On Mon, 2 Dec 2013, Richard Biener wrote:
> On Mon, 2 Dec 2013, Jakub Jelinek wrote:
>
> > On Mon, Dec 02, 2013 at 12:05:57PM +0100, Richard Biener wrote:
> > >
> > > The following fixes a bug in update_address_taken which fails
> > > to reset debug stmts which take the address of a decl we will
> > > rewrite into SSA form. Our verifiers don't catch this because
> > > of an early out in the operand scanner which doesn't work in
> > > the specific case of LTO profiledbootstrap (or because we
> > > don't have more specific checking for this case).
> > >
> > > Fixed like the following.
> > >
> > > LTO profiledbootstrapped on x86_64-unknown-linux-gnu, regular
> > > bootstrap & regtest still running.
> >
> > Taking address of a decl that is no longer addressable in debug stmts
> > is correct, that is how we generate DW_OP_GNU_implicit_ptr.
> > So I think this patch is going to cause huge amount of debug info quality
> > regressions.
>
> Does it? Note the decls in question will be renamed to SSA form,
> so not sure what "implicit" pointer you'll build here...? And
> what can you do with that pointer inside the debugger?
>
> If that's desired IL (having both DECL and SSA_NAMEs of that DECL
> in the IL) then explicit support for this needs to be added to
> the operand scanner.
Like the following, LTO profilebootstrapped on x86_64-unknown-linux-gnu,
bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
(must resist applying more TLC to tree-ssa-operands.c at this point...)
Richard.
2013-12-02 Richard Biener <rguent...@suse.de>
* tree-ssa-operands.c (opf_implicit): Remove.
(opf_address_taken): New flag.
(get_expr_operands): Remove early out, pass down
opf_address_taken for ADDR_EXPRs, add a use operand only
for non-opf_address_taken bases.
(get_indirect_ref_operands): Rename to ...
(get_mem_ref_operands): ... this.
(get_asm_expr_operands): Rename to ...
(get_asm_stmt_operands): ... this.
Index: gcc/tree-ssa-operands.c
===================================================================
*** gcc/tree-ssa-operands.c (revision 205585)
--- gcc/tree-ssa-operands.c (working copy)
*************** along with GCC; see the file COPYING3.
*** 105,121 ****
VUSE for 'b'. */
#define opf_no_vops (1 << 1)
- /* Operand is an implicit reference. This is used to distinguish
- explicit assignments in the form of MODIFY_EXPR from
- clobbering sites like function calls or ASM_EXPRs. */
- #define opf_implicit (1 << 2)
-
/* Operand is in a place where address-taken does not imply addressable. */
#define opf_non_addressable (1 << 3)
/* Operand is in a place where opf_non_addressable does not apply. */
#define opf_not_non_addressable (1 << 4)
/* Array for building all the use operands. */
static vec<tree> build_uses;
--- 105,119 ----
VUSE for 'b'. */
#define opf_no_vops (1 << 1)
/* Operand is in a place where address-taken does not imply addressable. */
#define opf_non_addressable (1 << 3)
/* Operand is in a place where opf_non_addressable does not apply. */
#define opf_not_non_addressable (1 << 4)
+ /* Operand is having its address taken. */
+ #define opf_address_taken (1 << 5)
+
/* Array for building all the use operands. */
static vec<tree> build_uses;
*************** mark_address_taken (tree ref)
*** 597,604 ****
FLAGS is as in get_expr_operands. */
static void
! get_indirect_ref_operands (struct function *fn,
! gimple stmt, tree expr, int flags)
{
tree *pptr = &TREE_OPERAND (expr, 0);
--- 595,602 ----
FLAGS is as in get_expr_operands. */
static void
! get_mem_ref_operands (struct function *fn,
! gimple stmt, tree expr, int flags)
{
tree *pptr = &TREE_OPERAND (expr, 0);
*************** maybe_add_call_vops (struct function *fn
*** 664,670 ****
/* Scan operands in the ASM_EXPR stmt referred to in INFO. */
static void
! get_asm_expr_operands (struct function *fn, gimple stmt)
{
size_t i, noutputs;
const char **oconstraints;
--- 662,668 ----
/* Scan operands in the ASM_EXPR stmt referred to in INFO. */
static void
! get_asm_stmt_operands (struct function *fn, gimple stmt)
{
size_t i, noutputs;
const char **oconstraints;
*************** get_expr_operands (struct function *fn,
*** 750,760 ****
&& !is_gimple_debug (stmt))
mark_address_taken (TREE_OPERAND (expr, 0));
- /* If the address is invariant, there may be no interesting
- variable references inside. */
- if (is_gimple_min_invariant (expr))
- return;
-
/* Otherwise, there may be variables referenced inside but there
should be no VUSEs created, since the referenced objects are
not really accessed. The only operands that we should find
--- 748,753 ----
*************** get_expr_operands (struct function *fn,
*** 762,775 ****
(GIMPLE does not allow non-registers as array indices). */
flags |= opf_no_vops;
get_expr_operands (fn, stmt, &TREE_OPERAND (expr, 0),
! flags | opf_not_non_addressable);
return;
case SSA_NAME:
case VAR_DECL:
case PARM_DECL:
case RESULT_DECL:
! add_stmt_operand (fn, expr_p, stmt, flags);
return;
case DEBUG_EXPR_DECL:
--- 755,769 ----
(GIMPLE does not allow non-registers as array indices). */
flags |= opf_no_vops;
get_expr_operands (fn, stmt, &TREE_OPERAND (expr, 0),
! flags | opf_not_non_addressable | opf_address_taken);
return;
case SSA_NAME:
case VAR_DECL:
case PARM_DECL:
case RESULT_DECL:
! if (!(flags & opf_address_taken))
! add_stmt_operand (fn, expr_p, stmt, flags);
return;
case DEBUG_EXPR_DECL:
*************** get_expr_operands (struct function *fn,
*** 777,783 ****
return;
case MEM_REF:
! get_indirect_ref_operands (fn, stmt, expr, flags);
return;
case TARGET_MEM_REF:
--- 771,777 ----
return;
case MEM_REF:
! get_mem_ref_operands (fn, stmt, expr, flags);
return;
case TARGET_MEM_REF:
*************** parse_ssa_operands (struct function *fn,
*** 921,927 ****
switch (code)
{
case GIMPLE_ASM:
! get_asm_expr_operands (fn, stmt);
break;
case GIMPLE_TRANSACTION:
--- 915,921 ----
switch (code)
{
case GIMPLE_ASM:
! get_asm_stmt_operands (fn, stmt);
break;
case GIMPLE_TRANSACTION:
