On Fri, Mar 03, 2017 at 09:21:55AM +0100, Richard Biener wrote:
> > --- gcc/gimple-fold.c.jj 2017-02-07 16:40:45.000000000 +0100
> > +++ gcc/gimple-fold.c 2017-03-02 16:04:51.304850077 +0100
> > @@ -3533,6 +3533,8 @@ fold_builtin_atomic_compare_exchange (gi
> > tree itype = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (parmt)));
> > tree ctype = build_complex_type (itype);
> > tree expected = TREE_OPERAND (gimple_call_arg (stmt, 1), 0);
> > + bool may_throw = false;
> > + edge e = NULL;
> > gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (expected)),
> > expected);
> > gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > @@ -3558,19 +3560,43 @@ fold_builtin_atomic_compare_exchange (gi
> > gimple_set_vdef (g, gimple_vdef (stmt));
> > gimple_set_vuse (g, gimple_vuse (stmt));
> > SSA_NAME_DEF_STMT (gimple_vdef (g)) = g;
> > - if (gimple_call_lhs (stmt))
> > + tree oldlhs = gimple_call_lhs (stmt);
> > + if (flag_non_call_exceptions && stmt_ends_bb_p (stmt))
>
> I think a more appropriate check is stmt_can_throw_internal (stmt)
Ok. I suppose without "flag_non_call_exceptions && ".
> > {
> > - gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > + may_throw = true;
>
> and 'throws' rather than 'may_throw'.
Ack.
> > + gimple_call_set_lhs (stmt, NULL_TREE);
> > + gsi_replace (gsi, g, true);
> > + e = find_fallthru_edge (gsi_bb (*gsi)->succs);
> > + }
> > + gimple_call_set_nothrow (as_a <gcall *> (g), flag_non_call_exceptions ==
> > 0);
>
> it should copy nothrow state from the source(s) of the folding if you
> consider flag_non_call_exceptions == true in this fn but working on
> inlined code from a flag_non_call_exceptions == false function. At least
> for calls in the source(s) that works, for other stmts I think we do
> not have an explicit nothrow on the stmt.
So just
gimple_call_set_nothrow (as_a <gcall *> (g), !throws);
then?
> > + if (oldlhs)
> > + {
> > + if (!may_throw)
> > + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > g = gimple_build_assign (make_ssa_name (itype), IMAGPART_EXPR,
> > build1 (IMAGPART_EXPR, itype, lhs));
> > - gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > - g = gimple_build_assign (gimple_call_lhs (stmt), NOP_EXPR,
> > - gimple_assign_lhs (g));
> > + if (may_throw)
> > + {
> > + gsi_insert_on_edge_immediate (e, g);
> > + *gsi = gsi_for_stmt (g);
> > + }
> > + else
> > + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > + g = gimple_build_assign (oldlhs, NOP_EXPR, gimple_assign_lhs (g));
> > + if (may_throw)
> > + gsi_insert_after (gsi, g, GSI_NEW_STMT);
> > }
> > - gsi_replace (gsi, g, true);
> > + if (!may_throw)
> > + gsi_replace (gsi, g, true);
> > g = gimple_build_assign (make_ssa_name (itype), REALPART_EXPR,
> > build1 (REALPART_EXPR, itype, lhs));
> > - gsi_insert_after (gsi, g, GSI_NEW_STMT);
> > + if (may_throw && oldlhs == NULL_TREE)
> > + {
> > + gsi_insert_on_edge_immediate (e, g);
> > + *gsi = gsi_for_stmt (g);
> > + }
> > + else
> > + gsi_insert_after (gsi, g, GSI_NEW_STMT);
>
> rather than these dances with if (may_throw) isn't it easier to
> compute an insert gsi after finding the fallthru edge, splitting
> the edge if it is a critical one? (basically doing a less
> fancy gimple_find_edge_insert_loc)
I can't see how that could simplify the code, gimple_find_edge_insert_loc
is lots of code, not exported and can return ins_after/!ins_after which
afterwards needs to be honored.
I've simplified the code a little bit by doing gsi_replace early, then
the difference is pretty much just:
- gsi_insert_after (gsi, g, GSI_NEW_STMT);
+ if (throws)
+ {
+ gsi_insert_on_edge_immediate (e, g);
+ *gsi = gsi_for_stmt (g);
+ }
+ else
+ gsi_insert_after (gsi, g, GSI_NEW_STMT);
that has to be done on the first insertion after the call (which
unfortunately means two locations). Another option I see is to
gimple_seq_add_stmt_without_update all the stmts following the call
into a seq and then conditionally insert that seq on the edge (immediate)
or insert the seq after the call. It would make sense only for
gimple-fold.c, in tree-ssa-ccp.c there is just one stmt added this way,
the debug stmt needs extra care.
