1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -instcombine -S | FileCheck %s
3
4; If we have some pattern that leaves only some low bits set, and then performs
5; left-shift of those bits, we can combine those two shifts into a shift+mask.
6
7; There are many variants to this pattern:
8;   a)  (trunc (x & ((1 << maskNbits) - 1))) << shiftNbits
9; simplify to:
10;   ((trunc(x)) << shiftNbits) & (~(-1 << (maskNbits+shiftNbits)))
11
12; Simple tests.
13
14declare void @use32(i32)
15declare void @use64(i64)
16
17define i32 @t0_basic(i64 %x, i32 %nbits) {
18; CHECK-LABEL: @t0_basic(
19; CHECK-NEXT:    [[T0:%.*]] = add i32 [[NBITS:%.*]], -1
20; CHECK-NEXT:    [[T1:%.*]] = zext i32 [[T0]] to i64
21; CHECK-NEXT:    [[T2:%.*]] = shl i64 1, [[T1]]
22; CHECK-NEXT:    [[T3:%.*]] = add i64 [[T2]], -1
23; CHECK-NEXT:    [[T4:%.*]] = sub i32 32, [[NBITS]]
24; CHECK-NEXT:    call void @use32(i32 [[T0]])
25; CHECK-NEXT:    call void @use64(i64 [[T1]])
26; CHECK-NEXT:    call void @use64(i64 [[T2]])
27; CHECK-NEXT:    call void @use64(i64 [[T3]])
28; CHECK-NEXT:    call void @use32(i32 [[T4]])
29; CHECK-NEXT:    [[TMP1:%.*]] = trunc i64 [[X:%.*]] to i32
30; CHECK-NEXT:    [[TMP2:%.*]] = shl i32 [[TMP1]], [[T4]]
31; CHECK-NEXT:    [[T7:%.*]] = and i32 [[TMP2]], 2147483647
32; CHECK-NEXT:    ret i32 [[T7]]
33;
34  %t0 = add i32 %nbits, -1
35  %t1 = zext i32 %t0 to i64
36  %t2 = shl i64 1, %t1 ; shifting by nbits-1
37  %t3 = add i64 %t2, -1
38  %t4 = sub i32 32, %nbits
39
40  call void @use32(i32 %t0)
41  call void @use64(i64 %t1)
42  call void @use64(i64 %t2)
43  call void @use64(i64 %t3)
44  call void @use32(i32 %t4)
45
46  %t5 = and i64 %t3, %x
47  %t6 = trunc i64 %t5 to i32
48  %t7 = shl i32 %t6, %t4
49  ret i32 %t7
50}
51
52; Vectors
53
54declare void @use8xi32(<8 x i32>)
55declare void @use8xi64(<8 x i64>)
56
57define <8 x i32> @t1_vec_splat(<8 x i64> %x, <8 x i32> %nbits) {
58; CHECK-LABEL: @t1_vec_splat(
59; CHECK-NEXT:    [[T0:%.*]] = add <8 x i32> [[NBITS:%.*]], <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1>
60; CHECK-NEXT:    [[T1:%.*]] = zext <8 x i32> [[T0]] to <8 x i64>
61; CHECK-NEXT:    [[T2:%.*]] = shl <8 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1>, [[T1]]
62; CHECK-NEXT:    [[T3:%.*]] = add <8 x i64> [[T2]], <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>
63; CHECK-NEXT:    [[T4:%.*]] = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32>, [[NBITS]]
64; CHECK-NEXT:    call void @use8xi32(<8 x i32> [[T0]])
65; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T1]])
66; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T2]])
67; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T3]])
68; CHECK-NEXT:    call void @use8xi32(<8 x i32> [[T4]])
69; CHECK-NEXT:    [[TMP1:%.*]] = trunc <8 x i64> [[X:%.*]] to <8 x i32>
70; CHECK-NEXT:    [[TMP2:%.*]] = shl <8 x i32> [[TMP1]], [[T4]]
71; CHECK-NEXT:    [[T7:%.*]] = and <8 x i32> [[TMP2]], <i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647>
72; CHECK-NEXT:    ret <8 x i32> [[T7]]
73;
74  %t0 = add <8 x i32> %nbits, <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1>
75  %t1 = zext <8 x i32> %t0 to <8 x i64>
76  %t2 = shl <8 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1>, %t1 ; shifting by nbits-1
77  %t3 = add <8 x i64> %t2, <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>
