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[PATCH] Fix DSE (PR rtl-optimization/39794, take 2)
On Thu, Apr 23, 2009 at 05:51:05PM +0200, Jakub Jelinek wrote:
> > group->canon_base_mem is a MEM, not an address:
> >
> > gi->base_mem = gen_rtx_MEM (QImode, base);
> > gi->canon_base_mem = canon_rtx (gi->base_mem);
> >
> > so it's wrong too, but differently.
>
> As the only place where canon_base_mem is used is canon_true_dependence
> call, I guess it should be
> gi->canon_base_addr = canon_rtx (base);
> then.
Here is an updated patch, bootstrapped/regtested so far on the trunk
on x86_64-linux and i686-linux, I'll bootstrap/regtest also on
powerpc{,64}-linux on the trunk and on the same arches on 4.4 branch.
Ok for trunk/4.4? For 4.3 sure, it might be eventually desirable there too,
but I don't have immediate plans to do the backport/regtest there.
2009-04-23 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/39794
* alias.c (canon_true_dependence): Add x_addr argument.
* rtl.h (canon_true_dependence): Adjust prototype.
* cse.c (check_dependence): Adjust canon_true_dependence callers.
* cselib.c (cselib_invalidate_mem): Likewise.
* gcse.c (compute_transp): Likewise.
* dse.c (scan_reads_nospill): Likewise.
(record_store, check_mem_read_rtx): Likewise. For non-const or
frame addresses pass base->val_rtx as mem_addr, for
const or frame addresses canon_base_addr of the group plus
optionally offset.
(struct group_info): Rename canon_base_mem to
canon_base_addr.
(get_group_info): Set canon_base_addr to canon_rtx of base, not
canon_rtx of base_mem.
* gcc.dg/pr39794.c: New test.
--- gcc/alias.c.jj 2009-04-22 23:54:25.000000000 +0200
+++ gcc/alias.c 2009-04-23 18:09:28.000000000 +0200
@@ -2287,14 +2287,13 @@ true_dependence (const_rtx mem, enum mac
Variant of true_dependence which assumes MEM has already been
canonicalized (hence we no longer do that here).
The mem_addr argument has been added, since true_dependence computed
- this value prior to canonicalizing. */
+ this value prior to canonicalizing.
+ If x_addr is non-NULL, it is used in preference of XEXP (x, 0). */
int
canon_true_dependence (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr,
- const_rtx x, bool (*varies) (const_rtx, bool))
+ const_rtx x, rtx x_addr, bool (*varies) (const_rtx, bool))
{
- rtx x_addr;
-
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
@@ -2320,7 +2319,8 @@ canon_true_dependence (const_rtx mem, en
if (nonoverlapping_memrefs_p (x, mem))
return 0;
- x_addr = get_addr (XEXP (x, 0));
+ if (! x_addr)
+ x_addr = get_addr (XEXP (x, 0));
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
return 0;
--- gcc/dse.c.jj 2009-04-22 22:20:23.000000000 +0200
+++ gcc/dse.c 2009-04-23 18:20:44.000000000 +0200
@@ -223,7 +223,7 @@ struct store_info
/* This canonized mem. */
rtx mem;
- /* The result of get_addr on mem. */
+ /* Canonized MEM address for use by canon_true_dependence. */
rtx mem_addr;
/* If this is non-zero, it is the alias set of a spill location. */
@@ -476,8 +476,8 @@ struct group_info
do read dependency. */
rtx base_mem;
- /* Canonized version of base_mem, most likely the same thing. */
- rtx canon_base_mem;
+ /* Canonized version of base_mem's address. */
+ rtx canon_base_addr;
/* These two sets of two bitmaps are used to keep track of how many
stores are actually referencing that position from this base. We
@@ -705,7 +705,7 @@ get_group_info (rtx base)
gi->rtx_base = base;
