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re PR tree-optimization/51938 (missed optimization: 2 comparisons)

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2012-08-06 Marc Glisse <marc.glisse@inria.fr>

gcc/
	PR tree-optimization/51938
	PR tree-optimization/52005
	* tree-ssa-ifcombine.c (ifcombine_ifandif): New parameters for
	inverted conditions.
	(ifcombine_iforif): Remove, merge code into ifcombine_ifandif.
	(tree_ssa_ifcombine_bb): Update calls to the above. Detect !a&&b
	and !a||b patterns.

gcc/testsuite/
	PR tree-optimization/51938
	PR tree-optimization/52005
	* gcc.dg/tree-ssa/ssa-ifcombine-8.c: New testcase.
	* gcc.dg/tree-ssa/ssa-ifcombine-9.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-10.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-11.c: Likewise.

From-SVN: r190184
This commit is contained in:
Marc Glisse 2012-08-06 18:38:48 +02:00 committed by Marc Glisse
parent 61b6d4cdee
commit 777d77b37a
7 changed files with 193 additions and 84 deletions
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10
gcc/ChangeLog
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@ -1,3 +1,13 @@
2012-08-06 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/51938
PR tree-optimization/52005
* tree-ssa-ifcombine.c (ifcombine_ifandif): New parameters for
inverted conditions.
(ifcombine_iforif): Remove, merge code into ifcombine_ifandif.
(tree_ssa_ifcombine_bb): Update calls to the above. Detect !a&&b
and !a||b patterns.
2012-08-06 Olivier Hainque <hainque@adacore.com>
* tree-emutls.c (new_emutls_decl): When a var_section is requested by

9
gcc/testsuite/ChangeLog
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@ -1,3 +1,12 @@
2012-08-06 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/51938
PR tree-optimization/52005
* gcc.dg/tree-ssa/ssa-ifcombine-8.c: New testcase.
* gcc.dg/tree-ssa/ssa-ifcombine-9.c: Likewise.
* gcc.dg/tree-ssa/ssa-ifcombine-10.c: Likewise.
* gcc.dg/tree-ssa/ssa-ifcombine-11.c: Likewise.
2012-08-06 Dodji Seketeli <dodji@redhat.com>
Avoid crashing on erroneous static_assert usage

20
gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-10.c Normal file
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@ -0,0 +1,20 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
/* Testcase for PR31657. */
int f(int x, int a, int b)
{
int t = 0;
int c = 1 << a;
if (!(x & 1))
t = 0;
else
if (x & (1 << 2))
t = 3;
else
t = 0;
return t;
}
/* { dg-final { scan-tree-dump "& 5" "optimized" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */

21
gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-11.c Normal file
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@ -0,0 +1,21 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-optimized" } */
/* Testcase for PR31657. */
int g(void);
int f(int x, int a, int b)
{
int t = 0;
int c = 1 << a;
if (!(x & 1))
t = 0;
else
if (x & (1 << 2))
t = g();
else
t = 0;
return t;
}
/* { dg-final { scan-tree-dump "& 5" "optimized" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */

25
gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-8.c Normal file
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@ -0,0 +1,25 @@
/* { dg-do compile } */
/* { dg-options "-O -fno-trapping-math -fdump-tree-ifcombine" } */
double test1 (double i, double j)
{
if (i >= j)
if (i <= j)
goto plif;
else
goto plouf;
else
goto plif;
plif:
return 0;
plouf:
return -1;
}
/* The above should be optimized to a i > j test by ifcombine.
The transformation would also be legal with -ftrapping-math.
Instead we get u<=, which is acceptable with -fno-trapping-math. */
/* { dg-final { scan-tree-dump " u<= " "ifcombine" } } */
/* { dg-final { cleanup-tree-dump "ifcombine" } } */

22
gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-9.c Normal file
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@ -0,0 +1,22 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fno-trapping-math -fdump-tree-ifcombine" } */
void f ();
enum Sign { NEG=-1, ZERO, POS };
static inline enum Sign sign (double x)
{
if (x > 0) return POS;
if (x < 0) return NEG;
return ZERO;
}
void g (double x)
{
if (sign (x) == NEG) f();
}
/* The above should be optimized to x < 0 by ifcombine.
The transformation would also be legal with -ftrapping-math. */
/* { dg-final { scan-tree-dump "optimizing.* < " "ifcombine" } } */
/* { dg-final { cleanup-tree-dump "ifcombine" } } */

