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re PR tree-optimization/33562 (aggregate DSE disabled)

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PR tree-optimization/33562
        PR tree-optimization/61912
        PR tree-optimization/77485
	* doc/invoke.texi: Document new dse-max-object-size param.
	* params.def (PARM_DSE_MAX_OBJECT_SIZE): New PARAM.
	* tree-ssa-dse.c: Include params.h.
	(dse_store_status): New enum.
	(initialize_ao_ref_for_dse): New, partially extracted from
	dse_optimize_stmt.
	(valid_ao_ref_for_dse, normalize_ref): New.
	(setup_live_bytes_from_ref, compute_trims): Likewise.
	(clear_bytes_written_by, maybe_trim_complex_store): Likewise.
	(maybe_trim_partially_dead_store): Likewise.
	(maybe_trim_complex_store): Likewise.
	(dse_classify_store): Renamed from dse_possibly_dead_store_p.
	Track what bytes live from the original store.  Return tri-state
	for dead, partially dead or live.
	(dse_dom_walker): Add constructor, destructor and new private members.
	(delete_dead_call, delete_dead_assignment): New extracted from
	dse_optimize_stmt.
	(dse_optimize_stmt): Make a member of dse_dom_walker.
	Use initialize_ao_ref_for_dse.

        PR tree-optimization/33562
        PR tree-optimization/61912
        PR tree-optimization/77485
	* gcc.dg/tree-ssa/complex-4.c: Remove xfail.
	* gcc.dg/tree-ssa/complex-5.c: Likewise.
	* gcc.dg/tree-ssa/ssa-dse-9.c: Likewise.
	* gcc.dg/tree-ssa/ssa-dse-18.c: New test.
	* gcc.dg/tree-ssa/ssa-dse-19.c: Likewise.
	* gcc.dg/tree-ssa/ssa-dse-20.c: Likewise.
	* gcc.dg/tree-ssa/ssa-dse-21.c: Likewise.

From-SVN: r244442
This commit is contained in:
Jeff Law 2017-01-13 08:42:08 -07:00 committed by Jeff Law
parent 68b36e5903
commit d155c6fef0
12 changed files with 463 additions and 75 deletions
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23
gcc/ChangeLog
View File

@ -1,5 +1,28 @@
2017-01-13 Jeff Law <law@redhat.com>
PR tree-optimization/33562
PR tree-optimization/61912
PR tree-optimization/77485
* doc/invoke.texi: Document new dse-max-object-size param.
* params.def (PARM_DSE_MAX_OBJECT_SIZE): New PARAM.
* tree-ssa-dse.c: Include params.h.
(dse_store_status): New enum.
(initialize_ao_ref_for_dse): New, partially extracted from
dse_optimize_stmt.
(valid_ao_ref_for_dse, normalize_ref): New.
(setup_live_bytes_from_ref, compute_trims): Likewise.
(clear_bytes_written_by, maybe_trim_complex_store): Likewise.
(maybe_trim_partially_dead_store): Likewise.
(maybe_trim_complex_store): Likewise.
(dse_classify_store): Renamed from dse_possibly_dead_store_p.
Track what bytes live from the original store. Return tri-state
for dead, partially dead or live.
(dse_dom_walker): Add constructor, destructor and new private members.
(delete_dead_call, delete_dead_assignment): New extracted from
dse_optimize_stmt.
(dse_optimize_stmt): Make a member of dse_dom_walker.
Use initialize_ao_ref_for_dse.
PR tree-optimization/33562
PR tree-optimization/61912
PR tree-optimization/77485

4
gcc/doc/invoke.texi
View File

@ -9880,6 +9880,10 @@ when adding a new one.
@item avg-loop-niter
Average number of iterations of a loop.
@item dse-max-object-size
Maximum size (in bytes) of objects tracked bytewise by dead store elimination.
Larger values may result in larger compilation times.
@item scev-max-expr-size
Bound on size of expressions used in the scalar evolutions analyzer.
Large expressions slow the analyzer.

