PATCH: PR tree-optimization/35494: [4.4 Regression]: Revision 132991 breaks 483.xalancbmk
Andrew Pinski
pinskia@gmail.com
Sat Mar 8 23:32:00 GMT 2008
Sent from my iPhone
On Mar 8, 2008, at 15:15, "H.J. Lu" <hjl.tools@gmail.com> wrote:
> On Sat, Mar 08, 2008 at 09:44:13PM +0100, Richard Guenther wrote:
>> On Fri, Mar 7, 2008 at 11:07 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> On Fri, Mar 7, 2008 at 11:11 AM, H.J. Lu <hjl.tools@gmail.com>
>>> wrote:
>>>> Compiler will allocate space for
>>>>
>>>> const int conststaticvariable;
>>>>
>>>> You just may not know what value will be in all cases. Here is the
>>>> updated with additional testcases. OK to install if tests on
>>>> Linux/x86
>>>> and Linux/Intel64 as well as 483.xalancbmk passes?
>>>>
>>>
>>> All tests are passed. OK to install on trunk?
>>
>> Yes.
>>
>
> It turns out to be a tricky issue. We need to check if a read-only
> symbol may be overridden at both run time and link time. I can't
> use targetm.binds_local_p since it only tells me if a symbol may be
> overridden at run time by another module. It returns fals positive
> for
>
> class Foo {
> public:
> static const int erf = 0;
> };
>
> since C++ sets DECL_EXTERNAL to 1. Also it doesn't tell me if a
> symbol may be overridden by another definition at link time. I
>
> I opened PR 35501 for run time issue. I am testing this patch for
> both PR 35494 and 35501 on Linux/ia32 and Linux/Intel as well as
> 483.xalancbmk. OK to install if all tests pass?
>
>
> H.J.
> ---
> gcc/
>
> 2008-03-08 H.J. Lu <hongjiu.lu@intel.com>
>
> PR tree-optimization/35501
> * c-typeck.c (decl_constant_value): Check if value may be
> overriden at run time.
> * tree-ssa-sccvn.c (try_to_simplify): Likewise.
>
> PR tree-optimization/35494
> PR tree-optimization/35501
> * tree-ssa-ccp.c (get_symbol_constant_value): Check if value
> may be overriden at link and run time.
>
> gcc/testsuite/
>
> 2008-03-07 H.J. Lu <hongjiu.lu@intel.com>
>
> PR tree-optimization/35494
> * g++.dg/tree-ssa/ssa-store-ccp-1.C: New.
> * gcc.dg/tree-ssa/ssa-store-ccp-2.c: Likewise.
> * gcc.dg/tree-ssa/ssa-store-ccp-3.c: Likewise.
> * gcc.dg/tree-ssa/ssa-store-ccp-4.c: Likewise.
>
> PR tree-optimization/35501
> * gcc.dg/pr35501-1.c: New.
> * gcc.dg/pr35501-2.c: Likewise.
> * gcc.dg/pr35501-3.c: Likewise.
> * gcc.dg/pr35501-4.c: Likewise.
>
> --- gcc/c-typeck.c.local 2008-02-26 09:27:22.000000000 -0800
> +++ gcc/c-typeck.c 2008-03-08 14:44:29.000000000 -0800
> @@ -1551,7 +1551,10 @@ decl_constant_value (tree decl)
> or a variable, then re-evaluating it could give different
> results. */
> && TREE_CONSTANT (DECL_INITIAL (decl))
> /* Check for cases where this is sub-optimal, even though
> valid. */
> - && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
> + && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR
> + /* Check if it may be overriden at run time. */
> + && (!flag_shlib
> + || DECL_VISIBILITY (decl) != VISIBILITY_DEFAULT))
> return DECL_INITIAL (decl);
This is only true with elf semantics; mach-o semantics say that a
variable in a shared library is not overwritable.
