https://gcc.gnu.org/g:e14afbe2d1c696cc4abda24ca10a5a43ee9c2818
commit r15-1081-ge14afbe2d1c696cc4abda24ca10a5a43ee9c2818
Author: Pan Li <pan2...@intel.com>
Date: Thu Jun 6 09:19:53 2024 +0800
Match: Support more form for scalar unsigned SAT_ADD
After we support one gassign form of the unsigned .SAT_ADD, we
would like to support more forms including both the branch and
branchless. There are 5 other forms of .SAT_ADD, list as below:
Form 1:
#define SAT_ADD_U_1(T) \
T sat_add_u_1_##T(T x, T y) \
{ \
return (T)(x + y) >= x ? (x + y) : -1; \
}
Form 2:
#define SAT_ADD_U_2(T) \
T sat_add_u_2_##T(T x, T y) \
{ \
T ret; \
T overflow = __builtin_add_overflow (x, y, &ret); \
return (T)(-overflow) | ret; \
}
Form 3:
#define SAT_ADD_U_3(T) \
T sat_add_u_3_##T (T x, T y) \
{ \
T ret; \
return __builtin_add_overflow (x, y, &ret) ? -1 : ret; \
}
Form 4:
#define SAT_ADD_U_4(T) \
T sat_add_u_4_##T (T x, T y) \
{ \
T ret; \
return __builtin_add_overflow (x, y, &ret) == 0 ? ret : -1; \
}
Form 5:
#define SAT_ADD_U_5(T) \
T sat_add_u_5_##T(T x, T y) \
{ \
return (T)(x + y) < x ? -1 : (x + y); \
}
Take the forms 3 of above as example:
uint64_t
sat_add (uint64_t x, uint64_t y)
{
uint64_t ret;
return __builtin_add_overflow (x, y, &ret) ? -1 : ret;
}
Before this patch:
uint64_t sat_add (uint64_t x, uint64_t y)
{
long unsigned int _1;
long unsigned int _2;
uint64_t _3;
__complex__ long unsigned int _6;
;; basic block 2, loop depth 0
;; pred: ENTRY
_6 = .ADD_OVERFLOW (x_4(D), y_5(D));
_2 = IMAGPART_EXPR <_6>;
if (_2 != 0)
goto <bb 4>; [35.00%]
else
goto <bb 3>; [65.00%]
;; succ: 4
;; 3
;; basic block 3, loop depth 0
;; pred: 2
_1 = REALPART_EXPR <_6>;
;; succ: 4
;; basic block 4, loop depth 0
;; pred: 3
;; 2
# _3 = PHI <_1(3), 18446744073709551615(2)>
return _3;
;; succ: EXIT
}
After this patch:
uint64_t sat_add (uint64_t x, uint64_t y)
{
long unsigned int _12;
;; basic block 2, loop depth 0
;; pred: ENTRY
_12 = .SAT_ADD (x_4(D), y_5(D)); [tail call]
return _12;
;; succ: EXIT
}
The flag '^' acts on cond_expr will generate matching code similar as below:
else if (gphi *_a1 = dyn_cast <gphi *> (_d1))
{
basic_block _b1 = gimple_bb (_a1);
if (gimple_phi_num_args (_a1) == 2)
{
basic_block _pb_0_1 = EDGE_PRED (_b1, 0)->src;
basic_block _pb_1_1 = EDGE_PRED (_b1, 1)->src;
basic_block _db_1 = safe_dyn_cast <gcond *> (*gsi_last_bb (_pb_0_1))
? _pb_0_1 : _pb_1_1;
basic_block _other_db_1 = safe_dyn_cast <gcond *> (*gsi_last_bb
(_pb_0_1))
? _pb_1_1 : _pb_0_1;
gcond *_ct_1 = safe_dyn_cast <gcond *> (*gsi_last_bb (_db_1));
if (_ct_1 && EDGE_COUNT (_other_db_1->preds) == 1
&& EDGE_COUNT (_other_db_1->succs) == 1
&& EDGE_PRED (_other_db_1, 0)->src == _db_1)
{
tree _cond_lhs_1 = gimple_cond_lhs (_ct_1);
tree _cond_rhs_1 = gimple_cond_rhs (_ct_1);
tree _p0 = build2 (gimple_cond_code (_ct_1), boolean_type_node,
_cond_lhs_1, _cond_rhs_1);
bool _arg_0_is_true_1 = gimple_phi_arg_edge (_a1, 0)->flags &
EDGE_TRUE_VALUE;
tree _p1 = gimple_phi_arg_def (_a1, _arg_0_is_true_1 ? 0 : 1);
tree _p2 = gimple_phi_arg_def (_a1, _arg_0_is_true_1 ? 1 : 0);
....
The below test suites are passed for this patch.
* The x86 bootstrap test.
* The x86 fully regression test.
* The riscv fully regression test.
gcc/ChangeLog:
* doc/match-and-simplify.texi: Add doc for the matching flag '^'.
* genmatch.cc (cmp_operand): Add match_phi comparation.
(dt_node::gen_kids_1): Add cond_expr bool flag for phi match.
(dt_operand::gen_phi_on_cond): Add new func to gen phi matching
on cond_expr.
(parser::parse_expr): Add handling for the expr flag '^'.
* match.pd: Add more form for unsigned .SAT_ADD.
* tree-ssa-math-opts.cc (build_saturation_binary_arith_call): Add
new func impl to build call for phi gimple.
(match_unsigned_saturation_add): Add new func impl to match the
.SAT_ADD for phi gimple.
(math_opts_dom_walker::after_dom_children): Add phi matching
try for all gimple phi stmt.
Signed-off-by: Pan Li <pan2...@intel.com>
Diff:
---
gcc/doc/match-and-simplify.texi | 16 +++++
gcc/genmatch.cc | 126 +++++++++++++++++++++++++++++++++++++++-
gcc/match.pd | 43 +++++++++++++-
gcc/tree-ssa-math-opts.cc | 56 +++++++++++++++++-
4 files changed, 236 insertions(+), 5 deletions(-)
diff --git a/gcc/doc/match-and-simplify.texi b/gcc/doc/match-and-simplify.texi
index 01f19e2f62c..63d5af159f5 100644
--- a/gcc/doc/match-and-simplify.texi
+++ b/gcc/doc/match-and-simplify.texi
@@ -361,6 +361,22 @@ Usually the types of the generated result expressions are
determined from the context, but sometimes like in the above case
it is required that you specify them explicitly.
+Another modifier for generated expressions is @code{^} which
+tells the machinery to try more matches for some special cases.
+For example, normally the @code{cond} only allows the gimple
+assign when matching. It will also try to match the gimple @code{PHI}
+besides gimple assign if appending the @code{^} to the @code{cond}.
+Aka @code{cond^}. Consider below example
+
+@smallexample
+(match (unsigned_sat_add @@0 @@1)
+ (cond^ (ge (plus:c@@2 @@0 @@1) @@0) @@2 integer_minus_onep))
+@end smallexample
+
+The above matching will generate the predicate function named
+@code{gimple_unsigned_sat_add} that accepts both the gimple
+assign and gimple @code{PHI}.
