* doc/rtl.texi: Document value extension requirements for CONST_INT.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@94004 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 19eda0f..74474ec 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2005-01-20  Paul Brook  <paul@codesourcery.com>
+
+       * doc/rtl.texi: Document value extension requirements for CONST_INT.
+
 2005-01-20  Kazu Hirata  <kazu@cs.umass.edu>
 
        * tree-cfg.c (tree_verify_flow_info): Check that a nonlocal

diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index 6068516..9d6b9c2 100644 (file)
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -1286,6 +1286,9 @@ This type of expression represents the integer value @var{i}.  @var{i}
 is customarily accessed with the macro @code{INTVAL} as in
 @code{INTVAL (@var{exp})}, which is equivalent to @code{XWINT (@var{exp}, 0)}.
 
+Constants generated for modes with fewer bits than @code{HOST_WIDE_INT}
+must be sign extended to full width (e.g., with @code{gen_int_mode}).
+
 @findex const0_rtx
 @findex const1_rtx
 @findex const2_rtx