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re PR tree-optimization/33723 (Inefficient code with compound literals)

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PR tree-optimization/33723
	* c-gimplify.c (c_gimplify_expr): Optimize INIT_EXPR or
	MODIFY_EXPR with non-addressable COMPOUND_LITERAL_EXPR as source.

	* gcc.c-torture/execute/20071029-1.c: New test.
	* gcc.dg/tree-ssa/pr33723.c: New test.

From-SVN: r129743
This commit is contained in:
Jakub Jelinek 2007-10-29 23:26:59 +01:00 • committed by Jakub Jelinek
parent 9f1da821e6
commit 489f2598af
5 changed files with 165 additions and 0 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2007-10-29 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/33723
* c-gimplify.c (c_gimplify_expr): Optimize INIT_EXPR or
MODIFY_EXPR with non-addressable COMPOUND_LITERAL_EXPR as source.
2007-10-29 Richard Sandiford <rsandifo@nildram.co.uk>
PR tree-optimization/33614

23
gcc/c-gimplify.c
View file

@ -233,6 +233,29 @@ c_gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p ATTRIBUTE_UNUSED)
case COMPOUND_LITERAL_EXPR:
return gimplify_compound_literal_expr (expr_p, pre_p);
case INIT_EXPR:
case MODIFY_EXPR:
if (TREE_CODE (TREE_OPERAND (*expr_p, 1)) == COMPOUND_LITERAL_EXPR)
{
tree complit = TREE_OPERAND (*expr_p, 1);
tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (complit);
tree decl = DECL_EXPR_DECL (decl_s);
tree init = DECL_INITIAL (decl);
/* struct T x = (struct T) { 0, 1, 2 } can be optimized
into struct T x = { 0, 1, 2 } if the address of the
compound literal has never been taken. */
if (!TREE_ADDRESSABLE (complit)
&& !TREE_ADDRESSABLE (decl)
&& init)
{
*expr_p = copy_node (*expr_p);
TREE_OPERAND (*expr_p, 1) = init;
return GS_OK;
}
}
return GS_UNHANDLED;
default:
return GS_UNHANDLED;
}

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2007-10-29 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/33723
* gcc.c-torture/execute/20071029-1.c: New test.
* gcc.dg/tree-ssa/pr33723.c: New test.
2007-10-29 Richard Sandiford <rsandifo@nildram.co.uk>
PR tree-optimization/33614

56
gcc/testsuite/gcc.c-torture/execute/20071029-1.c Normal file
View file

@ -0,0 +1,56 @@
extern void exit (int);
extern void abort (void);
typedef union
{
struct
{
int f1, f2, f3, f4, f5, f6, f7, f8;
long int f9, f10;
int f11;
} f;
char s[56];
long int a;
} T;
__attribute__((noinline))
void
test (T *t)
{
static int i = 11;
if (t->f.f1 != i++)
abort ();
if (t->f.f2 || t->f.f3 || t->f.f4 || t->f.f5 || t->f.f6
|| t->f.f7 || t->f.f8 || t->f.f9 || t->f.f10 || t->f.f11)
abort ();
if (i == 20)
exit (0);
}
__attribute__((noinline))
void
foo (int i)
{
T t;
again:
t = (T) { { ++i, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } };
test (&t);
goto again;
}
int
main (void)
{
T *t1, *t2;
int cnt = 0;
t1 = (T *) 0;
loop:
t2 = t1;
t1 = & (T) { .f.f9 = cnt++ };
if (cnt < 3)
goto loop;
if (t1 != t2 || t1->f.f9 != 2)
abort ();
foo (10);
return 0;
}

74
gcc/testsuite/gcc.dg/tree-ssa/pr33723.c Normal file
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@ -0,0 +1,74 @@
/* PR tree-optimization/33723 */
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-gimple" } */
typedef union
{
struct
{
int f1, f2, f3, f4, f5, f6, f7, f8;
long int f9, f10;
int f11;
} f;
char s[56];
long int a;
} T;
void
foo1 (void)
{
T t;
t = (T) { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } };
test (&t);
}
void
bar1 (void)
{
T t = { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } };
test (&t);
}
void
baz1 (void)
{
T t;
t = (const T) { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } };
test (&t);
}
void
foo2 (void)
{
T t;
t = (T) { { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 } };
test (&t);
}
void
bar2 (void)
{
T t = { { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 } };
test (&t);
}
void
baz2 (void)
{
T t;
t = (const T) { { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 } };
test (&t);
}
void
baz3 (void)
{
T t;
t = (const T) (T) { { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 } };
test (&t);
}
/* { dg-final { scan-tree-dump-times "t = {}" 3 "gimple"} } */
/* { dg-final { scan-tree-dump-times "t.f.f1 = 1" 4 "gimple"} } */
/* { dg-final { scan-tree-dump-times "t.f.f8 = 8" 4 "gimple"} } */
/* { dg-final { cleanup-tree-dump "gimple" } } */