1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -instcombine -S | FileCheck %s
3
4; https://bugs.llvm.org/show_bug.cgi?id=38123
5
6; Pattern:
7;   x & C s>= x
8; Should be transformed into:
9;   x s<= C
10; Iff: isPowerOf2(C + 1)
11; C must not be -1, but may be 0.
12
13; ============================================================================ ;
14; Basic positive tests
15; ============================================================================ ;
16
17define i1 @p0(i8 %x) {
18; CHECK-LABEL: @p0(
19; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i8 [[X:%.*]], 4
20; CHECK-NEXT:    ret i1 [[TMP1]]
21;
22  %tmp0 = and i8 %x, 3
23  %ret = icmp sge i8 %tmp0, %x
24  ret i1 %ret
25}
26
27; ============================================================================ ;
28; Vector tests
29; ============================================================================ ;
30
31define <2 x i1> @p1_vec_splat(<2 x i8> %x) {
32; CHECK-LABEL: @p1_vec_splat(
33; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i8> [[X:%.*]], <i8 4, i8 4>
34; CHECK-NEXT:    ret <2 x i1> [[TMP1]]
35;
36  %tmp0 = and <2 x i8> %x, <i8 3, i8 3>
37  %ret = icmp sge <2 x i8> %tmp0, %x
38  ret <2 x i1> %ret
39}
40
41define <2 x i1> @p2_vec_nonsplat(<2 x i8> %x) {
42; CHECK-LABEL: @p2_vec_nonsplat(
43; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i8> [[X:%.*]], <i8 4, i8 16>
44; CHECK-NEXT:    ret <2 x i1> [[TMP1]]
45;
46  %tmp0 = and <2 x i8> %x, <i8 3, i8 15> ; doesn't have to be splat.
47  %ret = icmp sge <2 x i8> %tmp0, %x
48  ret <2 x i1> %ret
49}
50
51define <2 x i1> @p2_vec_nonsplat_edgecase(<2 x i8> %x) {
52; CHECK-LABEL: @p2_vec_nonsplat_edgecase(
53; CHECK-NEXT:    [[TMP0:%.*]] = and <2 x i8> [[X:%.*]], <i8 3, i8 0>
54; CHECK-NEXT:    [[RET:%.*]] = icmp sge <2 x i8> [[TMP0]], [[X]]
55; CHECK-NEXT:    ret <2 x i1> [[RET]]
56;
57  %tmp0 = and <2 x i8> %x, <i8 3, i8 0>
58  %ret = icmp sge <2 x i8> %tmp0, %x
59  ret <2 x i1> %ret
60}
61
62define <3 x i1> @p3_vec_splat_undef(<3 x i8> %x) {
63; CHECK-LABEL: @p3_vec_splat_undef(
64; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <3 x i8> [[X:%.*]], <i8 4, i8 4, i8 4>
65; CHECK-NEXT:    ret <3 x i1> [[TMP1]]
66;
67  %tmp0 = and <3 x i8> %x, <i8 3, i8 undef, i8 3>
68  %ret = icmp sge <3 x i8> %tmp0, %x
69  ret <3 x i1> %ret
70}
71
72; ============================================================================ ;
73; One-use tests. We don't care about multi-uses here.
74; ============================================================================ ;
75
76declare void @use8(i8)
77
78define i1 @oneuse0(i8 %x) {
79; CHECK-LABEL: @oneuse0(
80; CHECK-NEXT:    [[TMP0:%.*]] = and i8 [[X:%.*]], 3
81; CHECK-NEXT:    call void @use8(i8 [[TMP0]])
82; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i8 [[X]], 4
83; CHECK-NEXT:    ret i1 [[TMP1]]
84;
85  %tmp0 = and i8 %x, 3
86  call void @use8(i8 %tmp0)
87  %ret = icmp sge i8 %tmp0, %x
88  ret i1 %ret
89}
90
91; ============================================================================ ;
92; Negative tests
93; ============================================================================ ;
94
95; Commutativity tests.
96
97declare i8 @gen8()
98
99define i1 @c0() {
100; CHECK-LABEL: @c0(
101; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
102; CHECK-NEXT:    [[TMP0:%.*]] = and i8 [[X]], 3
103; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[X]], [[TMP0]]
104; CHECK-NEXT:    ret i1 [[RET]]
105;
106  %x = call i8 @gen8()
107  %tmp0 = and i8 %x, 3
108  %ret = icmp sge i8 %x, %tmp0 ; swapped order
109  ret i1 %ret
110}
111
112; ============================================================================ ;
113; Rest of negative tests
114; ============================================================================ ;
115
116define i1 @n0(i8 %x) {
117; CHECK-LABEL: @n0(
118; CHECK-NEXT:    [[TMP0:%.*]] = and i8 [[X:%.*]], 4
119; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[TMP0]], [[X]]
120; CHECK-NEXT:    ret i1 [[RET]]
121;
122  %tmp0 = and i8 %x, 4 ; power-of-two, but invalid.
