| Message ID | 20130128141408.GG4385@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
On 01/28/2013 07:14 AM, Jakub Jelinek wrote: > Hi! > > We ICE on the following testcase when using cselib, because > cselib_lookup* is never called on the PREFETCH argument, and > add_insn_mem_dependence calls cselib_subst_to_values on it, which > assumes cselib_lookup* already happened on it earlier. > For MEMs sched_analyze_2 calls cselib_lookup_from_insn, but for PREFETCHes > it didn't. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, > ok for trunk? > > 2013-01-28 Jakub Jelinek <jakub@redhat.com> > > PR rtl-optimization/56117 > * sched-deps.c (sched_analyze_2) <case PREFETCH>: For use_cselib > call cselib_lookup_from_insn on the MEM before calling > add_insn_mem_dependence. > > * gcc.dg/pr56117.c: New test. I'm assuming that we don't need the shallow_copy_rtx call and related code because in the PREFETCH case we generate a new MEM and the underlying address can be safely shared. Right? If that's true, OK. jeff
On Mon, Jan 28, 2013 at 09:39:00AM -0700, Jeff Law wrote: > I'm assuming that we don't need the shallow_copy_rtx call and > related code because in the PREFETCH case we generate a new MEM and > the underlying address can be safely shared. Right? AFAIK cselib_lookup* never modifies the rtx it is passed, shallow_copy_rtx in the MEM case is for: t = shallow_copy_rtx (dest); cselib_lookup_from_insn (XEXP (t, 0), address_mode, 1, GET_MODE (t), insn); XEXP (t, 0) = cselib_subst_to_values_from_insn (XEXP (t, 0), GET_MODE (t), insn); where we modify XEXP (t, 0) in the last assignment and don't want to change XEXP (dest, 0). Jakub
--- gcc/sched-deps.c.jj 2013-01-16 19:58:42.000000000 +0100 +++ gcc/sched-deps.c 2013-01-28 09:43:33.248657691 +0100 @@ -2720,8 +2720,12 @@ sched_analyze_2 (struct deps_desc *deps, prefetch has only the start address but it is better to have something than nothing. */ if (!deps->readonly) - add_insn_mem_dependence (deps, true, insn, - gen_rtx_MEM (Pmode, XEXP (PATTERN (insn), 0))); + { + rtx x = gen_rtx_MEM (Pmode, XEXP (PATTERN (insn), 0)); + if (sched_deps_info->use_cselib) + cselib_lookup_from_insn (x, Pmode, true, VOIDmode, insn); + add_insn_mem_dependence (deps, true, insn, x); + } break; case UNSPEC_VOLATILE: --- gcc/testsuite/gcc.dg/pr56117.c.jj 2013-01-28 09:47:21.244381559 +0100 +++ gcc/testsuite/gcc.dg/pr56117.c 2013-01-28 09:46:31.000000000 +0100 @@ -0,0 +1,9 @@ +/* PR rtl-optimization/56117 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fsched2-use-superblocks" } */ + +void +foo (void *p) +{ + __builtin_prefetch (p); +}