gi->id = rtx_group_next_id++;
gi->base_mem = gen_rtx_MEM (QImode, base);
- gi->canon_base_mem = canon_rtx (gi->base_mem);
+ gi->canon_base_addr = canon_rtx (base);
gi->store1_n = BITMAP_ALLOC (NULL);
gi->store1_p = BITMAP_ALLOC (NULL);
gi->store2_n = BITMAP_ALLOC (NULL);
@@ -1286,7 +1286,7 @@ static rtx get_stored_val (store_info_t,
static int
record_store (rtx body, bb_info_t bb_info)
{
- rtx mem, rhs, const_rhs;
+ rtx mem, rhs, const_rhs, mem_addr;
HOST_WIDE_INT offset = 0;
HOST_WIDE_INT width = 0;
alias_set_type spill_alias_set;
@@ -1456,6 +1456,23 @@ record_store (rtx body, bb_info_t bb_inf
ptr = active_local_stores;
last = NULL;
redundant_reason = NULL;
+ mem = canon_rtx (mem);
+ /* For alias_set != 0 canon_true_dependence should be never called. */
+ if (spill_alias_set)
+ mem_addr = NULL_RTX;
+ else
+ {
+ if (group_id < 0)
+ mem_addr = base->val_rtx;
+ else
+ {
+ group_info_t group
+ = VEC_index (group_info_t, rtx_group_vec, group_id);
+ mem_addr = group->canon_base_addr;
+ }
+ if (offset)
+ mem_addr = plus_constant (mem_addr, offset);
+ }
while (ptr)
{
@@ -1547,13 +1564,13 @@ record_store (rtx body, bb_info_t bb_inf
if (canon_true_dependence (s_info->mem,
GET_MODE (s_info->mem),
s_info->mem_addr,
- mem, rtx_varies_p))
+ mem, mem_addr, rtx_varies_p))
{
s_info->rhs = NULL;
s_info->const_rhs = NULL;
}
}
-
+
/* An insn can be deleted if every position of every one of
its s_infos is zero. */
if (any_positions_needed_p (s_info)
@@ -1580,9 +1597,9 @@ record_store (rtx body, bb_info_t bb_inf
/* Finish filling in the store_info. */
store_info->next = insn_info->store_rec;
insn_info->store_rec = store_info;
- store_info->mem = canon_rtx (mem);
+ store_info->mem = mem;
store_info->alias_set = spill_alias_set;
- store_info->mem_addr = get_addr (XEXP (mem, 0));
+ store_info->mem_addr = mem_addr;
store_info->cse_base = base;
if (width > HOST_BITS_PER_WIDE_INT)
{
@@ -2006,7 +2023,7 @@ replace_read (store_info_t store_info, i
static int
check_mem_read_rtx (rtx *loc, void *data)
{
- rtx mem = *loc;
+ rtx mem = *loc, mem_addr;
bb_info_t bb_info;
insn_info_t insn_info;
HOST_WIDE_INT offset = 0;
@@ -2058,6 +2075,22 @@ check_mem_read_rtx (rtx *loc, void *data
read_info->end = offset + width;
read_info->next = insn_info->read_rec;
insn_info->read_rec = read_info;
+ /* For alias_set != 0 canon_true_dependence should be never called. */
+ if (spill_alias_set)
+ mem_addr = NULL_RTX;
+ else
+ {
+ if (group_id < 0)
+ mem_addr = base->val_rtx;
+ else
+ {
+ group_info_t group
+ = VEC_index (group_info_t, rtx_group_vec, group_id);
+ mem_addr = group->canon_base_addr;
+ }
+ if (offset)
+ mem_addr = plus_constant (mem_addr, offset);
+ }
/* We ignore the clobbers in store_info. The is mildly aggressive,
but there really should not be a clobber followed by a read. */
@@ -2128,7 +2161,7 @@ check_mem_read_rtx (rtx *loc, void *data
= canon_true_dependence (store_info->mem,
GET_MODE (store_info->mem),
store_info->mem_addr,
- mem, rtx_varies_p);
+ mem, mem_addr, rtx_varies_p);
else if (group_id == store_info->group_id)
{
@@ -2139,7 +2172,7 @@ check_mem_read_rtx (rtx *loc, void *data
= canon_true_dependence (store_info->mem,
GET_MODE (store_info->mem),
store_info->mem_addr,
- mem, rtx_varies_p);
+ mem, mem_addr, rtx_varies_p);
/* If this read is just reading back something that we just
stored, rewrite the read. */
@@ -2224,7 +2257,7 @@ check_mem_read_rtx (rtx *loc, void *data
remove = canon_true_dependence (store_info->mem,
