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ubsan.c (instrument_object_size): Optimize [x & CST] array accesses.

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* ubsan.c (instrument_object_size): Optimize [x & CST] array accesses.
testsuite/
	* c-c++-common/ubsan/object-size-10.c: New test.

From-SVN: r217071
This commit is contained in:
Marek Polacek 2014-11-04 09:30:47 +00:00 committed by Marek Polacek
parent 107bdb31ee
commit 74e3d997b3
4 changed files with 108 additions and 0 deletions
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4
gcc/ChangeLog
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@ -1,3 +1,7 @@
2014-11-04 Marek Polacek <polacek@redhat.com>
* ubsan.c (instrument_object_size): Optimize [x & CST] array accesses.
2014-11-03 Jan-Benedict Glaw <jbglaw@lug-owl.de>
* config/rx/rx.c (rx_handle_func_attribute): Mark unused argument.

4
gcc/testsuite/ChangeLog
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@ -1,3 +1,7 @@
2014-11-04 Marek Polacek <polacek@redhat.com>
* c-c++-common/ubsan/object-size-10.c: New test.
2014-11-03 Dominik Vogt <vogt@linux.vnet.ibm.com>
* build-go/gcc/testsuite/gcc/godump-1.out: Update godump tests.

79
gcc/testsuite/c-c++-common/ubsan/object-size-10.c Normal file
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@ -0,0 +1,79 @@
/* { dg-do run } */
/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
/* { dg-options "-fsanitize=undefined" } */
static char a[128];
static int b[128];
__attribute__ ((noinline, noclone)) int
fn1 (int i)
{
asm ("");
return a[i & 127];
}
__attribute__ ((noinline, noclone)) int
fn2 (int i)
{
asm ("");
return a[i & 128];
}
/* { dg-output "index 128 out of bounds for type 'char \\\[128\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*load of address \[^\n\r]* with insufficient space for an object of type 'char'\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*\\^\[^\n\r]*(\n|\r\n|\r)" } */
__attribute__ ((noinline, noclone)) int
fn3 (int i)
{
asm ("");
return b[i & 127];
}
__attribute__ ((noinline, noclone)) int
fn4 (int i)
{
asm ("");
return b[i & 128];
}
/* { dg-output "\[^\n\r]*index 128 out of bounds for type 'int \\\[128\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*load of address \[^\n\r]* with insufficient space for an object of type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*\\^\[^\n\r]*(\n|\r\n|\r)" } */
__attribute__ ((noinline, noclone)) int
fn5 (int i, int j)
{
asm ("");
return b[i & j];
}
/* { dg-output "\[^\n\r]*index 128 out of bounds for type 'int \\\[128\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*load of address \[^\n\r]* with insufficient space for an object of type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*note: pointer points here\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*\[^\n\r]*(\n|\r\n|\r)" } */
/* { dg-output "\[^\n\r]*\\^\[^\n\r]*(\n|\r\n|\r)" } */
__attribute__ ((noinline, noclone)) int
fn6 (int i)
{
asm ("");
return b[i & 0];
}
int
main (void)
{
fn1 (128);
fn2 (128);
fn3 (128);
fn4 (128);
fn5 (128, 127);
fn5 (128, 128);
fn6 (128);
return 0;
}

21
gcc/ubsan.c
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@ -1438,6 +1438,7 @@ instrument_object_size (gimple_stmt_iterator *gsi, bool is_lhs)
location_t loc = gimple_location (stmt);
tree t = is_lhs ? gimple_get_lhs (stmt) : gimple_assign_rhs1 (stmt);
tree type;
tree index = NULL_TREE;
HOST_WIDE_INT size_in_bytes;
type = TREE_TYPE (t);
@ -1456,6 +1457,8 @@ instrument_object_size (gimple_stmt_iterator *gsi, bool is_lhs)
}
break;
case ARRAY_REF:
index = TREE_OPERAND (t, 1);
break;
case INDIRECT_REF:
case MEM_REF:
case VAR_DECL:
@ -1537,6 +1540,24 @@ instrument_object_size (gimple_stmt_iterator *gsi, bool is_lhs)
&& tree_int_cst_le (t, sizet))
return;
if (index != NULL_TREE
&& TREE_CODE (index) == SSA_NAME
&& TREE_CODE (sizet) == INTEGER_CST)
{
gimple def = SSA_NAME_DEF_STMT (index);
if (is_gimple_assign (def)
&& gimple_assign_rhs_code (def) == BIT_AND_EXPR
&& TREE_CODE (gimple_assign_rhs2 (def)) == INTEGER_CST)
{
tree cst = gimple_assign_rhs2 (def);
tree sz = fold_build2 (EXACT_DIV_EXPR, sizetype, sizet,
TYPE_SIZE_UNIT (type));
if (tree_int_cst_sgn (cst) >= 0
&& tree_int_cst_lt (cst, sz))
return;
}
}
/* Nope. Emit the check. */
t = force_gimple_operand_gsi (gsi, t, true, NULL_TREE, true,
GSI_SAME_STMT);