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

arm/CBuiltins.ml

@@ -31,7 +31,16 @@ let builtins = {
       (TInt(IUInt, []), [TInt(IUInt, [])], false);
     (* Float arithmetic *)
     "__builtin_fsqrt",
-      (TFloat(FDouble, []), [TFloat(FDouble, [])], false)
+      (TFloat(FDouble, []), [TFloat(FDouble, [])], false);
+    (* Memory accesses *)
+    "__builtin_read16_reversed",
+      (TInt(IUShort, []), [TPtr(TInt(IUShort, [AConst]), [])], false);
+    "__builtin_read32_reversed",
+      (TInt(IUInt, []), [TPtr(TInt(IUInt, [AConst]), [])], false);
+    "__builtin_write16_reversed",
+      (TVoid [], [TPtr(TInt(IUShort, []), []); TInt(IUShort, [])], false);
+    "__builtin_write32_reversed",
+      (TVoid [], [TPtr(TInt(IUInt, []), []); TInt(IUInt, [])], false);
   ]
 }
 

arm/PrintAsm.ml

@@ -388,6 +388,19 @@ let print_builtin_inline oc name args res =
       end else begin
         fprintf oc "	umull   %a, %a, %a, %a\n" ireg rl ireg rh ireg a ireg b; 1
       end
+  (* Memory accesses *)
+  | "__builtin_read16_reversed", [IR a1], [IR res] ->
+      fprintf oc "	ldrh	%a, [%a, #0]\n" ireg res ireg a1;
+      fprintf oc "	rev16	%a, %a\n" ireg res ireg res; 2
+  | "__builtin_read32_reversed", [IR a1], [IR res] ->
+      fprintf oc "	ldr	%a, [%a, #0]\n" ireg res ireg a1;
+      fprintf oc "	rev	%a, %a\n" ireg res ireg res; 2
+  | "__builtin_write16_reversed", [IR a1; IR a2], _ ->
+      fprintf oc "	rev16	%a, %a\n" ireg IR14 ireg a2;
+      fprintf oc "	strh	%a, [%a, #0]\n" ireg IR14 ireg a1; 2
+  | "__builtin_write32_reversed", [IR a1; IR a2], _ ->
+      fprintf oc "	rev	%a, %a\n" ireg IR14 ireg a2;
+      fprintf oc "	str	%a, [%a, #0]\n" ireg IR14 ireg a1; 2
   (* Catch-all *)
   | _ ->
       invalid_arg ("unrecognized builtin " ^ name)

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 *)
 

cparser/Machine.mli

@@ -16,6 +16,7 @@
 (* Machine-dependent aspects *)
 
 type t = {
+  name: string;
   char_signed: bool;
   sizeof_ptr: int;
   sizeof_short: int;

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)
 

ia32/CBuiltins.ml

@@ -33,6 +33,15 @@ let builtins = {
     "__builtin_fmax",
       (TFloat(FDouble, []), [TFloat(FDouble, []); TFloat(FDouble, [])], false);
     "__builtin_fmin",
-      (TFloat(FDouble, []), [TFloat(FDouble, []); TFloat(FDouble, [])], false)
+      (TFloat(FDouble, []), [TFloat(FDouble, []); TFloat(FDouble, [])], false);
+    (* Memory accesses *)
+    "__builtin_read16_reversed",
+      (TInt(IUShort, []), [TPtr(TInt(IUShort, [AConst]), [])], false);
+    "__builtin_read32_reversed",
+      (TInt(IUInt, []), [TPtr(TInt(IUInt, [AConst]), [])], false);
+    "__builtin_write16_reversed",
+      (TVoid [], [TPtr(TInt(IUShort, []), []); TInt(IUShort, [])], false);
+    "__builtin_write32_reversed",
+      (TVoid [], [TPtr(TInt(IUInt, []), []); TInt(IUInt, [])], false);
   ]
 }

ia32/Machregs.v

@@ -101,6 +101,11 @@ Definition destroyed_by_cond (cond: condition): list mreg :=
 Definition destroyed_by_jumptable: list mreg :=
   nil.
 
+Local Open Scope string_scope.
+
+Definition builtin_write16_reversed := ident_of_string "__builtin_write16_reversed".
+Definition builtin_write32_reversed := ident_of_string "__builtin_write32_reversed".
+
 Definition destroyed_by_builtin (ef: external_function): list mreg :=
   match ef with
   | EF_memcpy sz al =>
@@ -109,6 +114,10 @@ Definition destroyed_by_builtin (ef: external_function): list mreg :=
   | EF_vstore Mfloat32 => X7 :: nil
   | EF_vstore_global (Mint8unsigned|Mint8signed) _ _ => AX :: nil
   | EF_vstore_global Mfloat32 _ _ => X7 :: nil
+  | EF_builtin id sg =>
+      if ident_eq id builtin_write16_reversed
+      || ident_eq id builtin_write32_reversed
+      then CX :: DX :: nil else nil
   | _ => nil
   end.
 