123  %ret = icmp sge i8 %tmp0, %x
124  ret i1 %ret
125}
126
127define i1 @n1(i8 %x, i8 %y, i8 %notx) {
128; CHECK-LABEL: @n1(
129; CHECK-NEXT:    [[TMP0:%.*]] = and i8 [[X:%.*]], 3
130; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[TMP0]], [[NOTX:%.*]]
131; CHECK-NEXT:    ret i1 [[RET]]
132;
133  %tmp0 = and i8 %x, 3
134  %ret = icmp sge i8 %tmp0, %notx ; not %x
135  ret i1 %ret
136}
137
138define <2 x i1> @n2(<2 x i8> %x) {
139; CHECK-LABEL: @n2(
140; CHECK-NEXT:    [[TMP0:%.*]] = and <2 x i8> [[X:%.*]], <i8 3, i8 16>
141; CHECK-NEXT:    [[RET:%.*]] = icmp sge <2 x i8> [[TMP0]], [[X]]
142; CHECK-NEXT:    ret <2 x i1> [[RET]]
143;
144  %tmp0 = and <2 x i8> %x, <i8 3, i8 16> ; only the first one is valid.
145  %ret = icmp sge <2 x i8> %tmp0, %x
146  ret <2 x i1> %ret
147}
148
149; ============================================================================ ;
150; Potential miscompiles.
151; ============================================================================ ;
152
153define i1 @nv(i8 %x, i8 %y) {
154; CHECK-LABEL: @nv(
155; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
156; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[TMP0]], [[X:%.*]]
157; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[TMP1]], [[X]]
158; CHECK-NEXT:    ret i1 [[RET]]
159;
160  %tmp0 = lshr i8 -1, %y
161  %tmp1 = and i8 %tmp0, %x
162  %ret = icmp sge i8 %tmp1, %x
163  ret i1 %ret
164}
165
166define <2 x i1> @n3_vec(<2 x i8> %x) {
167; CHECK-LABEL: @n3_vec(
168; CHECK-NEXT:    [[TMP0:%.*]] = and <2 x i8> [[X:%.*]], <i8 3, i8 -1>
169; CHECK-NEXT:    [[RET:%.*]] = icmp sge <2 x i8> [[TMP0]], [[X]]
170; CHECK-NEXT:    ret <2 x i1> [[RET]]
171;
172  %tmp0 = and <2 x i8> %x, <i8 3, i8 -1>
173  %ret = icmp sge <2 x i8> %tmp0, %x
174  ret <2 x i1> %ret
175}
176
177define <3 x i1> @n4_vec(<3 x i8> %x) {
178; CHECK-LABEL: @n4_vec(
179; CHECK-NEXT:    [[TMP0:%.*]] = and <3 x i8> [[X:%.*]], <i8 3, i8 undef, i8 -1>
180; CHECK-NEXT:    [[RET:%.*]] = icmp sge <3 x i8> [[TMP0]], [[X]]
181; CHECK-NEXT:    ret <3 x i1> [[RET]]
182;
183  %tmp0 = and <3 x i8> %x, <i8 3, i8 undef, i8 -1>
184  %ret = icmp sge <3 x i8> %tmp0, %x
185  ret <3 x i1> %ret
186}
187
188; Commutativity tests with variable
189
190define i1 @cv0(i8 %y) {
191; CHECK-LABEL: @cv0(
192; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
193; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
194; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], [[TMP0]]
195; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[TMP1]], [[X]]
196; CHECK-NEXT:    ret i1 [[RET]]
197;
198  %x = call i8 @gen8()
199  %tmp0 = lshr i8 -1, %y
200  %tmp1 = and i8 %x, %tmp0 ; swapped order
201  %ret = icmp sge i8 %tmp1, %x
202  ret i1 %ret
203}
204
205define i1 @cv1(i8 %y) {
206; CHECK-LABEL: @cv1(
207; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
208; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
209; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[TMP0]], [[X]]
210; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[X]], [[TMP1]]
211; CHECK-NEXT:    ret i1 [[RET]]
212;
213  %x = call i8 @gen8()
214  %tmp0 = lshr i8 -1, %y
215  %tmp1 = and i8 %tmp0, %x
216  %ret = icmp sge i8 %x, %tmp1 ; swapped order
217  ret i1 %ret
218}
219
220define i1 @cv2(i8 %y) {
221; CHECK-LABEL: @cv2(
222; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
223; CHECK-NEXT:    [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]]
224; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], [[TMP0]]
225; CHECK-NEXT:    [[RET:%.*]] = icmp sge i8 [[X]], [[TMP1]]
226; CHECK-NEXT:    ret i1 [[RET]]
227;
228  %x = call i8 @gen8()
229  %tmp0 = lshr i8 -1, %y
230  %tmp1 = and i8 %x, %tmp0 ; swapped order
231  %ret = icmp sge i8 %x, %tmp1 ; swapped order
232  ret i1 %ret
233}
234