+
Another modifier for generated expressions is @code{!} which
tells the machinery to only consider the simplification in case
the marked expression simplified to a simple operand. Consider
diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
index f1e0e7abe0c..a56bd90cb2c 100644
--- a/gcc/genmatch.cc
+++ b/gcc/genmatch.cc
@@ -848,12 +848,13 @@ public:
: operand (OP_EXPR, loc), operation (operation_),
ops (vNULL), expr_type (NULL), is_commutative (is_commutative_),
is_generic (false), force_single_use (false), force_leaf (false),
- opt_grp (0) {}
+ match_phi (false), opt_grp (0) {}
expr (expr *e)
: operand (OP_EXPR, e->location), operation (e->operation),
ops (vNULL), expr_type (e->expr_type), is_commutative
(e->is_commutative),
is_generic (e->is_generic), force_single_use (e->force_single_use),
- force_leaf (e->force_leaf), opt_grp (e->opt_grp) {}
+ force_leaf (e->force_leaf), match_phi (e->match_phi),
+ opt_grp (e->opt_grp) {}
void append_op (operand *op) { ops.safe_push (op); }
/* The operator and its operands. */
id_base *operation;
@@ -871,6 +872,8 @@ public:
/* Whether in the result expression this should be a leaf node
with any children simplified down to simple operands. */
bool force_leaf;
+ /* Whether the COND_EXPR is matching PHI gimple, default false. */
+ bool match_phi;
/* If non-zero, the group for optional handling. */
unsigned char opt_grp;
void gen_transform (FILE *f, int, const char *, bool, int,
@@ -1819,6 +1822,7 @@ public:
char *get_name (char *);
void gen_opname (char *, unsigned);
+ void gen_phi_on_cond (FILE *, int, int);
};
/* Leaf node of the decision tree, used for DT_SIMPLIFY. */
@@ -1898,7 +1902,8 @@ cmp_operand (operand *o1, operand *o2)
expr *e1 = static_cast<expr *>(o1);
expr *e2 = static_cast<expr *>(o2);
if (e1->operation != e2->operation
- || e1->is_generic != e2->is_generic)
+ || e1->is_generic != e2->is_generic
+ || e1->match_phi != e2->match_phi)
return false;
if (e1->operation->kind == id_base::FN
/* For function calls also compare number of arguments. */
@@ -3251,6 +3256,7 @@ dt_node::gen_kids_1 (FILE *f, int indent, bool gimple,
int depth,
depth);
indent += 4;
fprintf_indent (f, indent, "{\n");
+ bool cond_expr_p = false;
for (unsigned i = 0; i < exprs_len; ++i)
{
expr *e = as_a <expr *> (gimple_exprs[i]->op);
@@ -3262,6 +3268,7 @@ dt_node::gen_kids_1 (FILE *f, int indent, bool gimple,
int depth,
else
{
id_base *op = e->operation;
+ cond_expr_p |= (*op == COND_EXPR && e->match_phi);
if (*op == CONVERT_EXPR || *op == NOP_EXPR)
fprintf_indent (f, indent, "CASE_CONVERT:\n");
else
@@ -3275,6 +3282,27 @@ dt_node::gen_kids_1 (FILE *f, int indent, bool gimple,
int depth,
fprintf_indent (f, indent, "default:;\n");
fprintf_indent (f, indent, "}\n");
indent -= 4;
+
+ if (cond_expr_p)
+ {
+ fprintf_indent (f, indent,
+ "else if (gphi *_a%d = dyn_cast <gphi *> (_d%d))\n",
+ depth, depth);
+ indent += 2;
+ fprintf_indent (f, indent, "{\n");
+ indent += 2;
+
+ for (unsigned i = 0; i < exprs_len; i++)
+ {
+ expr *e = as_a <expr *> (gimple_exprs[i]->op);
+ if (*e->operation == COND_EXPR && e->match_phi)
