Cygwin: fix or delete a few comments to drop 32 bit references

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/autoload.cc

@@ -35,8 +35,7 @@ bool NO_COPY wsock_started;
  *			 the call.  If this is an odd value then this
  *			 is a flag that non-existence of this function
  *			 is not a fatal error
- *  func addr (8 bytes)  (64 bit ONLY!)
+ *  func addr (8 bytes)  Address of the actual Win32 function.  For the
- *			 Address of the actual Win32 function.  For the
  *			 reason why this is necessary, see the below
  *			 description of the load_state.
  *  func name (n bytes)	 asciz string containing the name of the function
@@ -49,7 +48,7 @@ bool NO_COPY wsock_started;
  *			 gets the process's load address, changes the contents
  *			 here to point to the function address, and changes
  *			 the address argument of the initial jmp call.
- *			 On 64 bit, the jmp is not tweaked directly.  Rather,
+ *			 On x86_64, the jmp is not tweaked directly.  Rather,
  *			 the address of the Win32 function is stored in the
  *			 aforementioned Win32 function address slot and fetched
  *			 there for a jmp *%rax call.  This indirection is

winsup/cygwin/exceptions.cc

@@ -1649,10 +1649,9 @@ _cygtls::call_signal_handler ()
 	    NOTE:
 
 	    We DO NOT change the TEB's stack addresses and we DO NOT move the
-	    _cygtls area to the alternate stack.  This seems to work fine on
+	    _cygtls area to the alternate stack.  This seems to work fine,
-	    32 and 64 bit, but there may be Windows functions not working
+	    but there may be Windows functions not working correctly under
-	    correctly under these circumstances.  Especially 32 bit exception
+	    these circumstances.
-	    handling may be broken.
 
 	    On the other hand, if a Windows function crashed and we're handling
 	    this here, moving the TEB stack addresses may be fatal.
@@ -1752,7 +1751,7 @@ _cygtls::signal_debugger (siginfo_t& si)
 	  if (incyg)
 	    c._CX_instPtr = retaddr ();
 	  memcpy (&context.uc_mcontext, &c, sizeof (CONTEXT));
-	  /* Enough space for 32/64 bit addresses */
+	  /* Enough space for 64 bit addresses */
 	  char sigmsg[2 * sizeof (_CYGWIN_SIGNAL_STRING
 				  " ffffffff ffffffffffffffff")];
 	  __small_sprintf (sigmsg, _CYGWIN_SIGNAL_STRING " %d %y %p",

winsup/cygwin/fhandler.cc

@@ -1504,7 +1504,7 @@ fhandler_dev_null::fhandler_dev_null () :
 ssize_t
 fhandler_dev_null::write (const void *ptr, size_t len)
 {
-  /* Shortcut.  This also fixes a problem with the NUL device on 64 bit:
+  /* Shortcut.  This also fixes a problem with the NUL device on x86_64:
      If you write > 4 GB in a single attempt, the bytes written returned
      from by is numBytes & 0xffffffff. */
   return len;

winsup/cygwin/heap.cc

@@ -29,13 +29,14 @@ static ptrdiff_t page_const;
 static uintptr_t
 eval_start_address ()
 {
-  /* On 64 bit, we choose a fixed address outside the 32 bit area.  The
+  /* We choose a fixed address outside the low 32 bit arena, which is
-     executable starts at 0x1:00400000L, the Cygwin DLL starts at
+     exclusively used by the OS now:
-     0x1:80040000L, other rebased DLLs are located in the region from
+     - The executable starts at 0x1:00400000L
-     0x2:00000000L up to 0x4:00000000L, -auto-image-based DLLs are located
+     - The Cygwin DLL starts at 0x1:80040000L
-     in the region from 0x4:00000000L up to 0x6:00000000L.  Thread stacks
+     - Rebased DLLs are located from 0x2:00000000L up to 0x4:00000000L
-     are located in the region from 0x6:00000000L up to 0x8:00000000L.
+     - auto-image-based DLLs are located from 0x4:00000000L up to 0x6:00000000L
-     So the heap starts at 0x8:00000000L. */
+     - Thread stacks are located from 0x6:00000000L up to 0x8:00000000L.
+     - So the heap starts at 0x8:00000000L. */
   uintptr_t start_address = 0x800000000L;
   return start_address;
 }

winsup/cygwin/mmap.cc

@@ -284,7 +284,6 @@ class mmap_record
     LIST_ENTRY (mmap_record) mr_next;
 
   private:
-    /* 4 byte on 32 bit, 8 byte on 64 bit */
     HANDLE mapping_hdl;
     SIZE_T len;
     caddr_t base_address;

winsup/cygwin/mtinfo.h

@@ -63,9 +63,8 @@ class mtinfo_drive
   lock_state lock;
   TAPE_GET_DRIVE_PARAMETERS _dp;
   TAPE_GET_MEDIA_PARAMETERS _mp;
-  /* sizeof(OVERLAPPED) == 20 on 32 bit, 32 on 64 bit.  A drive is always
+  /* A drive is always opened exclusively by a single process, so instead
-     opened exclusively by a single process, though, so instead of the
+     of the OVERLAPPED structure, we just keep track of the pointer to the
-     OVERLAPPED structure, we just keep track of the pointer to the
      OVERLAPPED structure in the application's fhandler. */
   LPOVERLAPPED ov;
   struct status_flags

winsup/cygwin/syscalls.cc

@@ -4175,10 +4175,6 @@ gethostid (void)
 {
   /* Fetch the globally unique MachineGuid value from
      HKLM/Software/Microsoft/Cryptography and hash it. */
-
-  /* Caution: sizeof long might become > 4 when we go 64 bit, but gethostid
-     is supposed to return a 32 bit value, despite the return type long.
-     That's why hostid is *not* long here. */
   int32_t hostid = 0x40291372; /* Choose a nice start value */
   WCHAR wguid[38];