From: Pan Li <[email protected]>
This patch would like to support .SAT_SUB when one of the op
is IMM. Aka below 1-4 forms.
Form 1:
#define DEF_SAT_U_SUB_IMM_FMT_1(T, IMM) \
T __attribute__((noinline)) \
sat_u_sub_imm##IMM##_##T##_fmt_1 (T y) \
{ \
return IMM >= y ? IMM - y : 0; \
}
Form 2:
#define DEF_SAT_U_SUB_IMM_FMT_2(T, IMM) \
T __attribute__((noinline)) \
sat_u_sub_imm##IMM##_##T##_fmt_2 (T y) \
{ \
return IMM > y ? IMM - y : 0; \
}
Form 3:
#define DEF_SAT_U_SUB_IMM_FMT_3(T, IMM) \
T __attribute__((noinline)) \
sat_u_sub_imm##IMM##_##T##_fmt_3 (T x) \
{ \
return x >= IMM ? x - IMM : 0; \
}
Form 4:
#define DEF_SAT_U_SUB_IMM_FMT_4(T, IMM) \
T __attribute__((noinline)) \
sat_u_sub_imm##IMM##_##T##_fmt_4 (T x) \
{ \
return x > IMM ? x - IMM : 0; \
}
Take below form 1 as example:
DEF_SAT_U_SUB_OP0_IMM_FMT_1(uint32_t, 11)
Before this patch:
4 │ __attribute__((noinline))
5 │ uint64_t sat_u_sub_imm11_uint64_t_fmt_1 (uint64_t y)
6 │ {
7 │ uint64_t _1;
8 │ uint64_t _3;
9 │
10 │ ;; basic block 2, loop depth 0
11 │ ;; pred: ENTRY
12 │ if (y_2(D) <= 11)
13 │ goto <bb 3>; [50.00%]
14 │ else
15 │ goto <bb 4>; [50.00%]
16 │ ;; succ: 3
17 │ ;; 4
18 │
19 │ ;; basic block 3, loop depth 0
20 │ ;; pred: 2
21 │ _3 = 11 - y_2(D);
22 │ ;; succ: 4
23 │
24 │ ;; basic block 4, loop depth 0
25 │ ;; pred: 2
26 │ ;; 3
27 │ # _1 = PHI <0(2), _3(3)>
28 │ return _1;
29 │ ;; succ: EXIT
30 │
31 │ }
After this patch:
4 │ __attribute__((noinline))
5 │ uint64_t sat_u_sub_imm11_uint64_t_fmt_1 (uint64_t y)
6 │ {
7 │ uint64_t _1;
8 │
9 │ ;; basic block 2, loop depth 0
10 │ ;; pred: ENTRY
11 │ _1 = .SAT_SUB (11, y_2(D)); [tail call]
12 │ return _1;
13 │ ;; succ: EXIT
14 │
15 │ }
The below test suites are passed for this patch:
1. The rv64gcv fully regression tests.
2. The x86 bootstrap tests.
3. The x86 fully regression tests.
gcc/ChangeLog:
* match.pd: Add case 9 and case 10 for .SAT_SUB when one
of the op is IMM.
Signed-off-by: Pan Li <[email protected]>
---
gcc/match.pd | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/gcc/match.pd b/gcc/match.pd
index cf359b0ec0f..b2e7d61790d 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3234,6 +3234,41 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
+/* Unsigned saturation sub with op_0 imm, case 9 (branch with gt):
+ SAT_U_SUB = IMM > Y ? (IMM - Y) : 0.
+ = IMM >= Y ? (IMM - Y) : 0. */
+(match (unsigned_integer_sat_sub @0 @1)
+ (cond^ (le @1 INTEGER_CST@2) (minus INTEGER_CST@0 @1) integer_zerop)
+ (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
+ && types_match (type, @1))
+ (with
+ {
+ unsigned precision = TYPE_PRECISION (type);
+ wide_int max = wi::mask (precision, false, precision);
+ wide_int c0 = wi::to_wide (@0);
+ wide_int c2 = wi::to_wide (@2);
+ wide_int c2_add_1 = wi::add (c2, wi::uhwi (1, precision));
+ bool equal_p = wi::eq_p (c0, c2);
+ bool less_than_1_p = !wi::eq_p (c2, max) && wi::eq_p (c2_add_1, c0);
+ }
+ (if (equal_p || less_than_1_p)))))
+
+/* Unsigned saturation sub with op_1 imm, case 10:
+ SAT_U_SUB = X > IMM ? (X - IMM) : 0.
+ = X >= IMM ? (X - IMM) : 0. */
+(match (unsigned_integer_sat_sub @0 @1)
+ (plus (max @0 INTEGER_CST@1) INTEGER_CST@2)
+ (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
+ && types_match (type, @1))
+ (with
+ {
+ unsigned precision = TYPE_PRECISION (type);
+ wide_int c1 = wi::to_wide (@1);
+ wide_int c2 = wi::to_wide (@2);
+ wide_int sum = wi::add (c1, c2);
+ }
+ (if (wi::eq_p (sum, wi::uhwi (0, precision)))))))
+
/* Unsigned saturation truncate, case 1, sizeof (WT) > sizeof (NT).
SAT_U_TRUNC = (NT)x | (NT)(-(X > (WT)(NT)(-1))). */
(match (unsigned_integer_sat_trunc @0)
--
2.34.1