+ gimple_exprs[i]->gen_phi_on_cond (f, indent, depth);
+ }
+
+ indent -= 2;
+ fprintf_indent (f, indent, "}\n");
+ indent -= 2;
+ }
}
if (fns_len)
@@ -3483,6 +3511,86 @@ dt_operand::gen (FILE *f, int indent, bool gimple, int
depth)
}
}
+/* Generate matching code for the phi when meet COND_EXPR. */
+
+void
+dt_operand::gen_phi_on_cond (FILE *f, int indent, int depth)
+{
+ fprintf_indent (f, indent,
+ "basic_block _b%d = gimple_bb (_a%d);\n", depth, depth);
+
+ fprintf_indent (f, indent, "if (gimple_phi_num_args (_a%d) == 2)\n", depth);
+
+ indent += 2;
+ fprintf_indent (f, indent, "{\n");
+ indent += 2;
+
+ fprintf_indent (f, indent,
+ "basic_block _pb_0_%d = EDGE_PRED (_b%d, 0)->src;\n", depth, depth);
+ fprintf_indent (f, indent,
+ "basic_block _pb_1_%d = EDGE_PRED (_b%d, 1)->src;\n", depth, depth);
+ fprintf_indent (f, indent,
+ "basic_block _db_%d = safe_dyn_cast <gcond *> (*gsi_last_bb (_pb_0_%d)) ? "
+ "_pb_0_%d : _pb_1_%d;\n", depth, depth, depth, depth);
+ fprintf_indent (f, indent,
+ "basic_block _other_db_%d = safe_dyn_cast <gcond *> "
+ "(*gsi_last_bb (_pb_0_%d)) ? _pb_1_%d : _pb_0_%d;\n",
+ depth, depth, depth, depth);
+
+ fprintf_indent (f, indent,
+ "gcond *_ct_%d = safe_dyn_cast <gcond *> (*gsi_last_bb (_db_%d));\n",
+ depth, depth);
+ fprintf_indent (f, indent, "if (_ct_%d"
+ " && EDGE_COUNT (_other_db_%d->preds) == 1\n", depth, depth);
+ fprintf_indent (f, indent,
+ " && EDGE_COUNT (_other_db_%d->succs) == 1\n", depth);
+ fprintf_indent (f, indent,
+ " && EDGE_PRED (_other_db_%d, 0)->src == _db_%d)\n", depth, depth);
+
+ indent += 2;
+ fprintf_indent (f, indent, "{\n");
+ indent += 2;
+
+ fprintf_indent (f, indent,
+ "tree _cond_lhs_%d = gimple_cond_lhs (_ct_%d);\n", depth, depth);
+ fprintf_indent (f, indent,
+ "tree _cond_rhs_%d = gimple_cond_rhs (_ct_%d);\n", depth, depth);
+
+ char opname_0[20];
+ char opname_1[20];
+ char opname_2[20];
+ gen_opname (opname_0, 0);
+
+ fprintf_indent (f, indent,
+ "tree %s = build2 (gimple_cond_code (_ct_%d), "
+ "boolean_type_node, _cond_lhs_%d, _cond_rhs_%d);\n",
+ opname_0, depth, depth, depth);
+
+ fprintf_indent (f, indent,
+ "bool _arg_0_is_true_%d = gimple_phi_arg_edge (_a%d, 0)->flags"
+ " & EDGE_TRUE_VALUE;\n", depth, depth);
+
+ gen_opname (opname_1, 1);
+ fprintf_indent (f, indent,
+ "tree %s = gimple_phi_arg_def (_a%d, _arg_0_is_true_%d ? 0 : 1);\n",
+ opname_1, depth, depth);
+
+ gen_opname (opname_2, 2);
+ fprintf_indent (f, indent,
+ "tree %s = gimple_phi_arg_def (_a%d, _arg_0_is_true_%d ? 1 : 0);\n",
+ opname_2, depth, depth);
+
+ gen_kids (f, indent, true, depth);
+
+ indent -= 2;
+ fprintf_indent (f, indent, "}\n");
+ indent -= 2;
+
+ indent -= 2;
+ fprintf_indent (f, indent, "}\n");
+ indent -= 2;
+}
+
/* Emit a logging call to the debug file to the file F, with the INDENT from
either the RESULT location or the S's match location if RESULT is null. */
static void
@@ -4600,6 +4708,18 @@ parser::parse_expr ()
e->force_leaf = true;
}
+ if (token->type == CPP_XOR && !(token->flags & PREV_WHITE))
+ {
+ if (!parsing_match_operand)
+ fatal_at (token, "modifier '^' is only valid in a match expression");
+
