+2003-05-20 Kevin Ryde <user42@zip.com.au>
+ Wolfgang Bangerth <bangerth@dealii.org>
+
+ PR/10355
+ * doc/extend.texi: Put a warning into the documentation
+ of attribute regparm.
+
2003-05-20 Jason Merrill <jason@redhat.com>
* tree.c (expr_last): New fn.
Not all ELF targets support this attribute.
@item regparm (@var{number})
+@cindex @code{regparm} attribute
@cindex functions that are passed arguments in registers on the 386
On the Intel 386, the @code{regparm} attribute causes the compiler to
pass up to @var{number} integer arguments in registers EAX,
variable number of arguments will continue to be passed all of their
arguments on the stack.
+Beware that on some ELF systems this attribute is unsuitable for
+global functions in shared libraries with lazy binding (which is the
+default). Lazy binding will send the first call via resolving code in
+the loader, which might assume EAX, EDX and ECX can be clobbered, as
+per the standard calling conventions. Solaris 8 is affected by this.
+GNU systems with GLIBC 2.1 or higher, and FreeBSD, are believed to be
+safe since the loaders there save all registers. (Lazy binding can be
+disabled with the linker or the loader if desired, to avoid the
+problem.)
+
@item stdcall
@cindex functions that pop the argument stack on the 386
On the Intel 386, the @code{stdcall} attribute causes the compiler to