From: Pan Li <[email protected]>
This patch would like to support the form 1 of the scalar signed
integer .SAT_ADD. Aka below example:
Form 1:
#define DEF_SAT_S_ADD_FMT_1(T) \
T __attribute__((noinline)) \
sat_s_add_##T##_fmt_1 (T x, T y) \
{ \
T min = (T)1u << (sizeof (T) * 8 - 1); \
T max = min - 1; \
return (x ^ y) < 0 \
? (T)(x + y) \
: ((T)(x + y) ^ x) >= 0 \
? (T)(x + y) \
: x < 0 ? min : max; \
}
DEF_SAT_S_ADD_FMT_1 (int64_t)
We can tell the difference before and after this patch if backend
implemented the ssadd<m>3 pattern similar as below.
Before this patch:
4 │ __attribute__((noinline))
5 │ int64_t sat_s_add_int64_t_fmt_1 (int64_t x, int64_t y)
6 │ {
7 │ long int _1;
8 │ long int _2;
9 │ long int _3;
10 │ int64_t _4;
11 │ long int _7;
12 │ _Bool _9;
13 │ long int _10;
14 │ long int _11;
15 │ long int _12;
16 │ long int _13;
17 │
18 │ ;; basic block 2, loop depth 0
19 │ ;; pred: ENTRY
20 │ _1 = x_5(D) ^ y_6(D);
21 │ _13 = x_5(D) + y_6(D);
22 │ _3 = x_5(D) ^ _13;
23 │ _2 = ~_1;
24 │ _7 = _2 & _3;
25 │ if (_7 >= 0)
26 │ goto <bb 4>; [59.00%]
27 │ else
28 │ goto <bb 3>; [41.00%]
29 │ ;; succ: 4
30 │ ;; 3
31 │
32 │ ;; basic block 3, loop depth 0
33 │ ;; pred: 2
34 │ _9 = x_5(D) < 0;
35 │ _10 = (long int) _9;
36 │ _11 = -_10;
37 │ _12 = _11 ^ 9223372036854775807;
38 │ ;; succ: 4
39 │
40 │ ;; basic block 4, loop depth 0
41 │ ;; pred: 2
42 │ ;; 3
43 │ # _4 = PHI <_13(2), _12(3)>
44 │ return _4;
45 │ ;; succ: EXIT
46 │
47 │ }
After this patch:
4 │ __attribute__((noinline))
5 │ int64_t sat_s_add_int64_t_fmt_1 (int64_t x, int64_t y)
6 │ {
7 │ int64_t _4;
8 │
9 │ ;; basic block 2, loop depth 0
10 │ ;; pred: ENTRY
11 │ _4 = .SAT_ADD (x_5(D), y_6(D)); [tail call]
12 │ return _4;
13 │ ;; succ: EXIT
14 │
15 │ }
The below test suites are passed for this patch.
* The rv64gcv fully regression test.
* The x86 bootstrap test.
* The x86 fully regression test.
gcc/ChangeLog:
* match.pd: Add the matching for signed .SAT_ADD.
* tree-ssa-math-opts.cc (gimple_signed_integer_sat_add): Add new
matching func decl.
(match_unsigned_saturation_add): Try signed .SAT_ADD and rename
to ...
(match_saturation_add): ... here.
(math_opts_dom_walker::after_dom_children): Update the above renamed
func from caller.