5
gcc/params.def
View File

@ -532,6 +532,11 @@ DEFPARAM(PARAM_AVG_LOOP_NITER,
"Average number of iterations of a loop.",
10, 1, 0)
DEFPARAM(PARAM_DSE_MAX_OBJECT_SIZE,
"dse-max-object-size",
"Maximum size (in bytes) of objects tracked bytewise by dead store elimination.",
256, 0, 0)
DEFPARAM(PARAM_SCEV_MAX_EXPR_SIZE,
"scev-max-expr-size",
"Bound on size of expressions used in the scalar evolutions analyzer.",

13
gcc/testsuite/ChangeLog
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@ -1,3 +1,16 @@
2017-01-13 Jeff Law <law@redhat.com>
PR tree-optimization/33562
PR tree-optimization/61912
PR tree-optimization/77485
* gcc.dg/tree-ssa/complex-4.c: Remove xfail.
* gcc.dg/tree-ssa/complex-5.c: Likewise.
* gcc.dg/tree-ssa/ssa-dse-9.c: Likewise.
* gcc.dg/tree-ssa/ssa-dse-18.c: New test.
* gcc.dg/tree-ssa/ssa-dse-19.c: Likewise.
* gcc.dg/tree-ssa/ssa-dse-20.c: Likewise.
* gcc.dg/tree-ssa/ssa-dse-21.c: Likewise.
2017-01-13 Martin Liska <mliska@suse.cz>
PR ipa/79043

2
gcc/testsuite/gcc.dg/tree-ssa/complex-4.c
View File

@ -10,4 +10,4 @@ int f(void)
return g(&t);
}
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" { xfail *-*-* } } } */
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" } } */

2
gcc/testsuite/gcc.dg/tree-ssa/complex-5.c
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@ -8,4 +8,4 @@ int f(void)
__imag__ t = 2;
}
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" { xfail *-*-* } } } */
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" } } */

15
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-18.c Normal file
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@ -0,0 +1,15 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
int g(_Complex int*);
int f(void)
{
_Complex int t = 0;
int i, j;
__imag__ t += 2;
return g(&t);
}
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" } } */
/* { dg-final { scan-tree-dump-times "REALPART_EXPR" 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "IMAGPART_EXPR" 1 "optimized" } } */

15
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-19.c Normal file
View File

@ -0,0 +1,15 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
int g(_Complex int*);
int f(void)
{
_Complex int t = 0;
int i, j;
__real__ t += 2;
return g(&t);
}
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" } } */
/* { dg-final { scan-tree-dump-times "REALPART_EXPR" 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "IMAGPART_EXPR" 1 "optimized" } } */

13
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-20.c Normal file
View File

@ -0,0 +1,13 @@
/* { dg-do compile } */
/* { dg-options "-O1 -fno-tree-dce -fdump-tree-optimized" } */
_Complex int t = 0;
int f(void)
{
t = 0;
__imag__ t = 2;
}
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" } } */
/* { dg-final { scan-tree-dump-times "REALPART_EXPR" 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "IMAGPART_EXPR" 1 "optimized" } } */

12
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-21.c Normal file
View File

@ -0,0 +1,12 @@
/* { dg-do compile } */
/* { dg-options "-O1 -fno-tree-dce -fdump-tree-optimized" } */
_Complex int t = 0;
int f(void)
{
t = 0;
__real__ t = 2;
}
/* { dg-final { scan-tree-dump-times "__complex__" 0 "optimized" } } */
/* { dg-final { scan-tree-dump-times "REALPART_EXPR" 1 "optimized" } } */
/* { dg-final { scan-tree-dump-times "IMAGPART_EXPR" 1 "optimized" } } */

2
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-9.c
View File

@ -11,4 +11,4 @@ foo ()
}
/* We should eliminate the first assignment. */
/* { dg-final { scan-tree-dump-times "VDEF" 2 "dse1" { xfail *-*-* } } } */
/* { dg-final { scan-tree-dump-times "VDEF" 2 "dse1" } } */

