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re PR tree-optimization/31982 (Missed forw prop with indirect ref and addr. (and char types or sizeof(type) == 1))

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2007-05-24  Richard Guenther  <rguenther@suse.de>
        Andrew Pinski  <andrew_pinski@playstation.sony.com>

	PR tree-optimization/31982
	* tree-ssa-forwprop.c
	(forward_propagate_addr_into_variable_array_index): Handle arrays
	with element size one.

	* gcc.dg/tree-ssa/forwprop-2.c: New testcase.

Co-Authored-By: Andrew Pinski <andrew_pinski@playstation.sony.com>

From-SVN: r125058
This commit is contained in:
Richard Guenther 2007-05-25 09:07:29 +00:00 • committed by Richard Biener
parent 3603271035
commit 88efe45a92
4 changed files with 56 additions and 19 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2007-05-25 Richard Guenther <rguenther@suse.de>
PR tree-optimization/31982
* tree-ssa-forwprop.c
(forward_propagate_addr_into_variable_array_index): Handle arrays
with element size one.
2007-05-24 Andrew Pinski <andrew_pinski@playstation.sony.com>
* config/spu/spu.md (smulsi3_highpart): Unshare the rtl chain.

6
gcc/testsuite/ChangeLog
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@ -1,3 +1,9 @@
2007-05-25 Richard Guenther <rguenther@suse.de>
Andrew Pinski <andrew_pinski@playstation.sony.com>
PR tree-optimization/31982
* gcc.dg/tree-ssa/forwprop-2.c: New testcase.
2007-05-25 Paul Thomas <pault@gcc.gnu.org>
PR fortran/32047

22
gcc/testsuite/gcc.dg/tree-ssa/forwprop-2.c Normal file
View file

@ -0,0 +1,22 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-forwprop" } */
/* We should be able to optimize this to b->t[i] = 1 during
early optimizations. */
struct a
{
char t[10];
};
struct a *b;
void f(__SIZE_TYPE__ i)
{
char *c = b->t;
c[i] = 1;
}
/* { dg-final { scan-tree-dump "t\\\[i.*\\\] = 1;" "forwprop1" { xfail *-*-* } } } */
/* { dg-final { scan-tree-dump "t\\\[i.*\\\] = 1;" "forwprop2" } } */
/* { dg-final { cleanup-tree-dump "forwprop?" } } */

40
gcc/tree-ssa-forwprop.c
View file

@ -513,28 +513,30 @@ forward_propagate_addr_into_variable_array_index (tree offset, tree lhs,
if (TREE_CODE (offset) != SSA_NAME)
return false;
/* Get the defining statement of the offset before type
conversion. */
offset = SSA_NAME_DEF_STMT (offset);
/* Try to find an expression for a proper index. This is either
a multiplication expression by the element size or just the
ssa name we came along in case the element size is one. */
if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (lhs)))))
index = offset;
else
{
offset = SSA_NAME_DEF_STMT (offset);
/* The statement which defines OFFSET before type conversion
must be a simple GIMPLE_MODIFY_STMT. */
if (TREE_CODE (offset) != GIMPLE_MODIFY_STMT)
return false;
/* The RHS of the statement which defines OFFSET must be a
multiplication of an object by the size of the array elements. */
if (TREE_CODE (offset) != GIMPLE_MODIFY_STMT)
return false;
/* The RHS of the statement which defines OFFSET must be a
multiplication of an object by the size of the array elements.
This implicitly verifies that the size of the array elements
is constant. */
offset = GIMPLE_STMT_OPERAND (offset, 1);
if (TREE_CODE (offset) != MULT_EXPR
|| TREE_CODE (TREE_OPERAND (offset, 1)) != INTEGER_CST
|| !simple_cst_equal (TREE_OPERAND (offset, 1),
TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (lhs)))))
return false;
offset = GIMPLE_STMT_OPERAND (offset, 1);
if (TREE_CODE (offset) != MULT_EXPR
|| TREE_CODE (TREE_OPERAND (offset, 1)) != INTEGER_CST
|| !simple_cst_equal (TREE_OPERAND (offset, 1),
TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (lhs)))))
return false;
/* The first operand to the MULT_EXPR is the desired index. */
index = TREE_OPERAND (offset, 0);
/* The first operand to the MULT_EXPR is the desired index. */
index = TREE_OPERAND (offset, 0);
}
/* Replace the pointer addition with array indexing. */
GIMPLE_STMT_OPERAND (use_stmt, 1) = unshare_expr (def_rhs);