+ if (!(*e->operation == COND_EXPR))
+ fatal_at (token, "modifier '^' can only act on operation COND_EXPR");
+
+ eat_token (CPP_XOR);
+ e->match_phi = true;
+ }
+
if (token->type == CPP_COLON
&& !(token->flags & PREV_WHITE))
{
diff --git a/gcc/match.pd b/gcc/match.pd
index ebc60eba8dc..5cfe81e80b3 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3056,31 +3056,48 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& wi::eq_p (wi::to_wide (int_cst), wi::max_value (itype))))))
/* Unsigned Saturation Add */
+/* SAT_ADD = usadd_left_part_1 | usadd_right_part_1, aka:
+ SAT_ADD = (X + Y) | -((X + Y) < X) */
(match (usadd_left_part_1 @0 @1)
(plus:c @0 @1)
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
+/* SAT_ADD = usadd_left_part_2 | usadd_right_part_2, aka:
+ SAT_ADD = REALPART_EXPR <.ADD_OVERFLOW> | (IMAGPART_EXPR <.ADD_OVERFLOW> !=
0) */
(match (usadd_left_part_2 @0 @1)
(realpart (IFN_ADD_OVERFLOW:c @0 @1))
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
+/* SAT_ADD = usadd_left_part_1 | usadd_right_part_1, aka:
+ SAT_ADD = (X + Y) | -((type)(X + Y) < X) */
(match (usadd_right_part_1 @0 @1)
(negate (convert (lt (plus:c @0 @1) @0)))
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
+/* SAT_ADD = usadd_left_part_1 | usadd_right_part_1, aka:
+ SAT_ADD = (X + Y) | -(X > (X + Y)) */
(match (usadd_right_part_1 @0 @1)
(negate (convert (gt @0 (plus:c @0 @1))))
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
+/* SAT_ADD = usadd_left_part_2 | usadd_right_part_2, aka:
+ SAT_ADD = REALPART_EXPR <.ADD_OVERFLOW> | (IMAGPART_EXPR <.ADD_OVERFLOW> !=
0) */
(match (usadd_right_part_2 @0 @1)
(negate (convert (ne (imagpart (IFN_ADD_OVERFLOW:c @0 @1)) integer_zerop)))
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
+/* SAT_ADD = usadd_left_part_2 | usadd_right_part_2, aka:
+ SAT_ADD = REALPART_EXPR <.ADD_OVERFLOW> | -IMAGPART_EXPR <.ADD_OVERFLOW> */
+(match (usadd_right_part_2 @0 @1)
+ (negate (imagpart (IFN_ADD_OVERFLOW:c @0 @1)))
+ (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
+ && types_match (type, @0, @1))))
+
/* We cannot merge or overload usadd_left_part_1 and usadd_left_part_2
because the sub part of left_part_2 cannot work with right_part_1.
For example, left_part_2 pattern focus one .ADD_OVERFLOW but the
@@ -3092,10 +3109,34 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(match (unsigned_integer_sat_add @0 @1)
(bit_ior:c (usadd_left_part_1 @0 @1) (usadd_right_part_1 @0 @1)))
-/* Unsigned saturation add, case 2 (branchless with .ADD_OVERFLOW). */
+/* Unsigned saturation add, case 2 (branchless with .ADD_OVERFLOW):
+ SAT_ADD = REALPART_EXPR <.ADD_OVERFLOW> | -IMAGPART_EXPR <.ADD_OVERFLOW> or
+ SAT_ADD = REALPART_EXPR <.ADD_OVERFLOW> | (IMAGPART_EXPR <.ADD_OVERFLOW> !=
0) */
(match (unsigned_integer_sat_add @0 @1)
(bit_ior:c (usadd_left_part_2 @0 @1) (usadd_right_part_2 @0 @1)))
+/* Unsigned saturation add, case 3 (branch with ge):
+ SAT_U_ADD = (X + Y) >= x ? (X + Y) : -1. */
+(match (unsigned_integer_sat_add @0 @1)
+ (cond^ (ge (usadd_left_part_1@2 @0 @1) @0) @2 integer_minus_onep))
+
+/* Unsigned saturation add, case 4 (branch with lt):
