1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
From 6684509e81e4341675c73a7dc853180229a8abcb Mon Sep 17 00:00:00 2001
From: Pronin Alexander 00812787 <pronin.alexander@huawei.com>
Date: Tue, 24 Jan 2023 16:43:40 +0300
Subject: [PATCH 04/18] Add option to allow matching uaddsub overflow for widen
ops too.
---
gcc/common.opt | 5 ++
gcc/testsuite/gcc.dg/uaddsub.c | 143 +++++++++++++++++++++++++++++++++
gcc/tree-ssa-math-opts.cc | 43 ++++++++--
3 files changed, 184 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/uaddsub.c
diff --git a/gcc/common.opt b/gcc/common.opt
index dac477c04..39c90604e 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -3106,6 +3106,11 @@ freciprocal-math
Common Var(flag_reciprocal_math) SetByCombined Optimization
Same as -fassociative-math for expressions which include division.
+fuaddsub-overflow-match-all
+Common Var(flag_uaddsub_overflow_match_all)
+Match unsigned add/sub overflow even if the target does not support
+the corresponding instruction.
+
; Nonzero means that unsafe floating-point math optimizations are allowed
; for the sake of speed. IEEE compliance is not guaranteed, and operations
; are allowed to assume that their arguments and results are "normal"
diff --git a/gcc/testsuite/gcc.dg/uaddsub.c b/gcc/testsuite/gcc.dg/uaddsub.c
new file mode 100644
index 000000000..96c26d308
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/uaddsub.c
@@ -0,0 +1,143 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fuaddsub-overflow-match-all -fdump-tree-optimized" } */
+#include <stdint.h>
+
+typedef unsigned __int128 uint128_t;
+typedef struct uint256_t
+{
+ uint128_t lo;
+ uint128_t hi;
+} uint256_t;
+
+uint16_t add16 (uint8_t a, uint8_t b)
+{
+ uint8_t tmp = a + b;
+ uint8_t overflow = 0;
+ if (tmp < a)
+ overflow = 1;
+
+ uint16_t res = overflow;
+ res <<= 8;
+ res += tmp;
+ return res;
+}
+
+uint32_t add32 (uint16_t a, uint16_t b)
+{
+ uint16_t tmp = a + b;
+ uint16_t overflow = 0;
+ if (tmp < a)
+ overflow = 1;
+
+ uint32_t res = overflow;
+ res <<= 16;
+ res += tmp;
+ return res;
+}
+
+uint64_t add64 (uint32_t a, uint32_t b)
+{
+ uint32_t tmp = a + b;
+ uint32_t overflow = 0;
+ if (tmp < a)
+ overflow = 1;
+
+ uint64_t res = overflow;
+ res <<= 32;
+ res += tmp;
+ return res;
+}
+
+uint128_t add128 (uint64_t a, uint64_t b)
+{
+ uint64_t tmp = a + b;
+ uint64_t overflow = 0;
+ if (tmp < a)
+ overflow = 1;
+
+ uint128_t res = overflow;
+ res <<= 64;
+ res += tmp;
+ return res;
+}
+
+uint256_t add256 (uint128_t a, uint128_t b)
+{
+ uint128_t tmp = a + b;
+ uint128_t overflow = 0;
+ if (tmp < a)
+ overflow = 1;
+
+ uint256_t res;
+ res.hi = overflow;
+ res.lo = tmp;
+ return res;
+}
+
+uint16_t sub16 (uint8_t a, uint8_t b)
+{
+ uint8_t tmp = a - b;
+ uint8_t overflow = 0;
+ if (tmp > a)
+ overflow = -1;
+
+ uint16_t res = overflow;
+ res <<= 8;
+ res += tmp;
+ return res;
+}
+
+uint32_t sub32 (uint16_t a, uint16_t b)
+{
+ uint16_t tmp = a - b;
+ uint16_t overflow = 0;
+ if (tmp > a)
+ overflow = -1;
+
+ uint32_t res = overflow;
+ res <<= 16;
+ res += tmp;
+ return res;
+}
+
+uint64_t sub64 (uint32_t a, uint32_t b)