2017-03-03 Jakub Jelinek <ja...@redhat.com>
PR middle-end/79805
* internal-fn.def (ATOMIC_BIT_TEST_AND_SET, ATOMIC_BIT_TEST_AND_RESET,
ATOMIC_BIT_TEST_AND_COMPLEMENT, ATOMIC_COMPARE_EXCHANGE): Remove
ECF_NOTHROW.
* gimple-fold.c (fold_builtin_atomic_compare_exchange): Set
gimple_call_nothrow_p flag based on whether original builtin can throw.
If it can, emit following stmts on the fallthrough edge.
* tree-ssa-ccp.c (optimize_atomic_bit_test_and): Similarly, except
don't create new bb if inserting just debug stmts on the edge, try to
insert them on the fallthru bb or just reset debug stmts.
* g++.dg/opt/pr79805.C: New test.
--- gcc/internal-fn.def.jj 2017-03-02 16:41:12.723121784 +0100
+++ gcc/internal-fn.def 2017-03-03 11:48:58.225451010 +0100
@@ -205,11 +205,13 @@ DEF_INTERNAL_FN (GOACC_TILE, ECF_NOTHROW
current target. */
DEF_INTERNAL_FN (SET_EDOM, ECF_LEAF | ECF_NOTHROW, NULL)
-/* Atomic functions. */
-DEF_INTERNAL_FN (ATOMIC_BIT_TEST_AND_SET, ECF_LEAF | ECF_NOTHROW, NULL)
-DEF_INTERNAL_FN (ATOMIC_BIT_TEST_AND_COMPLEMENT, ECF_LEAF | ECF_NOTHROW, NULL)
-DEF_INTERNAL_FN (ATOMIC_BIT_TEST_AND_RESET, ECF_LEAF | ECF_NOTHROW, NULL)
-DEF_INTERNAL_FN (ATOMIC_COMPARE_EXCHANGE, ECF_LEAF | ECF_NOTHROW, NULL)
+/* Atomic functions. These don't have ECF_NOTHROW because for
+ -fnon-call-exceptions they can throw, otherwise we set
+ gimple_call_nothrow_p on it. */
+DEF_INTERNAL_FN (ATOMIC_BIT_TEST_AND_SET, ECF_LEAF, NULL)
+DEF_INTERNAL_FN (ATOMIC_BIT_TEST_AND_COMPLEMENT, ECF_LEAF, NULL)
+DEF_INTERNAL_FN (ATOMIC_BIT_TEST_AND_RESET, ECF_LEAF, NULL)
+DEF_INTERNAL_FN (ATOMIC_COMPARE_EXCHANGE, ECF_LEAF, NULL)
/* To implement [[fallthrough]]. */
DEF_INTERNAL_FN (FALLTHROUGH, ECF_LEAF | ECF_NOTHROW, NULL)
--- gcc/gimple-fold.c.jj 2017-03-02 16:41:12.745121494 +0100
+++ gcc/gimple-fold.c 2017-03-03 11:52:59.679219649 +0100
@@ -3533,6 +3533,8 @@ fold_builtin_atomic_compare_exchange (gi
tree itype = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (parmt)));
tree ctype = build_complex_type (itype);
tree expected = TREE_OPERAND (gimple_call_arg (stmt, 1), 0);
+ bool throws = false;
+ edge e = NULL;
gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (expected)),
expected);
gsi_insert_before (gsi, g, GSI_SAME_STMT);
@@ -3558,19 +3560,38 @@ fold_builtin_atomic_compare_exchange (gi
gimple_set_vdef (g, gimple_vdef (stmt));
gimple_set_vuse (g, gimple_vuse (stmt));
SSA_NAME_DEF_STMT (gimple_vdef (g)) = g;
- if (gimple_call_lhs (stmt))
+ tree oldlhs = gimple_call_lhs (stmt);
+ if (stmt_can_throw_internal (stmt))
+ {
+ throws = true;
+ e = find_fallthru_edge (gsi_bb (*gsi)->succs);
+ }
+ gimple_call_set_nothrow (as_a <gcall *> (g), !throws);
+ gimple_call_set_lhs (stmt, NULL_TREE);
+ gsi_replace (gsi, g, true);
+ if (oldlhs)
{
- gsi_insert_before (gsi, g, GSI_SAME_STMT);
g = gimple_build_assign (make_ssa_name (itype), IMAGPART_EXPR,
build1 (IMAGPART_EXPR, itype, lhs));
- gsi_insert_before (gsi, g, GSI_SAME_STMT);
- g = gimple_build_assign (gimple_call_lhs (stmt), NOP_EXPR,
- gimple_assign_lhs (g));
+ if (throws)
+ {
+ gsi_insert_on_edge_immediate (e, g);
+ *gsi = gsi_for_stmt (g);
+ }
+ else
+ gsi_insert_after (gsi, g, GSI_NEW_STMT);
+ g = gimple_build_assign (oldlhs, NOP_EXPR, gimple_assign_lhs (g));
+ gsi_insert_after (gsi, g, GSI_NEW_STMT);
}
- gsi_replace (gsi, g, true);
g = gimple_build_assign (make_ssa_name (itype), REALPART_EXPR,
build1 (REALPART_EXPR, itype, lhs));