Signed-off-by: Pan Li <[email protected]>
---
gcc/match.pd | 14 +++++++++++++
gcc/tree-ssa-math-opts.cc | 42 ++++++++++++++++++++++++++++++++++-----
2 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index c9c8478d286..0a2ffc733d3 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3311,6 +3311,20 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
}
(if (otype_precision < itype_precision && wi::eq_p (trunc_max, int_cst))))))
+/* Signed saturation add, case 1:
+ T min = (T)1u << (sizeof (T) * 8 - 1);
+ T max = min - 1;
+ SAT_S_ADD = (X ^ Y) < 0
+ ? (X + Y)
+ : ((T)(X + Y) ^ X) >= 0 ? (X + Y) : X < 0 ? min : max. */
+(match (signed_integer_sat_add @0 @1)
+ (cond^ (ge (bit_and:c (bit_xor @0 (convert? @2)) (bit_not (bit_xor @0 @1)))
+ integer_zerop)
+ (convert? (plus@2 (convert1? @0) (convert1? @1)))
+ (bit_xor (negate (convert (lt @0 integer_zerop))) max_value))
+ (if (INTEGRAL_TYPE_P (type) && !TYPE_UNSIGNED (type)
+ && types_match (type, @0, @1))))
+
/* x > y && x != XXX_MIN --> x > y
x > y && x == XXX_MIN --> false . */
(for eqne (eq ne)
diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index 8d96a4c964b..d5c9b475f72 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -4023,6 +4023,8 @@ extern bool gimple_unsigned_integer_sat_add (tree, tree*,
tree (*)(tree));
extern bool gimple_unsigned_integer_sat_sub (tree, tree*, tree (*)(tree));
extern bool gimple_unsigned_integer_sat_trunc (tree, tree*, tree (*)(tree));
+extern bool gimple_signed_integer_sat_add (tree, tree*, tree (*)(tree));
+
static void
build_saturation_binary_arith_call (gimple_stmt_iterator *gsi, internal_fn fn,
tree lhs, tree op_0, tree op_1)
@@ -4072,7 +4074,8 @@ match_unsigned_saturation_add (gimple_stmt_iterator *gsi,
gassign *stmt)
}
/*
- * Try to match saturation unsigned add with PHI.
+ * Try to match saturation add with PHI.
+ * For unsigned integer:
* <bb 2> :
* _1 = x_3(D) + y_4(D);
* if (_1 >= x_3(D))
@@ -4086,10 +4089,38 @@ match_unsigned_saturation_add (gimple_stmt_iterator
*gsi, gassign *stmt)
* # _2 = PHI <255(2), _1(3)>
* =>
* <bb 4> [local count: 1073741824]:
- * _2 = .SAT_ADD (x_4(D), y_5(D)); */
+ * _2 = .SAT_ADD (x_4(D), y_5(D));
+ *
+ * For signed integer:
+ * _1 = x_5(D) ^ y_6(D);
+ * _13 = x_5(D) + y_6(D);
+ * _3 = x_5(D) ^ _13;
+ * _2 = ~_1;
+ * _7 = _2 & _3;
+ * if (_7 >= 0)
+ * goto <bb 4>; [59.00%]
+ * else
+ * goto <bb 3>; [41.00%]
+ * ;; succ: 4
+ * ;; 3
+ * ;; basic block 3, loop depth 0
+ * ;; pred: 2
+ * _9 = x_5(D) < 0;
+ * _10 = (long int) _9;
+ * _11 = -_10;
+ * _12 = _11 ^ 9223372036854775807;
+ * ;; succ: 4
+ * ;; basic block 4, loop depth 0
+ * ;; pred: 2
+ * ;; 3
+ * # _4 = PHI <_13(2), _12(3)>
+ * =>
+ * ;; basic block 2, loop depth 0
+ * ;; pred: ENTRY
+ * _4 = .SAT_ADD (x_5(D), y_6(D)); [tail call] */
static void
-match_unsigned_saturation_add (gimple_stmt_iterator *gsi, gphi *phi)
+match_saturation_add (gimple_stmt_iterator *gsi, gphi *phi)
{
if (gimple_phi_num_args (phi) != 2)
return;
@@ -4097,7 +4128,8 @@ match_unsigned_saturation_add (gimple_stmt_iterator *gsi,
gphi *phi)
tree ops[2];
tree phi_result = gimple_phi_result (phi);
- if (gimple_unsigned_integer_sat_add (phi_result, ops, NULL))
+ if (gimple_unsigned_integer_sat_add (phi_result, ops, NULL)
+ || gimple_signed_integer_sat_add (phi_result, ops, NULL))
build_saturation_binary_arith_call (gsi, phi, IFN_SAT_ADD, phi_result,
ops[0], ops[1]);
}
@@ -6097,7 +6129,7 @@ math_opts_dom_walker::after_dom_children (basic_block bb)
gsi_next (&psi))
{
gimple_stmt_iterator gsi = gsi_after_labels (bb);
- match_unsigned_saturation_add (&gsi, psi.phi ());
+ match_saturation_add (&gsi, psi.phi ());
match_unsigned_saturation_sub (&gsi, psi.phi ());
}
--
2.43.0
