https://gcc.gnu.org/g:1f84115e6569bc647a93e142ae53098efe2b8101
commit r15-4250-g1f84115e6569bc647a93e142ae53098efe2b8101
Author: Pan Li <pan2...@intel.com>
Date: Wed Oct 9 10:28:55 2024 +0800
Match: Support form 2 for scalar signed integer SAT_TRUNC
This patch would like to support the form 2 of the scalar signed
integer SAT_TRUNC. Aka below example:
Form 2:
#define DEF_SAT_S_TRUNC_FMT_2(NT, WT, NT_MIN, NT_MAX) \
NT __attribute__((noinline)) \
sat_s_trunc_##WT##_to_##NT##_fmt_2 (WT x) \
{ \
NT trunc = (NT)x; \
return (WT)NT_MIN < x && x < (WT)NT_MAX \
? trunc \
: x < 0 ? NT_MIN : NT_MAX; \
}
DEF_SAT_S_TRUNC_FMT_2(int8_t, int16_t, INT8_MIN, INT8_MAX)
Before this patch:
4 │ __attribute__((noinline))
5 │ int8_t sat_s_trunc_int16_t_to_int8_t_fmt_2 (int16_t x)
6 │ {
7 │ int8_t trunc;
8 │ unsigned short x.0_1;
9 │ unsigned short _2;
10 │ int8_t _3;
11 │ _Bool _7;
12 │ signed char _8;
13 │ signed char _9;
14 │ signed char _10;
15 │
16 │ ;; basic block 2, loop depth 0
17 │ ;; pred: ENTRY
18 │ x.0_1 = (unsigned short) x_4(D);
19 │ _2 = x.0_1 + 127;
20 │ if (_2 > 253)
21 │ goto <bb 4>; [50.00%]
22 │ else
23 │ goto <bb 3>; [50.00%]
24 │ ;; succ: 4
25 │ ;; 3
26 │
27 │ ;; basic block 3, loop depth 0
28 │ ;; pred: 2
29 │ trunc_5 = (int8_t) x_4(D);
30 │ goto <bb 5>; [100.00%]
31 │ ;; succ: 5
32 │
33 │ ;; basic block 4, loop depth 0
34 │ ;; pred: 2
35 │ _7 = x_4(D) < 0;
36 │ _8 = (signed char) _7;
37 │ _9 = -_8;
38 │ _10 = _9 ^ 127;
39 │ ;; succ: 5
40 │
41 │ ;; basic block 5, loop depth 0
42 │ ;; pred: 3
43 │ ;; 4
44 │ # _3 = PHI <trunc_5(3), _10(4)>
45 │ return _3;
46 │ ;; succ: EXIT
47 │
48 │ }
After this patch:
4 │ __attribute__((noinline))
5 │ int8_t sat_s_trunc_int16_t_to_int8_t_fmt_2 (int16_t x)
6 │ {
7 │ int8_t _3;
8 │
9 │ ;; basic block 2, loop depth 0
10 │ ;; pred: ENTRY
11 │ _3 = .SAT_TRUNC (x_4(D)); [tail call]
12 │ return _3;
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 case 2 matching pattern for signed SAT_TRUNC.
Signed-off-by: Pan Li <pan2...@intel.com>
Diff:
---
gcc/match.pd | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index 8a7569ce3871..754c1f39d8b5 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3461,7 +3461,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
}
(if (wi::eq_p (trunc_max, int_cst_1) && wi::eq_p (max, int_cst_2))))))
-/* Signed saturation truncate, case 1, sizeof (WT) > sizeof (NT).
+/* Signed saturation truncate, case 1 and case 2, sizeof (WT) > sizeof (NT).
SAT_S_TRUNC(X) = (unsigned)X + NT_MAX + 1 > Unsigned_MAX ? (NT)X. */
(match (signed_integer_sat_trunc @0)
(cond^ (gt (plus:c (convert@4 @0) INTEGER_CST@1) INTEGER_CST@2)
@@ -3471,17 +3471,22 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& !TYPE_UNSIGNED (TREE_TYPE (@0)) && TYPE_UNSIGNED (TREE_TYPE (@4)))
(with
{
- unsigned itype_precision = TYPE_PRECISION (TREE_TYPE (@0));
- unsigned otype_precision = TYPE_PRECISION (type);
- wide_int offset = wi::uhwi (HOST_WIDE_INT_1U << (otype_precision - 1),
itype_precision);
- wide_int trunc_max = wi::mask (otype_precision, false, itype_precision);
- wide_int max = wi::mask (otype_precision - 1, false, otype_precision);
+ unsigned itype_prec = TYPE_PRECISION (TREE_TYPE (@0));
+ unsigned otype_prec = TYPE_PRECISION (type);
+ wide_int offset = wi::uhwi (HOST_WIDE_INT_1U << (otype_prec - 1),
+ itype_prec); // Aka 128 for int8_t
+ wide_int limit_0 = wi::mask (otype_prec, false, itype_prec); // Aka 255
+ wide_int limit_1 = wi::uhwi ((HOST_WIDE_INT_1U << otype_prec) - 3,
+ itype_prec); // Aka 253
+ wide_int otype_max = wi::mask (otype_prec - 1, false, otype_prec);
+ wide_int itype_max = wi::mask (otype_prec - 1, false, itype_prec);
wide_int int_cst_1 = wi::to_wide (@1);
wide_int int_cst_2 = wi::to_wide (@2);
wide_int int_cst_3 = wi::to_wide (@3);
}
- (if (wi::eq_p (int_cst_1, offset) && wi::eq_p (int_cst_2, trunc_max)
- && wi::eq_p (int_cst_3, max))))))
+ (if (((wi::eq_p (int_cst_1, offset) && wi::eq_p (int_cst_2, limit_0))
+ || (wi::eq_p (int_cst_1, itype_max) && wi::eq_p (int_cst_2, limit_1)))
+ && wi::eq_p (int_cst_3, otype_max))))))
/* x > y && x != XXX_MIN --> x > y
x > y && x == XXX_MIN --> false . */
