This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Analysis of high priority PR c/2454
- From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- To: roger at eyesopen dot com
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 1 Jul 02 11:27:33 EDT
- Subject: Re: Analysis of high priority PR c/2454
The true issue is that LOAD_EXTEND_OP only applies to paradoxical
subreg's whose arguments are MEMs, i.e. those that really require a
load from memory. Most uses of LOAD_EXTEND_OP check for the MEM, but
a few including those in combine.c's num_sign_bit_copies and
nonzero_bits don't.
But doesn't reload *force* a reload of paradoxical SUBREGs, so that they
*always* come from memory? It *used* to, but perhaps that has changed.
If it still does, something is odd here.