432
gcc/tree-ssa-dse.c
View File

@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-dfa.h"
#include "domwalk.h"
#include "tree-cfgcleanup.h"
#include "params.h"
/* This file implements dead store elimination.
@ -68,14 +69,241 @@ along with GCC; see the file COPYING3. If not see
remove their dead edges eventually. */
static bitmap need_eh_cleanup;
/* Return value from dse_classify_store */
enum dse_store_status
{
DSE_STORE_LIVE,
DSE_STORE_MAYBE_PARTIAL_DEAD,
DSE_STORE_DEAD
};
/* STMT is a statement that may write into memory. Analyze it and
initialize WRITE to describe how STMT affects memory.
Return TRUE if the the statement was analyzed, FALSE otherwise.
It is always safe to return FALSE. But typically better optimziation
can be achieved by analyzing more statements. */
static bool
initialize_ao_ref_for_dse (gimple *stmt, ao_ref *write)
{
/* It's advantageous to handle certain mem* functions. */
if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
{
switch (DECL_FUNCTION_CODE (gimple_call_fndecl (stmt)))
{
case BUILT_IN_MEMCPY:
case BUILT_IN_MEMMOVE:
case BUILT_IN_MEMSET:
{
tree size = NULL_TREE;
if (gimple_call_num_args (stmt) == 3)
size = gimple_call_arg (stmt, 2);
tree ptr = gimple_call_arg (stmt, 0);
ao_ref_init_from_ptr_and_size (write, ptr, size);
return true;
}
default:
break;
}
}
else if (is_gimple_assign (stmt))
{
ao_ref_init (write, gimple_assign_lhs (stmt));
return true;
}
return false;
}
/* Given REF from the the alias oracle, return TRUE if it is a valid
memory reference for dead store elimination, false otherwise.
In particular, the reference must have a known base, known maximum
size, start at a byte offset and have a size that is one or more
bytes. */
static bool
valid_ao_ref_for_dse (ao_ref *ref)
{
return (ao_ref_base (ref)
&& ref->max_size != -1
&& (ref->offset % BITS_PER_UNIT) == 0
&& (ref->size % BITS_PER_UNIT) == 0
&& (ref->size != -1));
}
/* Normalize COPY (an ao_ref) relative to REF. Essentially when we are
done COPY will only refer bytes found within REF.
We have already verified that COPY intersects at least one
byte with REF. */
static void
normalize_ref (ao_ref *copy, ao_ref *ref)
{
/* If COPY starts before REF, then reset the beginning of
COPY to match REF and decrease the size of COPY by the
number of bytes removed from COPY. */
if (copy->offset < ref->offset)
{
copy->size -= (ref->offset - copy->offset);
copy->offset = ref->offset;
}
/* If COPY extends beyond REF, chop off its size appropriately. */
if (copy->offset + copy->size > ref->offset + ref->size)
copy->size -= (copy->offset + copy->size - (ref->offset + ref->size));
}
/* Clear any bytes written by STMT from the bitmap LIVE_BYTES. The base
address written by STMT must match the one found in REF, which must
have its base address previously initialized.
This routine must be conservative. If we don't know the offset or
actual size written, assume nothing was written. */
static void
clear_bytes_written_by (sbitmap live_bytes, gimple *stmt, ao_ref *ref)
{
ao_ref write;
if (!initialize_ao_ref_for_dse (stmt, &write))
return;
/* Verify we have the same base memory address, the write
has a known size and overlaps with REF. */
if (valid_ao_ref_for_dse (&write)
&& write.base == ref->base
&& write.size == write.max_size
&& ((write.offset < ref->offset
&& write.offset + write.size > ref->offset)
|| (write.offset >= ref->offset
&& write.offset < ref->offset + ref->size)))
{
normalize_ref (&write, ref);
bitmap_clear_range (live_bytes,
(write.offset - ref->offset) / BITS_PER_UNIT,
write.size / BITS_PER_UNIT);
}
}
/* REF is a memory write. Extract relevant information from it and
initialize the LIVE_BYTES bitmap. If successful, return TRUE.
Otherwise return FALSE. */
static bool
setup_live_bytes_from_ref (ao_ref *ref, sbitmap live_bytes)
{
