On 01/29/2012 04:09 PM, Eric Botcazou wrote:
As discussed in Bugzilla, this is the patch implementing Paolo's
suggestion of killing REG_EQUAL/REG_EQUIV notes from df_kill_notes. The
code assumes there is at most one such note per insn.
That's wrong though and wreaks havoc during reload, e.g.:
(insn 169 60 62 4 (set (reg:TF 158)
(mem/c:TF (plus:SI (reg/f:SI 101 %sfp)
(const_int -16 [0xfffffffffffffff0])) [3 S16 A64]))
960513-1.c:13 97 {*movtf_insn_sp32}
(expr_list:REG_EQUIV (mem/c:TF (plus:SI (reg/f:SI 101 %sfp)
(const_int -16 [0xfffffffffffffff0])) [3 S16 A64])
(expr_list:REG_EQUAL (mult:TF (reg/v:TF 110 [ d ])
(reg:TF 154))
(nil))))
because the REG_EQUIV note disappears behind reload's back and it isn't
prepared for that. This is the cause of the following regression on SPARC:
FAIL: gcc.c-torture/execute/960513-1.c execution, -Os
As well as:
FAIL: gcc.c-torture/execute/stdarg-2.c execution, -O2
FAIL: gcc.c-torture/execute/stdarg-2.c execution, -O3 -fomit-frame-pointer
FAIL: gcc.c-torture/execute/stdarg-2.c execution, -O3 -g
FAIL: gcc.c-torture/execute/stdarg-2.c execution, -Os
FAIL: gcc.c-torture/execute/stdarg-2.c
execution, -O2 -flto -flto-partition=none
FAIL: gcc.c-torture/execute/stdarg-2.c execution, -O2 -flto
for the exact same reason.
Does this help?
Paolo
2012-01-30 Paolo Bonzini <bonz...@gnu.org>
* df-problems.c (df_kill_notes): Check that the use refers
to the note under examination.
Index: df-problems.c
===================================================================
--- df-problems.c (revision 183693)
+++ df-problems.c (working copy)
@@ -2814,8 +2814,10 @@ df_kill_notes (rtx insn, bitmap live)
{
df_ref use = *use_rec;
if (DF_REF_REGNO (use) > FIRST_PSEUDO_REGISTER
+ && DF_REF_LOC (use)
&& (DF_REF_FLAGS (use) & DF_REF_IN_NOTE)
- && ! bitmap_bit_p (live, DF_REF_REGNO (use)))
+ && ! bitmap_bit_p (live, DF_REF_REGNO (use))
+ && loc_mentioned_in_p (DF_REF_LOC (use), XEXP (link, 0)))
{
deleted = true;
break;