* doc/md.texi (Patterns): Note pattern condition pitfall
for unnamed insn.
From-SVN: r54035
+2002-05-29 Hans-Peter Nilsson <hp@axis.com>
+
+ * doc/md.texi (Patterns): Note pattern condition pitfall
+ for unnamed insn.
+
2002-05-29 Aldy Hernandez <aldyh@redhat.com>
* rs6000.c: (altivec_expand_builtin): Only expand altivec builtins
For nameless patterns, the condition is applied only when matching an
individual insn, and only after the insn has matched the pattern's
recognition template. The insn's operands may be found in the vector
-@code{operands}.
+@code{operands}. For an insn where the condition has once matched, it
+can't be used to control register allocation, for example by excluding
+certain hard registers or hard register combinations.
@item
The @dfn{output template}: a string that says how to output matching