From 40da08e0dd91017678b20cb1db2cb529f64d33df Mon Sep 17 00:00:00 2001 From: Jeff Law Date: Fri, 5 Dec 2014 15:19:26 -0700 Subject: [PATCH] md.texi: Note problems using function calls to determine insn lengths and point readers... * doc/md.texi: Note problems using function calls to determine insn lengths and point readers to a potential workaround. From-SVN: r218439 --- gcc/ChangeLog | 5 +++++ gcc/doc/md.texi | 6 ++++++ 2 files changed, 11 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9538737c7d7..0dcf6498e32 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2014-12-05 Jeff Law + + * doc/md.texi: Note problems using function calls to determine + insn lengths and point readers to a potential workaround. + 2014-12-05 Andreas Schwab * combine.c (is_parallel_of_n_reg_sets) diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index b8e5ac522b7..1c70a77399a 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -8345,6 +8345,12 @@ the number of vectors multiplied by the size of each vector. Lengths are measured in addressable storage units (bytes). +Note that it is possible to call functions via the @code{symbol_ref} +mechanism to compute the length of an insn. However, if you use this +mechanism you must provide dummy clauses to express the maximum length +without using the function call. You can an example of this in the +@code{pa} machine description for the @code{call_symref} pattern. + The following macros can be used to refine the length computation: @table @code -- 2.30.2