On 4 July 2016 at 15:17, Richard Biener <richard.guent...@gmail.com> wrote:
> On Sun, Jul 3, 2016 at 9:34 AM, Prasad Ghangal <prasad.ghan...@gmail.com>
> wrote:
>> In this patch, I am passing labels and vars with internal function and
>> handling them in tree-cfg for parsing PHI.
>> For first label, label_to_block() gives correct basic block and I am
>> getting proper edges but for other labels the function is giving NULL.
>>
>> test-case :
>>
>> void __GIMPLE () foo()
>> {
>> int a;
>> int a_2;
>> int a_3;
>> int a_1;
>>
>> bb_2:
>> a_2 = 3;
>> goto bb_4;
>>
>> bb_3:
>> a_3 = 6;
>> goto bb_4;
>>
>> bb_4:
>> a_1 = __PHI (bb_2: a_2, bb_3: a_3);
>> a_1 = a_1 + 1;
>> return;
>> }
>>
>
> The issue is probably you lower PHIs after cleanup_tree_cfg is run which may
> end up removing labels. Or it is cleanup_dead_labels in build_gimple_cfg.
Yes, that was due to cleanup_dead_label. It is working after calling
lower_phi_internal_fn just after make_edges
So test case like:
void __GIMPLE () foo()
{
int a;
int a_2;
int a_3;
int a_1;
int a_0;
bb_2:
if (a > 4)
goto bb_3;
else
goto bb_4;
bb_3:
a_2 = 6;
goto bb_5;
bb_4:
a_3 = 99;
goto bb_5;
bb_5:
a_1 = __PHI (bb_3: a_2, bb_4: a_3);
a_0 = a_1 + 1;
return;
}
produces ssa dump as
;; Function foo (foo, funcdef_no=0, decl_uid=1744, cgraph_uid=0, symbol_order=0)
foo ()
{
int a_0;
int a_1;
int a_3;
int a_2;
int a;
bb_2:
if (a_2(D) > 4)
goto <bb 3> (bb_3);
else
goto <bb 4> (bb_4);
bb_3:
a_2_3 = 6;
goto <bb 5> (bb_5);
bb_4:
a_3_5 = 99;
# a_1_1 = PHI <a_1_4(D)(3), a_1_4(D)(4)>
bb_5:
a_0_6 = a_1_1 + 1;
return;
}
and test case like :
void __GIMPLE () foo()
{
int a;
int a_2;
int a_3;
int a_1;
int a_0;
bb_3:
a_2 = 6;
goto bb_5;
bb_4:
a_3 = 99;
goto bb_5;
bb_5:
a_1 = __PHI (bb_3: a_2, bb_4: a_3);
a_0 = a_1 + 1;
return;
}
gets its block with bb_4 label removed as it is unreachable and
produces ssa dump as -
;; Function foo (foo, funcdef_no=0, decl_uid=1744, cgraph_uid=0, symbol_order=0)
foo ()
{
int a_0;
int a_1;
int a_3;
int a_2;
int a;
bb_3:
a_2_2 = 6;
# a_1_1 = PHI <a_1_3(D)(2)>
bb_5:
a_0_4 = a_1_1 + 1;
return;
}
I think which is fine(?).
Now ssa pass is producing ssa names for the vars because it expects
them with tree code SSA_NAME. How can we prevent this? Can we convert
VAR_DECL to SSA_NAME ?
>
> Richard.
>
>>
>>
>>
>> On 1 July 2016 at 17:33, Richard Biener <richard.guent...@gmail.com> wrote:
>>> On Fri, Jul 1, 2016 at 1:57 PM, Prasad Ghangal <prasad.ghan...@gmail.com>
>>> wrote:
>>>> On 29 June 2016 at 12:42, Richard Biener <richard.guent...@gmail.com>
>>>> wrote:
>>>>> On Tue, Jun 28, 2016 at 4:16 PM, Prasad Ghangal
>>>>> <prasad.ghan...@gmail.com> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> For handling PHI, it expects cfg to be built before. So I was
>>>>>> wondering how are we going to handle this? Do we need to build cfg
>>>>>> while parsing only?