- gsi_insert_after (gsi, g, GSI_NEW_STMT);
+ if (throws && oldlhs == NULL_TREE)
+ {
+ gsi_insert_on_edge_immediate (e, g);
+ *gsi = gsi_for_stmt (g);
+ }
+ else
+ gsi_insert_after (gsi, g, GSI_NEW_STMT);
if (!useless_type_conversion_p (TREE_TYPE (expected), itype))
{
g = gimple_build_assign (make_ssa_name (TREE_TYPE (expected)),
--- gcc/tree-ssa-ccp.c.jj 2017-03-02 16:41:12.686122271 +0100
+++ gcc/tree-ssa-ccp.c 2017-03-03 11:54:07.707309233 +0100
@@ -2890,9 +2890,18 @@ optimize_atomic_bit_test_and (gimple_stm
gimple_set_location (g, gimple_location (call));
gimple_set_vuse (g, gimple_vuse (call));
gimple_set_vdef (g, gimple_vdef (call));
+ bool throws = stmt_can_throw_internal (call);
+ gimple_call_set_nothrow (as_a <gcall *> (g), !throws);
SSA_NAME_DEF_STMT (gimple_vdef (call)) = g;
gimple_stmt_iterator gsi = *gsip;
gsi_insert_after (&gsi, g, GSI_NEW_STMT);
+ edge e = NULL;
+ if (throws)
+ {
+ maybe_clean_or_replace_eh_stmt (call, g);
+ if (after || (use_bool && has_debug_uses))
+ e = find_fallthru_edge (gsi_bb (gsi)->succs);
+ }
if (after)
{
/* The internal function returns the value of the specified bit
@@ -2905,23 +2914,42 @@ optimize_atomic_bit_test_and (gimple_stm
use_bool ? build_int_cst (TREE_TYPE (lhs), 1)
: mask);
new_lhs = gimple_assign_lhs (g);
- gsi_insert_after (&gsi, g, GSI_NEW_STMT);
+ if (throws)
+ {
+ gsi_insert_on_edge_immediate (e, g);
+ gsi = gsi_for_stmt (g);
+ }
+ else
+ gsi_insert_after (&gsi, g, GSI_NEW_STMT);
}
if (use_bool && has_debug_uses)
{
- tree temp = make_node (DEBUG_EXPR_DECL);
- DECL_ARTIFICIAL (temp) = 1;
- TREE_TYPE (temp) = TREE_TYPE (lhs);
- SET_DECL_MODE (temp, TYPE_MODE (TREE_TYPE (lhs)));
- tree t = build2 (LSHIFT_EXPR, TREE_TYPE (lhs), new_lhs, bit);
- g = gimple_build_debug_bind (temp, t, g);
- gsi_insert_after (&gsi, g, GSI_NEW_STMT);
+ tree temp = NULL_TREE;
+ if (!throws || after || single_pred_p (e->dest))
+ {
+ temp = make_node (DEBUG_EXPR_DECL);
+ DECL_ARTIFICIAL (temp) = 1;
+ TREE_TYPE (temp) = TREE_TYPE (lhs);
+ SET_DECL_MODE (temp, TYPE_MODE (TREE_TYPE (lhs)));
+ tree t = build2 (LSHIFT_EXPR, TREE_TYPE (lhs), new_lhs, bit);
+ g = gimple_build_debug_bind (temp, t, g);
+ if (throws && !after)
+ {
+ gsi = gsi_after_labels (e->dest);
+ gsi_insert_before (&gsi, g, GSI_SAME_STMT);
+ }
+ else
+ gsi_insert_after (&gsi, g, GSI_NEW_STMT);
+ }
FOR_EACH_IMM_USE_STMT (g, iter, use_lhs)
if (is_gimple_debug (g))
{
use_operand_p use_p;
- FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
- SET_USE (use_p, temp);
+ if (temp == NULL_TREE)
+ gimple_debug_bind_reset_value (g);
+ else
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ SET_USE (use_p, temp);
update_stmt (g);
}
}
--- gcc/testsuite/g++.dg/opt/pr79805.C.jj 2017-03-03 11:48:58.228450970
+0100
+++ gcc/testsuite/g++.dg/opt/pr79805.C 2017-03-03 11:48:58.228450970 +0100
@@ -0,0 +1,219 @@
+// PR middle-end/79805
+// { dg-do compile }
+// { dg-options "-O2 -fnon-call-exceptions" }
+
+struct A { A (); ~A (); };
+
+void bar (void);
+
+int
+f0 (int *d, int f)
+{
+ A z;
+ int e = __atomic_compare_exchange_n (d, &f, 1, 1, __ATOMIC_RELAXED,
__ATOMIC_RELAXED);
+ return e;
+}
+
+int
+f1 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ return (__sync_fetch_and_or (a, mask) & mask) != 0;
+}
+
+int
+f2 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ unsigned int t1 = __atomic_fetch_or (a, mask, __ATOMIC_RELAXED);
+ unsigned int t2 = t1 & mask;
+ return t2 != 0;
+}
+
+long int