+{
+ uint32_t tmp = a - b;
+ uint32_t overflow = 0;
+ if (tmp > a)
+ overflow = -1;
+
+ uint64_t res = overflow;
+ res <<= 32;
+ res += tmp;
+ return res;
+}
+
+uint128_t sub128 (uint64_t a, uint64_t b)
+{
+ uint64_t tmp = a - b;
+ uint64_t overflow = 0;
+ if (tmp > a)
+ overflow = -1;
+
+ uint128_t res = overflow;
+ res <<= 64;
+ res += tmp;
+ return res;
+}
+
+uint256_t sub256 (uint128_t a, uint128_t b)
+{
+ uint128_t tmp = a - b;
+ uint128_t overflow = 0;
+ if (tmp > a)
+ overflow = -1;
+
+ uint256_t res;
+ res.hi = overflow;
+ res.lo = tmp;
+ return res;
+}
+
+/* { dg-final { scan-tree-dump-times "= .ADD_OVERFLOW \\(a_\[0-9\]+\\(D\\), b_\[0-9\]+\\(D\\)\\)" 5 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "= .SUB_OVERFLOW \\(a_\[0-9\]+\\(D\\), b_\[0-9\]+\\(D\\)\\)" 5 "optimized" } } */
diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index 232e903b0..55d6ee8ae 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -3468,6 +3468,27 @@ convert_mult_to_fma (gimple *mul_stmt, tree op1, tree op2,
}
}
+/* Check if the corresponding operation has wider equivalent on the target. */
+
+static bool
+wider_optab_check_p (optab op, machine_mode mode, int unsignedp)
+{
+ machine_mode wider_mode;
+ FOR_EACH_WIDER_MODE (wider_mode, mode)
+ {
+ machine_mode next_mode;
+ if (optab_handler (op, wider_mode) != CODE_FOR_nothing
+ || (op == smul_optab
+ && GET_MODE_WIDER_MODE (wider_mode).exists (&next_mode)
+ && (find_widening_optab_handler ((unsignedp
+ ? umul_widen_optab
+ : smul_widen_optab),
+ next_mode, mode))))
+ return true;
+ }
+
+ return false;
+}
/* Helper function of match_arith_overflow. For MUL_OVERFLOW, if we have
a check for non-zero like:
@@ -3903,15 +3924,22 @@ match_arith_overflow (gimple_stmt_iterator *gsi, gimple *stmt,
|| code == MINUS_EXPR
|| code == MULT_EXPR
|| code == BIT_NOT_EXPR);
+ int unsignedp = TYPE_UNSIGNED (type);
if (!INTEGRAL_TYPE_P (type)
- || !TYPE_UNSIGNED (type)
- || has_zero_uses (lhs)
- || (code != PLUS_EXPR
- && code != MULT_EXPR
- && optab_handler (code == MINUS_EXPR ? usubv4_optab : uaddv4_optab,
- TYPE_MODE (type)) == CODE_FOR_nothing))
+ || !unsignedp
+ || has_zero_uses (lhs))
return false;
+ if (code == PLUS_EXPR || code == MINUS_EXPR)
+ {
+ machine_mode mode = TYPE_MODE (type);
+ optab op = code == PLUS_EXPR ? uaddv4_optab : usubv4_optab;
+ if (optab_handler (op, mode) == CODE_FOR_nothing
+ && (!flag_uaddsub_overflow_match_all
+ || !wider_optab_check_p (op, mode, unsignedp)))
+ return false;
+ }
+
tree rhs1 = gimple_assign_rhs1 (stmt);
tree rhs2 = gimple_assign_rhs2 (stmt);
FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
@@ -3986,7 +4014,8 @@ match_arith_overflow (gimple_stmt_iterator *gsi, gimple *stmt,
|| (code != MULT_EXPR && (code == BIT_NOT_EXPR ? use_seen : !use_seen))
|| (code == PLUS_EXPR
&& optab_handler (uaddv4_optab,
- TYPE_MODE (type)) == CODE_FOR_nothing)
+ TYPE_MODE (type)) == CODE_FOR_nothing
+ && !flag_uaddsub_overflow_match_all)
|| (code == MULT_EXPR
&& optab_handler (cast_stmt ? mulv4_optab : umulv4_optab,
TYPE_MODE (type)) == CODE_FOR_nothing))
--
2.33.0
|