>>>>>
>>>>> For handling PHIs we need to have a CFG in the sense that the GIMPLE PHI
>>>>> data structures are built in a way to have the PHI argument index
>>>>> correspond
>>>>> to CFG predecessor edge index. As we'd like to parse phis with args
>>>>> corresponding
>>>>> to predecessor block labels, like
>>>>>
>>>>> a:
>>>>> i_1 = 1;
>>>>> goto p;
>>>>>
>>>>> b:
>>>>> i_2 = 2;
>>>>> goto p;
>>>>>
>>>>> p:
>>>>> i_3 = __PHI (a: i_1, b: i_2);
>>>>>
>>>>> I think that a possibility is to leave those PHIs as internal function
>>>>> with label / arg
>>>>> pairs and have CFG construction lower them to real PHIs.
>>>>>
>>>>> Of course the parser could as well build a CFG on its own but I think
>>>>> we should use
>>>>> the easy way out for now.
>>>>>
>>>>> Thus you'd have to modify CFG construction a bit to lower the internal
>>>>> function calls.
>>>>
>>>> Currently I am just building internal call using
>>>> gimple_build_call_internal_vec (), and detecting (and removing for
>>>> now) it after edge creation in tree-cfg. I was observing
>>>> internal-fn.def, do I need to make entry in internal-fn.def and write
>>>> expand function?
>>>
>>> You should add an entry and a stub expand function (like those
>>> others that simply have gcc_unreachable in them).
>>>
>>> Richard.
>>>
>>>>>
>>>>> Richard.
>>>>>>
>>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Prasad
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index f2e62ca..138ca4f 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -512,6 +512,7 @@ const struct c_common_resword c_common_reswords[] =
{ "__volatile", RID_VOLATILE, 0 },
{ "__volatile__", RID_VOLATILE, 0 },
{ "__GIMPLE", RID_GIMPLE, D_CONLY },
+ { "__PHI", RID_PHI, D_CONLY},
{ "alignas", RID_ALIGNAS, D_CXXONLY | D_CXX11 | D_CXXWARN },
{ "alignof", RID_ALIGNOF, D_CXXONLY | D_CXX11 | D_CXXWARN },
{ "asm", RID_ASM, D_ASM },
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 23a401d..ede3549 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -107,6 +107,9 @@ enum rid
/* "__GIMPLE", for the GIMPLE-parsing extension to the C frontend. */
RID_GIMPLE,
+ /* "__PHI", for parsing PHI function in GIMPLE FE */
+ RID_PHI,
+
/* C11 */
RID_ALIGNAS, RID_GENERIC,
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index d62b8e8..00e0bc5 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -18345,6 +18345,57 @@ c_parser_gimple_expression (c_parser *parser,
gimple_seq *seq)
return;
}
+ if (c_parser_next_token_is_keyword (parser, RID_PHI))
+ {
+ c_parser_consume_token (parser);
+
+ if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>"))
+ {
+ return;
+ }
+
+ gcall *call_stmt;
+ /* Gimplify internal functions. */
+ tree arg;
+ vec<tree> vargs = vNULL;
+
+ if (c_parser_next_token_is (parser, CPP_OPEN_PAREN))
+ c_parser_consume_token (parser);
+
+ while (c_parser_next_token_is_not (parser, CPP_CLOSE_PAREN))
+ {
+ if (c_parser_next_token_is (parser, CPP_NAME) &&
+ c_parser_peek_2nd_token (parser)->type == CPP_COLON)
+ {
+ arg = lookup_label_for_goto (c_parser_peek_token
(parser)->location,
+ c_parser_peek_token (parser)->value);
+ c_parser_consume_token (parser);
+
+ if (c_parser_next_token_is (parser, CPP_COLON))
+ c_parser_consume_token (parser);
+ vargs.safe_push (arg);
+ }
+ else if (c_parser_next_token_is (parser, CPP_COMMA))
+ {
+ c_parser_consume_token (parser);
+ }
+ else
+ {
+ arg = c_parser_gimple_unary_expression (parser).value;
+ vargs.safe_push (arg);
+ }
+ }
+
+ c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
+ "expected %<)%>");
+
+ call_stmt = gimple_build_call_internal_vec (IFN_PHI, vargs);
+ gimple_call_set_lhs (call_stmt, lhs.value);
+ gimple_set_location (call_stmt, UNKNOWN_LOCATION);
+ gimple_seq_add_stmt (seq, call_stmt);
+ return;
+ }
+
exp_location = c_parser_peek_token (parser)->location;
rhs = c_parser_gimple_binary_expression (parser, &subcode);