GET_MODE (store_info->mem),
store_info->mem_addr,
- mem, rtx_varies_p);
+ mem, mem_addr, rtx_varies_p);
if (remove)
{
@@ -3066,8 +3099,9 @@ scan_reads_nospill (insn_info_t insn_inf
if ((read_info->group_id < 0)
&& canon_true_dependence (group->base_mem,
QImode,
- group->canon_base_mem,
- read_info->mem, rtx_varies_p))
+ group->canon_base_addr,
+ read_info->mem, NULL_RTX,
+ rtx_varies_p))
{
if (kill)
bitmap_ior_into (kill, group->group_kill);
--- gcc/cse.c.jj 2009-04-22 22:20:23.000000000 +0200
+++ gcc/cse.c 2009-04-23 18:09:35.000000000 +0200
@@ -1658,7 +1658,7 @@ check_dependence (rtx *x, void *data)
{
struct check_dependence_data *d = (struct check_dependence_data *) data;
if (*x && MEM_P (*x))
- return canon_true_dependence (d->exp, d->mode, d->addr, *x,
+ return canon_true_dependence (d->exp, d->mode, d->addr, *x, NULL_RTX,
cse_rtx_varies_p);
else
return 0;
--- gcc/rtl.h.jj 2009-04-22 22:20:37.000000000 +0200
+++ gcc/rtl.h 2009-04-23 18:09:35.000000000 +0200
@@ -2290,7 +2290,7 @@ extern rtx canon_rtx (rtx);
extern int true_dependence (const_rtx, enum machine_mode, const_rtx, bool (*)(const_rtx, bool));
extern rtx get_addr (rtx);
extern int canon_true_dependence (const_rtx, enum machine_mode, rtx, const_rtx,
- bool (*)(const_rtx, bool));
+ rtx, bool (*)(const_rtx, bool));
extern int read_dependence (const_rtx, const_rtx);
extern int anti_dependence (const_rtx, const_rtx);
extern int output_dependence (const_rtx, const_rtx);
--- gcc/cselib.c.jj 2009-04-22 22:20:23.000000000 +0200
+++ gcc/cselib.c 2009-04-23 18:09:35.000000000 +0200
@@ -1,6 +1,6 @@
/* Common subexpression elimination library for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008
+ 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
This file is part of GCC.
@@ -1483,7 +1483,7 @@ cselib_invalidate_mem (rtx mem_rtx)
}
if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS)
&& ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr,
- x, cselib_rtx_varies_p))
+ x, NULL_RTX, cselib_rtx_varies_p))
{
has_mem = true;
num_mems++;
--- gcc/gcse.c.jj 2009-04-22 22:20:23.000000000 +0200
+++ gcc/gcse.c 2009-04-23 18:09:35.000000000 +0200
@@ -1,7 +1,7 @@
/* Global common subexpression elimination/Partial redundancy elimination
and global constant/copy propagation for GNU compiler.
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006, 2007, 2008 Free Software Foundation, Inc.
+ 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
This file is part of GCC.
@@ -2512,7 +2512,7 @@ compute_transp (const_rtx x, int indx, s
dest_addr = XEXP (list_entry, 0);
if (canon_true_dependence (dest, GET_MODE (dest), dest_addr,
- x, rtx_addr_varies_p))
+ x, NULL_RTX, rtx_addr_varies_p))
{
if (set_p)
SET_BIT (bmap[bb_index], indx);
--- gcc/testsuite/gcc.dg/pr39794.c.jj 2009-04-23 18:09:35.000000000 +0200
+++ gcc/testsuite/gcc.dg/pr39794.c 2009-04-23 18:21:13.000000000 +0200
@@ -0,0 +1,33 @@
+/* PR rtl-optimization/39794 */
+/* { dg-do run } */
+/* { dg-options "-O2 -funroll-loops" } */
+
+extern void abort ();
+
+void
+foo (int *a, int n)
+{
+ int i;
+ for (i = 0; i < n; i++)
+ {
+ a[i] *= 2;
+ a[i + 1] = a[i - 1] + a[i - 2];
+ }
+}
+
+int a[16];
+int ref[16] = { 0, 1, 4, 2, 10, 12, 24, 44,
+ 72, 136, 232, 416, 736, 1296, 2304, 2032 };
+
+int
+main ()
+{
+ int i;
+ for (i = 0; i < 16; i++)
+ a[i] = i;
+ foo (a + 2, 16 - 3);
+ for (i = 0; i < 16; i++)
+ if (ref[i] != a[i])
+ abort ();
+ return 0;
+}
Jakub