From e73735563717fa9dfaf10dfa7dfe8242026d6c67 Mon Sep 17 00:00:00 2001 From: Richard Kenner Date: Tue, 1 Feb 1994 18:27:04 -0500 Subject: [PATCH] (make_extraction): Don't make an extraction that has the potential of crossing a boundary. From-SVN: r6462 --- gcc/combine.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/gcc/combine.c b/gcc/combine.c index d682939eb28..25f02970238 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -5120,6 +5120,16 @@ make_extraction (mode, inner, pos, pos_rtx, len, && ! in_compare && ! spans_byte && unsignedp) return 0; + /* Unless we are allowed to span bytes, reject this if we would be + spanning bytes or if the position is not a constant and the length + is not 1. In all other cases, we would only be going outside + out object in cases when an original shift would have been + undefined. */ + if (! spans_byte + && ((pos_rtx == 0 && pos + len > GET_MODE_BITSIZE (is_mode)) + || (pos_rtx != 0 && len != 1))) + return 0; + /* Get the mode to use should INNER be a MEM, the mode for the position, and the mode for the result. */ #ifdef HAVE_insv -- 2.30.2