170
gcc/tree-ssa-ifcombine.c
View File

@ -166,12 +166,12 @@ get_name_for_bit_test (tree candidate)
Returns true if the pattern matched, false otherwise. */
static bool
recognize_single_bit_test (gimple cond, tree *name, tree *bit)
recognize_single_bit_test (gimple cond, tree *name, tree *bit, bool inv)
{
gimple stmt;
/* Get at the definition of the result of the bit test. */
if (gimple_cond_code (cond) != NE_EXPR
if (gimple_cond_code (cond) != (inv ? EQ_EXPR : NE_EXPR)
|| TREE_CODE (gimple_cond_lhs (cond)) != SSA_NAME
|| !integer_zerop (gimple_cond_rhs (cond)))
return false;
@ -274,12 +274,12 @@ recognize_single_bit_test (gimple cond, tree *name, tree *bit)
Returns true if the pattern matched, false otherwise. */
static bool
recognize_bits_test (gimple cond, tree *name, tree *bits)
recognize_bits_test (gimple cond, tree *name, tree *bits, bool inv)
{
gimple stmt;
/* Get at the definition of the result of the bit test. */
if (gimple_cond_code (cond) != NE_EXPR
if (gimple_cond_code (cond) != (inv ? EQ_EXPR : NE_EXPR)
|| TREE_CODE (gimple_cond_lhs (cond)) != SSA_NAME
|| !integer_zerop (gimple_cond_rhs (cond)))
return false;
@ -296,14 +296,17 @@ recognize_bits_test (gimple cond, tree *name, tree *bits)
/* If-convert on a and pattern with a common else block. The inner
if is specified by its INNER_COND_BB, the outer by OUTER_COND_BB.
inner_inv, outer_inv and result_inv indicate whether the conditions
are inverted.
Returns true if the edges to the common else basic-block were merged. */
static bool
ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
ifcombine_ifandif (basic_block inner_cond_bb, bool inner_inv,
basic_block outer_cond_bb, bool outer_inv, bool result_inv)
{
gimple_stmt_iterator gsi;
gimple inner_cond, outer_cond;
tree name1, name2, bit1, bit2;
tree name1, name2, bit1, bit2, bits1, bits2;
inner_cond = last_stmt (inner_cond_bb);
if (!inner_cond
@ -319,8 +322,8 @@ ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
that case remove the outer test, merging both else edges,
and change the inner one to test for
name & (bit1 | bit2) == (bit1 | bit2). */
if (recognize_single_bit_test (inner_cond, &name1, &bit1)
&& recognize_single_bit_test (outer_cond, &name2, &bit2)
if (recognize_single_bit_test (inner_cond, &name1, &bit1, inner_inv)
&& recognize_single_bit_test (outer_cond, &name2, &bit2, outer_inv)
&& name1 == name2)
{
tree t, t2;
@ -337,7 +340,8 @@ ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
t2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
t2 = force_gimple_operand_gsi (&gsi, t2, true, NULL_TREE,
true, GSI_SAME_STMT);
t = fold_build2 (EQ_EXPR, boolean_type_node, t2, t);
t = fold_build2 (result_inv ? NE_EXPR : EQ_EXPR,
boolean_type_node, t2, t);
t = canonicalize_cond_expr_cond (t);
if (!t)
return false;
@ -345,7 +349,8 @@ ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond, boolean_true_node);
gimple_cond_set_condition_from_tree (outer_cond,
outer_inv ? boolean_false_node : boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
@ -362,68 +367,11 @@ ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
return true;
}
/* See if we have two comparisons that we can merge into one. */
else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
&& TREE_CODE_CLASS (gimple_cond_code (outer_cond)) == tcc_comparison)
{
tree t;
if (!(t = maybe_fold_and_comparisons (gimple_cond_code (inner_cond),
gimple_cond_lhs (inner_cond),
gimple_cond_rhs (inner_cond),
gimple_cond_code (outer_cond),
gimple_cond_lhs (outer_cond),
gimple_cond_rhs (outer_cond))))
return false;
t = canonicalize_cond_expr_cond (t);
if (!t)
return false;
gimple_cond_set_condition_from_tree (inner_cond, t);
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond, boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
{
fprintf (dump_file, "optimizing two comparisons to ");
print_generic_expr (dump_file, t, 0);
fprintf (dump_file, "\n");
}
return true;
}
return false;
}
/* If-convert on a or pattern with a common then block. The inner
if is specified by its INNER_COND_BB, the outer by OUTER_COND_BB.
Returns true, if the edges leading to the common then basic-block
were merged. */
static bool
ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
{
gimple inner_cond, outer_cond;
tree name1, name2, bits1, bits2;
inner_cond = last_stmt (inner_cond_bb);
if (!inner_cond
|| gimple_code (inner_cond) != GIMPLE_COND)
return false;
outer_cond = last_stmt (outer_cond_bb);
if (!outer_cond
|| gimple_code (outer_cond) != GIMPLE_COND)