+f3 (long int *a, int bit)
+{
+ A z;
+ unsigned long int mask = (1ul << bit);
+ return (__atomic_fetch_or (a, mask, __ATOMIC_SEQ_CST) & mask) == 0;
+}
+
+int
+f4 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 7);
+ return (__sync_fetch_and_or (a, mask) & mask) != 0;
+}
+
+int
+f5 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 13);
+ return (__atomic_fetch_or (a, mask, __ATOMIC_RELAXED) & mask) != 0;
+}
+
+int
+f6 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 0);
+ return (__atomic_fetch_or (a, mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
+
+void
+f7 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ if ((__sync_fetch_and_xor (a, mask) & mask) != 0)
+ bar ();
+}
+
+void
+f8 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ if ((__atomic_fetch_xor (a, mask, __ATOMIC_RELAXED) & mask) == 0)
+ bar ();
+}
+
+int
+f9 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ return (__atomic_fetch_xor (a, mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
+
+int
+f10 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 7);
+ return (__sync_fetch_and_xor (a, mask) & mask) != 0;
+}
+
+int
+f11 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 13);
+ return (__atomic_fetch_xor (a, mask, __ATOMIC_RELAXED) & mask) != 0;
+}
+
+int
+f12 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 0);
+ return (__atomic_fetch_xor (a, mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
+
+int
+f13 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ return (__sync_fetch_and_and (a, ~mask) & mask) != 0;
+}
+
+int
+f14 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ return (__atomic_fetch_and (a, ~mask, __ATOMIC_RELAXED) & mask) != 0;
+}
+
+int
+f15 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ return (__atomic_fetch_and (a, ~mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
+
+int
+f16 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 7);
+ return (__sync_fetch_and_and (a, ~mask) & mask) != 0;
+}
+
+int
+f17 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 13);
+ return (__atomic_fetch_and (a, ~mask, __ATOMIC_RELAXED) & mask) != 0;
+}
+
+int
+f18 (int *a)
+{
+ A z;
+ unsigned int mask = (1u << 0);
+ return (__atomic_fetch_and (a, ~mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
+
+unsigned long int
+f19 (unsigned long int *a, int bit)
+{
+ A z;
+ unsigned long int mask = (1ul << bit);
+ return (__atomic_xor_fetch (a, mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
+
+unsigned long int
+f20 (unsigned long int *a)
+{
+ A z;
+ unsigned long int mask = (1ul << 7);
+ return (__atomic_xor_fetch (a, mask, __ATOMIC_SEQ_CST) & mask) == 0;
+}
+
+int
+f21 (int *a, int bit)
+{
+ A z;
+ unsigned int mask = (1u << bit);
+ return (__sync_fetch_and_or (a, mask) & mask);
+}
+
+unsigned long int
+f22 (unsigned long int *a)
+{
+ A z;
+ unsigned long int mask = (1ul << 7);
+ return (__atomic_xor_fetch (a, mask, __ATOMIC_SEQ_CST) & mask);
+}
+
+unsigned long int
+f23 (unsigned long int *a)
+{
+ A z;
+ unsigned long int mask = (1ul << 7);
+ return (__atomic_fetch_xor (a, mask, __ATOMIC_SEQ_CST) & mask);
+}
+
+unsigned short int
+f24 (unsigned short int *a)
+{
+ A z;
+ unsigned short int mask = (1u << 7);
+ return (__sync_fetch_and_or (a, mask) & mask) != 0;
+}
+
+unsigned short int
+f25 (unsigned short int *a)
+{
+ A z;
+ unsigned short int mask = (1u << 7);
+ return (__atomic_fetch_or (a, mask, __ATOMIC_SEQ_CST) & mask) != 0;
+}
Jakub
