md.texi (Patterns): Note pattern condition pitfall for unnamed insn.

	* doc/md.texi (Patterns): Note pattern condition pitfall
	for unnamed insn.

From-SVN: r54033

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 23f78c697015fefd36c001fd479ef33d3322bcd4..0b22dbae376620d59350ec0b2ec79e5c819ec5f1 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2002-05-29  Hans-Peter Nilsson  <hp@axis.com>
+
+       * doc/md.texi (Patterns): Note pattern condition pitfall
+       for unnamed insn.
+
 2002-05-29  Jason Thorpe  <thorpej@wasabisystems.com>
 
        * config/sparc/netbsd-elf.c (CPP_SUBTARGET_SPEC64): Remove

diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index c5bfd627fa5f2abb30027bc8939c47dcccb30137..652198df4eb8cdcb8dab988af13eb4efb58a39b6 100644 (file)
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -158,7 +158,9 @@ available in a particular run.
 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