rhs = convert_lvalue_to_rvalue (exp_location, rhs, true, true);
diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index c867ddc..eefa4e4 100644
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -2361,3 +2361,9 @@ expand_internal_call (gcall *stmt)
{
expand_internal_call (gimple_call_internal_fn (stmt), stmt);
}
+
+void
+expand_PHI (internal_fn, gcall *)
+{
+ gcc_unreachable ();
+}
diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
index e729d85..c385ab0 100644
--- a/gcc/internal-fn.def
+++ b/gcc/internal-fn.def
@@ -169,6 +169,7 @@ DEF_INTERNAL_FN (VA_ARG, ECF_NOTHROW | ECF_LEAF, NULL)
other such optimizations. The first argument distinguishes
between uses. See internal-fn.h for usage. */
DEF_INTERNAL_FN (UNIQUE, ECF_NOTHROW, NULL)
+DEF_INTERNAL_FN (PHI, 0, NULL)
/* DIM_SIZE and DIM_POS return the size of a particular compute
dimension and the executing thread's position within that
diff --git a/gcc/internal-fn.h b/gcc/internal-fn.h
index bb31465..9c39dd67 100644
--- a/gcc/internal-fn.h
+++ b/gcc/internal-fn.h
@@ -174,5 +174,6 @@ extern bool set_edom_supported_p (void);
extern void expand_internal_call (gcall *);
extern void expand_internal_call (internal_fn, gcall *);
+extern void expand_PHI (internal_fn, gcall *);
#endif
diff --git a/gcc/passes.c b/gcc/passes.c
index fd2f5cb..c84b4b1 100644
--- a/gcc/passes.c
+++ b/gcc/passes.c
@@ -114,7 +114,8 @@ pass_manager::execute_early_local_passes ()
execute_pass_list (cfun, pass_build_ssa_passes_1->sub);
if (flag_check_pointer_bounds)
execute_pass_list (cfun, pass_chkp_instrumentation_passes_1->sub);
- execute_pass_list (cfun, pass_local_optimization_passes_1->sub);
+ if (flag_gimple && cfun->custom_pass_list)
+ execute_pass_list (cfun, pass_local_optimization_passes_1->sub);
}
unsigned int
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 7fc24ba..3e34df8 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -169,6 +169,7 @@ static edge find_taken_edge_computed_goto (basic_block,
tree);
static edge find_taken_edge_cond_expr (basic_block, tree);
static edge find_taken_edge_switch_expr (gswitch *, basic_block, tree);
static tree find_case_label_for_value (gswitch *, tree);
+static void lower_phi_internal_fn ();
void
init_empty_tree_cfg_for_function (struct function *fn)
@@ -243,6 +244,7 @@ build_gimple_cfg (gimple_seq seq)
discriminator_per_locus = new hash_table<locus_discrim_hasher> (13);
make_edges ();
assign_discriminators ();
+ lower_phi_internal_fn ();
cleanup_dead_labels ();
delete discriminator_per_locus;
discriminator_per_locus = NULL;
@@ -344,6 +346,49 @@ replace_loop_annotate (void)
}
}
+/* Lower internal PHI function from GIMPLE FE */
+static void
+lower_phi_internal_fn ()
+{
+ basic_block bb, pred;
+ gimple_stmt_iterator gsi;
+ tree lhs;
+ gphi *phi_node;
+ gimple *stmt;
+ int len, capacity;
+ /* After edge creation, handle __PHI function from GIMPLE FE */
+
+ FOR_EACH_BB_FN (bb, cfun)
+ {
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ stmt = gsi_stmt (gsi);
+ if (gimple_code (stmt) != GIMPLE_CALL)
+ continue;
+
+ if (gimple_call_internal_p (stmt) && gimple_call_internal_fn (stmt)
== IFN_PHI)
+ {
+ gsi_remove (&gsi, true);
+ int i;
+ lhs = gimple_call_lhs (stmt);
+
+ phi_node = create_phi_node (lhs, bb);
+
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
+ {
+ tree arg = gimple_call_arg (stmt, i);
+ if (TREE_CODE (arg) == LABEL_DECL)
+ pred = label_to_block (arg);
+ else
+ {
+ edge e = find_edge (pred, bb);
+ add_phi_arg (phi_node, arg, e, UNKNOWN_LOCATION);
+ }
+ }
+ }
+ }
+ }
+}
static unsigned int
execute_build_cfg (void)
@@ -3339,6 +3384,11 @@ verify_gimple_call (gcall *stmt)
debug_generic_stmt (fn);
return true;
}
+ /* FIXME : for passing label as arg in internal fn PHI from GIMPLE FE*/
+ else if (gimple_call_internal_fn (stmt) == IFN_PHI)
+ {
+ return false;
+ }
}
else
{
