On Thu, Oct 31, 2013 at 10:02 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
> Hi,
>
> Here is a patch which hadles the problem with optimization of
> BUILT_IN_CHKP_ARG_BND calls. Pointer Bounds Checker expects that argument of
> this call is a default SSA_NAME of the PARM_DECL whose bounds we want to get.
> The problem is in optimizations which may replace arg with it's copy or a
> known value. This patch suppress such modifications.
This doesn't seem like a good fix. I suppose you require the same on
RTL, that is, have the incoming arg reg coalesced with the use?
In that case better set SSA_NAME_OCCURS_IN_ABNORMAL_PHI.
Richard.
> Thanks,
> Ilya
> --
>
> gcc/
>
> 2013-10-28 Ilya Enkovich <ilya.enkov...@intel.com>
>
> * tree-into-ssa.c: Include "target.h"
> (rewrite_update_stmt): Skip BUILT_IN_CHKP_ARG_BND calls.
> * tree-ssa-dom.c: Include "target.h"
> (cprop_into_stmt): Skip BUILT_IN_CHKP_ARG_BND calls.
>
>
> diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c
> index 981e9f4..8d48f6d 100644
> --- a/gcc/tree-into-ssa.c
> +++ b/gcc/tree-into-ssa.c
> @@ -46,6 +46,7 @@ along with GCC; see the file COPYING3. If not see
> #include "params.h"
> #include "diagnostic-core.h"
> #include "tree-into-ssa.h"
> +#include "target.h"
>
>
> /* This file builds the SSA form for a function as described in:
> @@ -1921,8 +1922,14 @@ rewrite_update_stmt (gimple stmt, gimple_stmt_iterator
> gsi)
> }
>
> /* Rewrite USES included in OLD_SSA_NAMES and USES whose underlying
> - symbol is marked for renaming. */
> - if (rewrite_uses_p (stmt))
> + symbol is marked for renaming.
> + Skip calls to BUILT_IN_CHKP_ARG_BND whose arg should never be
> + renamed. */
> + if (rewrite_uses_p (stmt)
> + && !(flag_check_pointer_bounds
> + && (gimple_code (stmt) == GIMPLE_CALL)
> + && gimple_call_fndecl (stmt)
> + == targetm.builtin_chkp_function (BUILT_IN_CHKP_ARG_BND)))
> {
> if (is_gimple_debug (stmt))
> {
> diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
> index 211bfcf..445278a 100644
> --- a/gcc/tree-ssa-dom.c
> +++ b/gcc/tree-ssa-dom.c
> @@ -45,6 +45,7 @@ along with GCC; see the file COPYING3. If not see
> #include "params.h"
> #include "tree-ssa-threadedge.h"
> #include "tree-ssa-dom.h"
> +#include "target.h"
>
> /* This file implements optimizations on the dominator tree. */
>
> @@ -2266,6 +2267,16 @@ cprop_into_stmt (gimple stmt)
> use_operand_p op_p;
> ssa_op_iter iter;
>
> + /* Call used to obtain bounds of input arg by Pointer Bounds Checker
> + should not be optimized. Argument of the call is a default
> + SSA_NAME of PARM_DECL. It should never be replaced by value. */
> + if (flag_check_pointer_bounds && gimple_code (stmt) == GIMPLE_CALL)
> + {
> + tree fndecl = gimple_call_fndecl (stmt);
> + if (fndecl == targetm.builtin_chkp_function (BUILT_IN_CHKP_ARG_BND))
> + return;
> + }
> +
> FOR_EACH_SSA_USE_OPERAND (op_p, stmt, iter, SSA_OP_USE)
> cprop_operand (stmt, op_p);
> }
