2014-07-04 Tom de Vries <tom@codesourcery.com>
* doc/md.texi (@subsection Constraint Modifier Characters): Clarify
combination of earlyclobber and read/write modifiers.
@@ -1582,7 +1582,10 @@ alternatives of this form often allows GCC to produce better code
when only some of the inputs can be affected by the earlyclobber.
See, for example, the @samp{mulsi3} insn of the ARM@.
-@samp{&} does not obviate the need to write @samp{=}.
+Furthermore, if the @dfn{earlyclobber} operand is also read/write operand, then
+that operand is modified only after it's used.
+
+@samp{&} does not obviate the need to write @samp{=} or @samp{+}.
@cindex @samp{%} in constraint
@item %
--
1.9.1