@@ -131,8 +140,6 @@ Definition mregs_for_operation (op: operation): list (option mreg) * option mreg
   | _ => (nil, None)
   end.
 
-Local Open Scope string_scope.
-
 Definition builtin_negl := ident_of_string "__builtin_negl".
 Definition builtin_addl := ident_of_string "__builtin_addl".
 Definition builtin_subl := ident_of_string "__builtin_subl".

ia32/PrintAsm.ml

@@ -442,6 +442,25 @@ let print_builtin_inline oc name args res =
   | "__builtin_mull", [IR a; IR b], [IR rh; IR rl] ->
       assert (a = EAX && b = EDX && rh = EDX && rl = EAX);
       fprintf oc "	mull    %a\n" ireg EDX
+  (* Memory accesses *)
+  | "__builtin_read16_reversed", [IR a1], [IR res] ->
+      fprintf oc "	movzwl	0(%a), %a\n" ireg a1 ireg res;
+      fprintf oc "	rolw	$8, %a\n" ireg16 res
+  | "__builtin_read32_reversed", [IR a1], [IR res] ->
+      fprintf oc "	movl	0(%a), %a\n" ireg a1 ireg res;
+      fprintf oc "	bswap	%a\n" ireg res
+  | "__builtin_write16_reversed", [IR a1; IR a2], _ ->
+      let tmp = if a1 = ECX then EDX else ECX in
+      if a2 <> tmp then
+        fprintf oc "	movl	%a, %a\n" ireg a2 ireg tmp;
+      fprintf oc "	xchg	%a, %a\n" ireg8 tmp high_ireg8 tmp;
+      fprintf oc "	movw	%a, 0(%a)\n" ireg16 tmp ireg a1
+  | "__builtin_write32_reversed", [IR a1; IR a2], _ ->
+      let tmp = if a1 = ECX then EDX else ECX in
+      if a2 <> tmp then
+        fprintf oc "	movl	%a, %a\n" ireg a2 ireg tmp;
+      fprintf oc "	bswap	%a\n" ireg tmp;
+      fprintf oc "	movl	%a, 0(%a)\n" ireg tmp ireg a1
   (* Catch-all *)  
   | _ ->
       invalid_arg ("unrecognized builtin " ^ name)

test/regression/Results/builtins-arm

@@ -2,3 +2,7 @@ bswap(12345678) = 78563412
 bswap16(1234) = 3412
 cntlz(12345678) = 3
 fsqrt(3.141590) = 1.772453
+read_16_rev = 3412
+read_32_rev = efbeadde
+after write_16_rev: 9a78
+after write_32_rev: 78563412

test/regression/Results/builtins-ia32

@@ -3,3 +3,7 @@ bswap16(1234) = 3412
 fsqrt(3.141590) = 1.772453
 fmin(3.141590, 2.718000) = 2.718000
 fmax(3.141590, 2.718000) = 3.141590
+read_16_rev = 3412
+read_32_rev = efbeadde
+after write_16_rev: 9a78
+after write_32_rev: 78563412

test/regression/builtins-arm.c

@@ -14,6 +14,13 @@ int main(int argc, char ** argv)
   printf("cntlz(%x) = %d\n", x, __builtin_cntlz(x));
   printf("fsqrt(%f) = %f\n", a, __builtin_fsqrt(a));
   
+  printf ("read_16_rev = %x\n", __builtin_read16_reversed(&s));
+  printf ("read_32_rev = %x\n", __builtin_read32_reversed(&y));
+  __builtin_write16_reversed(&s, 0x789A);
+  printf ("after write_16_rev: %x\n", s);
+  __builtin_write32_reversed(&y, 0x12345678);
+  printf ("after write_32_rev: %x\n", y);
+
   return 0;
 }
 

test/regression/builtins-ia32.c

@@ -5,6 +5,7 @@
 int main(int argc, char ** argv)
 {
   unsigned int x = 0x12345678;
+  unsigned int y = 0xDEADBEEF;
   double a = 3.14159;
   double b = 2.718;
   unsigned short s = 0x1234;
@@ -16,6 +17,13 @@ int main(int argc, char ** argv)
   printf("fmin(%f, %f) = %f\n", a, b, __builtin_fmin(a, b));
   printf("fmax(%f, %f) = %f\n", a, b, __builtin_fmax(a, b));
 
+  printf ("read_16_rev = %x\n", __builtin_read16_reversed(&s));
+  printf ("read_32_rev = %x\n", __builtin_read32_reversed(&y));
+  __builtin_write16_reversed(&s, 0x789A);
+  printf ("after write_16_rev: %x\n", s);
+  __builtin_write32_reversed(&y, 0x12345678);
+  printf ("after write_32_rev: %x\n", y);
+
   return 0;
 }