+ SAT_U_ADD = (X + Y) < x ? -1 : (X + Y). */
+(match (unsigned_integer_sat_add @0 @1)
+ (cond^ (lt (usadd_left_part_1@2 @0 @1) @0) integer_minus_onep @2))
+
+/* Unsigned saturation add, case 5 (branch with eq .ADD_OVERFLOW):
+ SAT_U_ADD = REALPART_EXPR <.ADD_OVERFLOW> == 0 ? .ADD_OVERFLOW : -1. */
+(match (unsigned_integer_sat_add @0 @1)
+ (cond^ (eq (imagpart (IFN_ADD_OVERFLOW:c @0 @1)) integer_zerop)
+ (usadd_left_part_2 @0 @1) integer_minus_onep))
+
+/* Unsigned saturation add, case 6 (branch with ne .ADD_OVERFLOW):
+ SAT_U_ADD = REALPART_EXPR <.ADD_OVERFLOW> != 0 ? -1 : .ADD_OVERFLOW. */
+(match (unsigned_integer_sat_add @0 @1)
+ (cond^ (ne (imagpart (IFN_ADD_OVERFLOW:c @0 @1)) integer_zerop)
+ integer_minus_onep (usadd_left_part_2 @0 @1)))
+
/* Unsigned saturation sub, case 1 (branch with gt):
SAT_U_SUB = X > Y ? X - Y : 0 */
(match (unsigned_integer_sat_sub @0 @1)
diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index 469e34d828d..173b0366f5e 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -4101,8 +4101,24 @@ build_saturation_binary_arith_call (gimple_stmt_iterator
*gsi, internal_fn fn,
}
}
+static void
+build_saturation_binary_arith_call (gimple_stmt_iterator *gsi, gphi *phi,
+ internal_fn fn, tree lhs, tree op_0,
+ tree op_1)
+{
+ if (direct_internal_fn_supported_p (fn, TREE_TYPE (lhs), OPTIMIZE_FOR_BOTH))
+ {
+ gcall *call = gimple_build_call_internal (fn, 2, op_0, op_1);
+ gimple_call_set_lhs (call, lhs);
+ gsi_insert_before (gsi, call, GSI_SAME_STMT);
+
+ gimple_stmt_iterator psi = gsi_for_stmt (phi);
+ remove_phi_node (&psi, /* release_lhs_p */ false);
+ }
+}
+
/*
- * Try to match saturation unsigned add.
+ * Try to match saturation unsigned add with assign.
* _7 = _4 + _6;
* _8 = _4 > _7;
* _9 = (long unsigned int) _8;
@@ -4121,6 +4137,37 @@ match_unsigned_saturation_add (gimple_stmt_iterator
*gsi, gassign *stmt)
build_saturation_binary_arith_call (gsi, IFN_SAT_ADD, lhs, ops[0], ops[1]);
}
+/*
+ * Try to match saturation unsigned add with PHI.
+ * <bb 2> :
+ * _1 = x_3(D) + y_4(D);
+ * if (_1 >= x_3(D))
+ * goto <bb 3>; [INV]
+ * else
+ * goto <bb 4>; [INV]
+ *
+ * <bb 3> :
+ *
+ * <bb 4> :
+ * # _2 = PHI <255(2), _1(3)>
+ * =>
+ * <bb 4> [local count: 1073741824]:
+ * _2 = .SAT_ADD (x_4(D), y_5(D)); */
+
+static void
+match_unsigned_saturation_add (gimple_stmt_iterator *gsi, gphi *phi)
+{
+ if (gimple_phi_num_args (phi) != 2)
+ return;
+
+ tree ops[2];
+ tree phi_result = gimple_phi_result (phi);
+
+ if (gimple_unsigned_integer_sat_add (phi_result, ops, NULL))
+ build_saturation_binary_arith_call (gsi, phi, IFN_SAT_ADD, phi_result,
+ ops[0], ops[1]);
+}
+
/*
* Try to match saturation unsigned sub.
* _1 = _4 >= _5;
@@ -6052,6 +6099,13 @@ math_opts_dom_walker::after_dom_children (basic_block bb)
fma_deferring_state fma_state (param_avoid_fma_max_bits > 0);
+ for (gphi_iterator psi = gsi_start_phis (bb); !gsi_end_p (psi);
+ gsi_next (&psi))
+ {
+ gimple_stmt_iterator gsi = gsi_last_bb (bb);
+ match_unsigned_saturation_add (&gsi, psi.phi ());
+ }
+
for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi);)
{
gimple *stmt = gsi_stmt (gsi);