return false;
/* See if we have two bit tests of the same name in both tests.
In that case remove the outer test and change the inner one to
test for name & (bits1 | bits2) != 0. */
if (recognize_bits_test (inner_cond, &name1, &bits1)
&& recognize_bits_test (outer_cond, &name2, &bits2))
else if (recognize_bits_test (inner_cond, &name1, &bits1, !inner_inv)
&& recognize_bits_test (outer_cond, &name2, &bits2, !outer_inv))
{
gimple_stmt_iterator gsi;
tree t;
@ -482,7 +430,7 @@ ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
true, GSI_SAME_STMT);
t = fold_build2 (NE_EXPR, boolean_type_node, t,
t = fold_build2 (result_inv ? NE_EXPR : EQ_EXPR, boolean_type_node, t,
build_int_cst (TREE_TYPE (t), 0));
t = canonicalize_cond_expr_cond (t);
if (!t)
@ -491,7 +439,8 @@ ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond, boolean_false_node);
gimple_cond_set_condition_from_tree (outer_cond,
outer_inv ? boolean_false_node : boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
@ -508,21 +457,36 @@ ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
return true;
}
/* See if we have two comparisons that we can merge into one.
This happens for C++ operator overloading where for example
GE_EXPR is implemented as GT_EXPR || EQ_EXPR. */
else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
/* See if we have two comparisons that we can merge into one. */
else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
&& TREE_CODE_CLASS (gimple_cond_code (outer_cond)) == tcc_comparison)
{
tree t;
enum tree_code inner_cond_code = gimple_cond_code (inner_cond);
enum tree_code outer_cond_code = gimple_cond_code (outer_cond);
if (!(t = maybe_fold_or_comparisons (gimple_cond_code (inner_cond),
gimple_cond_lhs (inner_cond),
gimple_cond_rhs (inner_cond),
gimple_cond_code (outer_cond),
gimple_cond_lhs (outer_cond),
gimple_cond_rhs (outer_cond))))
/* Invert comparisons if necessary (and possible). */
if (inner_inv)
inner_cond_code = invert_tree_comparison (inner_cond_code,
HONOR_NANS (TYPE_MODE (TREE_TYPE (gimple_cond_lhs (inner_cond)))));
if (inner_cond_code == ERROR_MARK)
return false;
if (outer_inv)
outer_cond_code = invert_tree_comparison (outer_cond_code,
HONOR_NANS (TYPE_MODE (TREE_TYPE (gimple_cond_lhs (outer_cond)))));
if (outer_cond_code == ERROR_MARK)
return false;
/* Don't return false so fast, try maybe_fold_or_comparisons? */
if (!(t = maybe_fold_and_comparisons (inner_cond_code,
gimple_cond_lhs (inner_cond),
gimple_cond_rhs (inner_cond),
outer_cond_code,
gimple_cond_lhs (outer_cond),
gimple_cond_rhs (outer_cond))))
return false;
if (result_inv)
t = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (t), t);
t = canonicalize_cond_expr_cond (t);
if (!t)
return false;
@ -530,7 +494,8 @@ ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
update_stmt (inner_cond);
/* Leave CFG optimization to cfg_cleanup. */
gimple_cond_set_condition_from_tree (outer_cond, boolean_false_node);
gimple_cond_set_condition_from_tree (outer_cond,
outer_inv ? boolean_false_node : boolean_true_node);
update_stmt (outer_cond);
if (dump_file)
@ -587,7 +552,26 @@ tree_ssa_ifcombine_bb (basic_block inner_cond_bb)
<else_bb>
...
*/
return ifcombine_ifandif (inner_cond_bb, outer_cond_bb);
return ifcombine_ifandif (inner_cond_bb, false, outer_cond_bb, false,
false);
}
/* And a version where the outer condition is negated. */
if (recognize_if_then_else (outer_cond_bb, &else_bb, &inner_cond_bb)
&& same_phi_args_p (outer_cond_bb, inner_cond_bb, else_bb)
&& bb_no_side_effects_p (inner_cond_bb))
{
/* We have
<outer_cond_bb>
if (q) goto else_bb; else goto inner_cond_bb;
<inner_cond_bb>
if (p) goto ...; else goto else_bb;
...
<else_bb>
...
*/
return ifcombine_ifandif (inner_cond_bb, false, outer_cond_bb, true,
false);
}
/* The || form is characterized by a common then_bb with the
@ -606,7 +590,25 @@ tree_ssa_ifcombine_bb (basic_block inner_cond_bb)
<then_bb>
...
*/
return ifcombine_iforif (inner_cond_bb, outer_cond_bb);
return ifcombine_ifandif (inner_cond_bb, true, outer_cond_bb, true,
true);
}
/* And a version where the outer condition is negated. */
if (recognize_if_then_else (outer_cond_bb, &inner_cond_bb, &then_bb)
&& same_phi_args_p (outer_cond_bb, inner_cond_bb, then_bb)
&& bb_no_side_effects_p (inner_cond_bb))
{
/* We have
<outer_cond_bb>
if (q) goto inner_cond_bb; else goto then_bb;
<inner_cond_bb>
if (q) goto then_bb; else goto ...;
<then_bb>
...
*/
return ifcombine_ifandif (inner_cond_bb, true, outer_cond_bb, false,
true);
}
}