 16 || bsize = 32);
   try
-    let (id, fty) =
-      lookup_function loc env (sprintf "__builtin_write%d_reversed" bsize) in
-    let fn = {edesc = EVar id; etyp = fty} in
-    let args = [ecast_opt env (TPtr(aty,[])) (eaddrof lhs); 
-                ecast_opt env aty rhs] in
-    {edesc = ECall(fn, args); etyp = TVoid[]}
-  with Env.Error _ ->
-  try
-    let (id, fty) =
-      lookup_function loc env (sprintf "__builtin_bswap%d" bsize) in
-    let fn = {edesc = EVar id; etyp = fty} in
-    let args = [ecast_opt env aty rhs] in
-    let call = {edesc = ECall(fn, args); etyp = aty} in
-    eassign lhs (ecast_opt env ty call)
+    if use_reversed then begin
+      let (id, fty) =
+        lookup_function loc env (sprintf "__builtin_write%d_reversed" bsize) in
+      let fn = {edesc = EVar id; etyp = fty} in
+      let args = [ecast_opt env (TPtr(aty,[])) (eaddrof lhs); 
+                  ecast_opt env aty rhs] in
+      {edesc = ECall(fn, args); etyp = TVoid[]}
+    end else begin
+      let (id, fty) =
+        lookup_function loc env (sprintf "__builtin_bswap%d" bsize) in
+      let fn = {edesc = EVar id; etyp = fty} in
+      let args = [ecast_opt env aty rhs] in
+      let call = {edesc = ECall(fn, args); etyp = aty} in
+      eassign lhs (ecast_opt env ty call)
+    end
   with Env.Error msg ->
     fatal_error "%a: Error: %s" formatloc loc (Env.error_message msg)