>
> return decl;
> }
> --- gcc/testsuite/g++.dg/tree-ssa/ssa-store-ccp-1.C.local
> 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/g++.dg/tree-ssa/ssa-store-ccp-1.C 2008-03-08
> 14:48:55.000000000 -0800
> @@ -0,0 +1,19 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +class bar
> +{
> +public:
> + static const int conststaticvariable;
> +};
> +
> +
> +int f(void)
> +{
> + return bar::conststaticvariable;
> +}
> +
> +/* There should be a reference to conststaticvariable since it may
> + be overriden at link time. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 1
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/pr35501-1.c.local 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/pr35501-1.c 2008-03-08 14:44:29.000000000 -0800
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-optimized" } */
> +
> +const int conststaticvariable = 1;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be no reference to conststaticvariable as we should
> have
> + inlined the 0. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 0
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/pr35501-2.c.local 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/pr35501-2.c 2008-03-08 14:44:29.000000000 -0800
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +const int conststaticvariable = 1;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be no reference to conststaticvariable as we should
> have
> + inlined the 0. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 0
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/pr35501-3.c.local 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/pr35501-3.c 2008-03-08 14:50:02.000000000 -0800
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target fpic } */
> +/* { dg-options "-O -fpic -fdump-tree-optimized" } */
> +
> +const int conststaticvariable = 1;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be a reference to conststaticvariable since it may
> + may be overriden at run time. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 1
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/pr35501-4.c.local 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/pr35501-4.c 2008-03-08 14:50:10.000000000 -0800
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target fpic } */
> +/* { dg-options "-O2 -fpic -fdump-tree-optimized" } */
> +
> +const int conststaticvariable = 1;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be a reference to conststaticvariable since it may
> + may be overriden at run time. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 1
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-2.c.local
> 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-2.c 2008-03-08
> 14:48:43.000000000 -0800
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +const int conststaticvariable;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be a reference to conststaticvariable since it may
> + may be overriden at link time. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 1
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-3.c.local
> 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-3.c 2008-03-08
> 14:44:29.000000000 -0800
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fno-common -fdump-tree-optimized" } */
> +
> +const int conststaticvariable;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be no reference to conststaticvariable as we should
> have
> + inlined the 0. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 0
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-4.c.local
> 2008-03-08 14:44:29.000000000 -0800
> +++ gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-4.c 2008-03-08
> 14:49:35.000000000 -0800
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target fpic } */
> +/* { dg-options "-O2 -fno-common -fpic -fdump-tree-optimized" } */
> +
> +const int conststaticvariable;
> +
> +int f(void)
> +{
> + return conststaticvariable;
> +}
> +
> +/* There should be a reference to conststaticvariable since it may
> + may be overriden at run time. */
> +/* { dg-final { scan-tree-dump-times "conststaticvariable" 1
> "optimized"} } */
> +/* { dg-final { cleanup-tree-dump "optimized" } } */
> --- gcc/tree-ssa-ccp.c.local 2008-03-07 09:02:37.000000000 -0800
> +++ gcc/tree-ssa-ccp.c 2008-03-08 14:52:43.000000000 -0800
> @@ -300,15 +300,21 @@ get_symbol_constant_value (tree sym)
> {
> if (TREE_STATIC (sym)
> && TREE_READONLY (sym)
> - && !MTAG_P (sym))
> + && !MTAG_P (sym)
> + /* Check if a read-only definition may be overridden at
> + run time. */
> + && (!flag_shlib
> + || DECL_VISIBILITY (sym) != VISIBILITY_DEFAULT))
> {
> tree val = DECL_INITIAL (sym);
> if (val
> && ccp_decl_initial_min_invariant (val))
> return val;
> - /* Variables declared 'const' without an initializer
> - have zero as the intializer. */
> + /* Variables declared 'const' without an initializer have
> + zero as the intializer if it won't be overridden at
> + link time. */
> if (!val
> + && (!TREE_PUBLIC (sym) || !DECL_EXTERNAL (sym))
> && (INTEGRAL_TYPE_P (TREE_TYPE (sym))
> || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym))))
> return fold_convert (TREE_TYPE (sym), integer_zero_node);
> --- gcc/tree-ssa-sccvn.c.local 2008-03-08 14:41:18.000000000 -0800
> +++ gcc/tree-ssa-sccvn.c 2008-03-08 14:44:29.000000000 -0800
> @@ -1453,6 +1453,9 @@ try_to_simplify (tree stmt, tree rhs)
> if (TREE_READONLY (rhs)
> && TREE_STATIC (rhs)
> && DECL_INITIAL (rhs)
> + /* Check if it may be overriden at run time. */
> + && (!flag_shlib
> + || DECL_VISIBILITY (rhs) != VISIBILITY_DEFAULT)
> && valid_gimple_expression_p (DECL_INITIAL (rhs)))
> return DECL_INITIAL (rhs);
>
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