if (valid_ao_ref_for_dse (ref)
&& (ref->size / BITS_PER_UNIT
<= PARAM_VALUE (PARAM_DSE_MAX_OBJECT_SIZE)))
{
bitmap_clear (live_bytes);
bitmap_set_range (live_bytes, 0, ref->size / BITS_PER_UNIT);
return true;
}
return false;
}
/* Compute the number of elements that we can trim from the head and
tail of ORIG resulting in a bitmap that is a superset of LIVE.
Store the number of elements trimmed from the head and tail in
TRIM_HEAD and TRIM_TAIL. */
static void
compute_trims (ao_ref *ref, sbitmap live, int *trim_head, int *trim_tail)
{
/* We use sbitmaps biased such that ref->offset is bit zero and the bitmap
extends through ref->size. So we know that in the original bitmap
bits 0..ref->size were true. We don't actually need the bitmap, just
the REF to compute the trims. */
/* Now identify how much, if any of the tail we can chop off. */
*trim_tail = 0;
int last_orig = (ref->size / BITS_PER_UNIT) - 1;
int last_live = bitmap_last_set_bit (live);
*trim_tail = (last_orig - last_live) & ~0x1;
/* Identify how much, if any of the head we can chop off. */
int first_orig = 0;
int first_live = bitmap_first_set_bit (live);
*trim_head = (first_live - first_orig) & ~0x1;
}
/* STMT initializes an object from COMPLEX_CST where one or more of the
bytes written may be dead stores. REF is a representation of the
memory written. LIVE is the bitmap of stores that are actually live.
Attempt to rewrite STMT so that only the real or imaginary part of
the object is actually stored. */
static void
maybe_trim_complex_store (ao_ref *ref, sbitmap live, gimple *stmt)
{
int trim_head, trim_tail;
compute_trims (ref, live, &trim_head, &trim_tail);
/* The amount of data trimmed from the head or tail must be at
least half the size of the object to ensure we're trimming
the entire real or imaginary half. By writing things this
way we avoid more O(n) bitmap operations. */
if (trim_tail * 2 >= ref->size / BITS_PER_UNIT)
{
/* TREE_REALPART is live */
tree x = TREE_REALPART (gimple_assign_rhs1 (stmt));
tree y = gimple_assign_lhs (stmt);
y = build1 (REALPART_EXPR, TREE_TYPE (x), y);
gimple_assign_set_lhs (stmt, y);
gimple_assign_set_rhs1 (stmt, x);
}
else if (trim_head * 2 >= ref->size / BITS_PER_UNIT)
{
/* TREE_IMAGPART is live */
tree x = TREE_IMAGPART (gimple_assign_rhs1 (stmt));
tree y = gimple_assign_lhs (stmt);
y = build1 (IMAGPART_EXPR, TREE_TYPE (x), y);
gimple_assign_set_lhs (stmt, y);
gimple_assign_set_rhs1 (stmt, x);
}
/* Other cases indicate parts of both the real and imag subobjects
are live. We do not try to optimize those cases. */
}
/* STMT is a memory write where one or more bytes written are dead
stores. ORIG is the bitmap of bytes stored by STMT. LIVE is the
bitmap of stores that are actually live.
Attempt to rewrite STMT so that it writes fewer memory locations. Right
now we only support trimming at the start or end of the memory region.
It's not clear how much there is to be gained by trimming from the middle
of the region. */
static void
maybe_trim_partially_dead_store (ao_ref *ref, sbitmap live, gimple *stmt)
{
if (is_gimple_assign (stmt))
{
switch (gimple_assign_rhs_code (stmt))
{
case COMPLEX_CST:
maybe_trim_complex_store (ref, live, stmt);
break;
default:
break;
}
}
}
/* A helper of dse_optimize_stmt.
Given a GIMPLE_ASSIGN in STMT that writes to REF, find a candidate
statement *USE_STMT that may prove STMT to be dead.
Return TRUE if the above conditions are met, otherwise FALSE. */
static bool
dse_possible_dead_store_p (ao_ref *ref, gimple *stmt, gimple **use_stmt)
static dse_store_status
dse_classify_store (ao_ref *ref, gimple *stmt, gimple **use_stmt,
bool byte_tracking_enabled, sbitmap live_bytes)
{
gimple *temp;
unsigned cnt = 0;
@ -97,7 +325,7 @@ dse_possible_dead_store_p (ao_ref *ref, gimple *stmt, gimple **use_stmt)
/* Limit stmt walking to be linear in the number of possibly
