| Message ID | 4F16F628.8030002@ispras.ru |
|---|---|
| State | New |
| Headers | show |
On 01/18/2012 05:41 PM, Andrey Belevantsev wrote: > Hello, > > 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. Bootstrapped and > tested on x86-64, ok for trunk? > > Andrey > > gcc: > 2012-01-18 Andrey Belevantsev <abel@ispras.ru> > > PR rtl-optimization/51505 > * df-problems.c (df_kill_notes): New parameter live. Update comment. > Remove REG_EQUAL/REG_EQUIV notes referring to dead registers. > (df_note_bb_compute): Update the call to df_kill_notes. > > testsuite: > 2012-01-18 Andrey Belevantsev <abel@ispras.ru> > > PR rtl-optimization/51505 > * gcc.dg/pr51505.c: New test. Ok, thanks for working on this. Paolo
On 18.01.2012 21:28, Paolo Bonzini wrote: > On 01/18/2012 05:41 PM, Andrey Belevantsev wrote: > Ok, thanks for working on this. Installed, do you want this for 4.6/4.5? Andrey
On Thu, Jan 19, 2012 at 11:32:41AM +0400, Andrey Belevantsev wrote: > On 18.01.2012 21:28, Paolo Bonzini wrote: > >On 01/18/2012 05:41 PM, Andrey Belevantsev wrote: > >Ok, thanks for working on this. > Installed, do you want this for 4.6/4.5? If yes, please give it at least a couple of weeks on the trunk. Jakub
On 01/19/2012 08:34 AM, Jakub Jelinek wrote: >>> > >Ok, thanks for working on this. >> > Installed, do you want this for 4.6/4.5? > If yes, please give it at least a couple of weeks on the trunk. It's fine by me but yes, let's give it time to bake. Paolo
> 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 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.
diff --git a/gcc/df-problems.c b/gcc/df-problems.c index 8928454..f9b0bc1 100644 --- a/gcc/df-problems.c +++ b/gcc/df-problems.c @@ -2748,10 +2748,12 @@ df_ignore_stack_reg (int regno ATTRIBUTE_UNUSED) /* Remove all of the REG_DEAD or REG_UNUSED notes from INSN and add - them to OLD_DEAD_NOTES and OLD_UNUSED_NOTES. */ + them to OLD_DEAD_NOTES and OLD_UNUSED_NOTES. Remove also + REG_EQUAL/REG_EQUIV notes referring to dead pseudos using LIVE + as the bitmap of currently live registers. */ static void -df_kill_notes (rtx insn) +df_kill_notes (rtx insn, bitmap live) { rtx *pprev = ®_NOTES (insn); rtx link = *pprev; @@ -2798,6 +2800,45 @@ df_kill_notes (rtx insn) } break; + case REG_EQUAL: + case REG_EQUIV: + { + /* Remove the notes that refer to dead registers. As we have at most + one REG_EQUAL/EQUIV note, all of EQ_USES will refer to this note + so we need to purge the complete EQ_USES vector when removing + the note using df_notes_rescan. */ + df_ref *use_rec; + bool deleted = false; + + for (use_rec = DF_INSN_EQ_USES (insn); *use_rec; use_rec++) + { + df_ref use = *use_rec; + if (DF_REF_REGNO (use) > FIRST_PSEUDO_REGISTER + && (DF_REF_FLAGS (use) & DF_REF_IN_NOTE) + && ! bitmap_bit_p (live, DF_REF_REGNO (use))) + { + deleted = true; + break; + } + } + if (deleted) + { + rtx next; +#ifdef REG_DEAD_DEBUGGING + df_print_note ("deleting: ", insn, link); +#endif + next = XEXP (link, 1); + free_EXPR_LIST_node (link); + *pprev = link = next; + df_notes_rescan (insn); + } + else + { + pprev = &XEXP (link, 1); + link = *pprev; + } + break; + } default: pprev = &XEXP (link, 1); link = *pprev; @@ -3299,7 +3340,7 @@ df_note_bb_compute (unsigned int bb_index, debug_insn = DEBUG_INSN_P (insn); bitmap_clear (do_not_gen); - df_kill_notes (insn); + df_kill_notes (insn, live); /* Process the defs. */ if (CALL_P (insn)) diff --git a/gcc/testsuite/gcc.dg/pr51505.c b/gcc/testsuite/gcc.dg/pr51505.c new file mode 100644 index 0000000..dbcd322 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr51505.c @@ -0,0 +1,19 @@ +/* PR rtl-optimization/51505 */ +/* { dg-do compile } */ +/* { dg-options "-O --param max-cse-insns=1" } */ +struct S +{ +char a[256]; +}; + +int bar(struct S, char[16]); + +void foo () +{ + struct S u, s1, s2; + char e[256]; + char i; + e[i] = ~s1.a[i] & s2.a[i]; + if (bar(u, e)) + __builtin_abort (); +}