* switch Xtensa RTL to provide atomic intrinsic helpers instead of Interlocked* functions

rtl/xtensa/xtensa.inc

@@ -127,6 +127,12 @@ Function Sptr : pointer;assembler;
   end;
 
 
+{$ifndef VER3_2}
+{$define FPC_SYSTEM_INTERLOCKED_USE_INTRIN}
+{$endif VER3_2}
+
+
+{$ifdef VER3_2}
 function InterLockedDecrement (var Target: longint) : longint;
   begin
     Result:=Target-1;
@@ -148,14 +154,6 @@ function InterLockedExchange (var Target: longint;Source : longint) : longint;
   end;
 
 
-function InterlockedCompareExchange(var Target: longint; NewValue: longint; Comperand: longint): longint;
-  begin
-    Result:=Target;
-    if Result=Comperand then
-      Target:=NewValue;
-  end;
-
-
 function InterLockedExchangeAdd (var Target: longint;Source : longint) : longint;
   begin
     Result:=Target;
@@ -184,18 +182,37 @@ function InterLockedExchange (var Target: smallint;Source : smallint) : smallint
   end;
 
 
-function InterlockedCompareExchange(var Target: smallint; NewValue: smallint; Comperand: smallint): smallint;
+function InterLockedExchangeAdd (var Target: smallint;Source : smallint) : smallint;
   begin
     Result:=Target;
-    if Result=Comperand then
+    Target:=Result+Source;
+  end;
+{$endif VER3_2}
+
+
+{$ifdef VER3_2}
+function InterlockedCompareExchange(var Target: longint; NewValue: longint; Comperand: longint): longint;
+{$else VER3_2}
+{$define FPC_SYSTEM_HAS_ATOMIC_CMP_XCHG_32}
+function fpc_atomic_cmp_xchg_32 (var Target: longint; NewValue : longint; Comparand: longint): longint; [public,alias:'FPC_ATOMIC_CMP_XCHG_32'];
+{$endif VER3_2}
+  begin
+    Result:=Target;
+    if Result={$ifdef VER3_2}Comperand{$else}Comparand{$endif} then
       Target:=NewValue;
   end;
 
 
-function InterLockedExchangeAdd (var Target: smallint;Source : smallint) : smallint;
+{$ifdef VER3_2}
+function InterlockedCompareExchange(var Target: smallint; NewValue: smallint; Comperand: smallint): smallint;
+{$else VER3_2}
+{$define FPC_SYSTEM_HAS_ATOMIC_CMP_XCHG_16}
+function fpc_atomic_cmp_xchg_16 (var Target: smallint; NewValue : smallint; Comparand: smallint): smallint;
+{$endif VER3_2}
   begin
     Result:=Target;
-    Target:=Result+Source;
+    if Result={$ifdef VER3_2}Comperand{$else}Comparand{$endif} then
+      Target:=NewValue;
   end;