dead stores. */
if (++cnt > 256)
return false;
return DSE_STORE_LIVE;
if (gimple_code (temp) == GIMPLE_PHI)
defvar = PHI_RESULT (temp);
@ -135,7 +363,7 @@ dse_possible_dead_store_p (ao_ref *ref, gimple *stmt, gimple **use_stmt)
fail = true;
BREAK_FROM_IMM_USE_STMT (ui);
}
/* Do not consider the PHI as use if it dominates the
/* Do not consider the PHI as use if it dominates the
stmt defining the virtual operand we are processing,
we have processed it already in this case. */
if (gimple_bb (defvar_def) != gimple_bb (use_stmt)
@ -164,7 +392,13 @@ dse_possible_dead_store_p (ao_ref *ref, gimple *stmt, gimple **use_stmt)
}
if (fail)
return false;
{
/* STMT might be partially dead and we may be able to reduce
how many memory locations it stores into. */
if (byte_tracking_enabled && !gimple_clobber_p (stmt))
return DSE_STORE_MAYBE_PARTIAL_DEAD;
return DSE_STORE_LIVE;
}
/* If we didn't find any definition this means the store is dead
if it isn't a store to global reachable memory. In this case
@ -172,21 +406,102 @@ dse_possible_dead_store_p (ao_ref *ref, gimple *stmt, gimple **use_stmt)
if (!temp)
{
if (ref_may_alias_global_p (ref))
return false;
return DSE_STORE_LIVE;
temp = stmt;
break;
}
if (byte_tracking_enabled && temp)
clear_bytes_written_by (live_bytes, temp, ref);
}
/* Continue walking until we reach a kill. */
while (!stmt_kills_ref_p (temp, ref));
/* Continue walking until we reach a full kill as a single statement
or there are no more live bytes. */
while (!stmt_kills_ref_p (temp, ref)
&& !(byte_tracking_enabled && bitmap_empty_p (live_bytes)));
*use_stmt = temp;
return true;
return DSE_STORE_DEAD;
}
class dse_dom_walker : public dom_walker
{
public:
dse_dom_walker (cdi_direction direction)
: dom_walker (direction), m_byte_tracking_enabled (false)
{ m_live_bytes = sbitmap_alloc (PARAM_VALUE (PARAM_DSE_MAX_OBJECT_SIZE)); }
~dse_dom_walker () { sbitmap_free (m_live_bytes); }
virtual edge before_dom_children (basic_block);
private:
sbitmap m_live_bytes;
bool m_byte_tracking_enabled;
void dse_optimize_stmt (gimple_stmt_iterator *);
};
/* Delete a dead call STMT, which is mem* call of some kind. */
static void
delete_dead_call (gimple *stmt)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Deleted dead call: ");
print_gimple_stmt (dump_file, stmt, dump_flags, 0);
fprintf (dump_file, "\n");
}
tree lhs = gimple_call_lhs (stmt);
gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
if (lhs)
{
tree ptr = gimple_call_arg (stmt, 0);
gimple *new_stmt = gimple_build_assign (lhs, ptr);
unlink_stmt_vdef (stmt);
if (gsi_replace (&gsi, new_stmt, true))
bitmap_set_bit (need_eh_cleanup, gimple_bb (stmt)->index);
}
else
{
/* Then we need to fix the operand of the consuming stmt. */
unlink_stmt_vdef (stmt);
/* Remove the dead store. */
if (gsi_remove (&gsi, true))
bitmap_set_bit (need_eh_cleanup, gimple_bb (stmt)->index);
release_defs (stmt);
}
}
/* Delete a dead store STMT, which is a gimple assignment. */
static void
delete_dead_assignment (gimple *stmt)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Deleted dead store: ");
print_gimple_stmt (dump_file, stmt, dump_flags, 0);
fprintf (dump_file, "\n");
}
/* Then we need to fix the operand of the consuming stmt. */
unlink_stmt_vdef (stmt);
/* Remove the dead store. */
gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
basic_block bb = gimple_bb (stmt);
if (gsi_remove (&gsi, true))
bitmap_set_bit (need_eh_cleanup, bb->index);
/* And release any SSA_NAMEs set in this statement back to the
SSA_NAME manager. */
release_defs (stmt);
}
/* Attempt to eliminate dead stores in the statement referenced by BSI.
A dead store is a store into a memory location which will later be
@ -198,8 +513,8 @@ dse_possible_dead_store_p (ao_ref *ref, gimple *stmt, gimple **use_stmt)
is used precisely once by a later store to the same location which
post dominates the first store, then the first store is dead. */
static void
dse_optimize_stmt (gimple_stmt_iterator *gsi)
void
dse_dom_walker::dse_optimize_stmt (gimple_stmt_iterator *gsi)
{
gimple *stmt = gsi_stmt (*gsi);
@ -214,6 +529,10 @@ dse_optimize_stmt (gimple_stmt_iterator *gsi)
|| TREE_CODE (gimple_assign_lhs (stmt)) != MEM_REF))
return;
ao_ref ref;
if (!initialize_ao_ref_for_dse (stmt, &ref))
return;
/* We know we have virtual definitions. We can handle assignments and
some builtin calls. */
if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
@ -225,42 +544,26 @@ dse_optimize_stmt (gimple_stmt_iterator *gsi)
case BUILT_IN_MEMSET:
{
gimple *use_stmt;
ao_ref ref;
tree size = NULL_TREE;
if (gimple_call_num_args (stmt) == 3)
size = gimple_call_arg (stmt, 2);
tree ptr = gimple_call_arg (stmt, 0);
ao_ref_init_from_ptr_and_size (&ref, ptr, size);
if (!dse_possible_dead_store_p (&ref, stmt, &use_stmt))
enum dse_store_status store_status;
m_byte_tracking_enabled
= setup_live_bytes_from_ref (&ref, m_live_bytes);
store_status = dse_classify_store (&ref, stmt, &use_stmt,
m_byte_tracking_enabled,
m_live_bytes);
if (store_status == DSE_STORE_LIVE)
return;
if (dump_file && (dump_flags & TDF_DETAILS))
if (store_status == DSE_STORE_MAYBE_PARTIAL_DEAD)
{
fprintf (dump_file, " Deleted dead call: ");
print_gimple_stmt (dump_file, gsi_stmt (*gsi), dump_flags, 0);
fprintf (dump_file, "\n");
maybe_trim_partially_dead_store (&ref, m_live_bytes, stmt);
return;
}
tree lhs = gimple_call_lhs (stmt);
if (lhs)
{
gimple *new_stmt = gimple_build_assign (lhs, ptr);
unlink_stmt_vdef (stmt);
if (gsi_replace (gsi, new_stmt, true))
bitmap_set_bit (need_eh_cleanup, gimple_bb (stmt)->index);
}
else
{
/* Then we need to fix the operand of the consuming stmt. */
unlink_stmt_vdef (stmt);
/* Remove the dead store. */
if (gsi_remove (gsi, true))
bitmap_set_bit (need_eh_cleanup, gimple_bb (stmt)->index);
release_defs (stmt);
}
break;
if (store_status == DSE_STORE_DEAD)
delete_dead_call (stmt);
return;
}
default:
return;
}
@ -276,10 +579,20 @@ dse_optimize_stmt (gimple_stmt_iterator *gsi)
use_stmt = stmt;
else
{
ao_ref ref;
ao_ref_init (&ref, gimple_assign_lhs (stmt));
if (!dse_possible_dead_store_p (&ref, stmt, &use_stmt))
m_byte_tracking_enabled
= setup_live_bytes_from_ref (&ref, m_live_bytes);
enum dse_store_status store_status;
store_status = dse_classify_store (&ref, stmt, &use_stmt,
m_byte_tracking_enabled,
m_live_bytes);
if (store_status == DSE_STORE_LIVE)
return;
if (store_status == DSE_STORE_MAYBE_PARTIAL_DEAD)
{
maybe_trim_partially_dead_store (&ref, m_live_bytes, stmt);
return;
}
}
/* Now we know that use_stmt kills the LHS of stmt. */
@ -290,35 +603,10 @@ dse_optimize_stmt (gimple_stmt_iterator *gsi)
&& !gimple_clobber_p (use_stmt))
return;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " Deleted dead store: ");
print_gimple_stmt (dump_file, gsi_stmt (*gsi), dump_flags, 0);
fprintf (dump_file, "\n");
}
/* Then we need to fix the operand of the consuming stmt. */
unlink_stmt_vdef (stmt);
/* Remove the dead store. */
basic_block bb = gimple_bb (stmt);
if (gsi_remove (gsi, true))
bitmap_set_bit (need_eh_cleanup, bb->index);
/* And release any SSA_NAMEs set in this statement back to the
SSA_NAME manager. */
release_defs (stmt);
delete_dead_assignment (stmt);
}
}
class dse_dom_walker : public dom_walker
{
public:
dse_dom_walker (cdi_direction direction) : dom_walker (direction) {}
virtual edge before_dom_children (basic_block);
};
edge
dse_dom_walker::before_dom_children (basic_block bb)
{
@ -391,7 +679,7 @@ pass_dse::execute (function *fun)
}
BITMAP_FREE (need_eh_cleanup);
/* For now, just wipe the post-dominator information. */
free_dominance_info (CDI_POST_DOMINATORS);
return 0;