78  %t4 = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32>, %nbits
79
80  call void @use8xi32(<8 x i32> %t0)
81  call void @use8xi64(<8 x i64> %t1)
82  call void @use8xi64(<8 x i64> %t2)
83  call void @use8xi64(<8 x i64> %t3)
84  call void @use8xi32(<8 x i32> %t4)
85
86  %t5 = and <8 x i64> %t3, %x
87  %t6 = trunc <8 x i64> %t5 to <8 x i32>
88  %t7 = shl <8 x i32> %t6, %t4
89  ret <8 x i32> %t7
90}
91
92define <8 x i32> @t2_vec_splat_undef(<8 x i64> %x, <8 x i32> %nbits) {
93; CHECK-LABEL: @t2_vec_splat_undef(
94; CHECK-NEXT:    [[T0:%.*]] = add <8 x i32> [[NBITS:%.*]], <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 undef, i32 -1>
95; CHECK-NEXT:    [[T1:%.*]] = zext <8 x i32> [[T0]] to <8 x i64>
96; CHECK-NEXT:    [[T2:%.*]] = shl <8 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 undef, i64 1>, [[T1]]
97; CHECK-NEXT:    [[T3:%.*]] = add <8 x i64> [[T2]], <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 undef, i64 -1>
98; CHECK-NEXT:    [[T4:%.*]] = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 undef, i32 32>, [[NBITS]]
99; CHECK-NEXT:    call void @use8xi32(<8 x i32> [[T0]])
100; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T1]])
101; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T2]])
102; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T3]])
103; CHECK-NEXT:    call void @use8xi32(<8 x i32> [[T4]])
104; CHECK-NEXT:    [[TMP1:%.*]] = trunc <8 x i64> [[X:%.*]] to <8 x i32>
105; CHECK-NEXT:    [[TMP2:%.*]] = shl <8 x i32> [[TMP1]], [[T4]]
106; CHECK-NEXT:    [[T7:%.*]] = and <8 x i32> [[TMP2]], <i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 poison, i32 2147483647>
107; CHECK-NEXT:    ret <8 x i32> [[T7]]
108;
109  %t0 = add <8 x i32> %nbits, <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 undef, i32 -1>
110  %t1 = zext <8 x i32> %t0 to <8 x i64>
111  %t2 = shl <8 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 undef, i64 1>, %t1 ; shifting by nbits-1
112  %t3 = add <8 x i64> %t2, <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 undef, i64 -1>
113  %t4 = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 undef, i32 32>, %nbits
114
115  call void @use8xi32(<8 x i32> %t0)
116  call void @use8xi64(<8 x i64> %t1)
117  call void @use8xi64(<8 x i64> %t2)
118  call void @use8xi64(<8 x i64> %t3)
119  call void @use8xi32(<8 x i32> %t4)
120
121  %t5 = and <8 x i64> %t3, %x
122  %t6 = trunc <8 x i64> %t5 to <8 x i32>
123  %t7 = shl <8 x i32> %t6, %t4
124  ret <8 x i32> %t7
125}
126
127define <8 x i32> @t3_vec_nonsplat(<8 x i64> %x, <8 x i32> %nbits) {
128; CHECK-LABEL: @t3_vec_nonsplat(
129; CHECK-NEXT:    [[T0:%.*]] = add <8 x i32> [[NBITS:%.*]], <i32 -33, i32 -32, i32 -31, i32 -1, i32 0, i32 1, i32 31, i32 32>
130; CHECK-NEXT:    [[T1:%.*]] = zext <8 x i32> [[T0]] to <8 x i64>
131; CHECK-NEXT:    [[T2:%.*]] = shl <8 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1>, [[T1]]
132; CHECK-NEXT:    [[T3:%.*]] = add <8 x i64> [[T2]], <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>
133; CHECK-NEXT:    [[T4:%.*]] = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32>, [[NBITS]]
134; CHECK-NEXT:    call void @use8xi32(<8 x i32> [[T0]])
135; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T1]])
136; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T2]])
137; CHECK-NEXT:    call void @use8xi64(<8 x i64> [[T3]])
138; CHECK-NEXT:    call void @use8xi32(<8 x i32> [[T4]])
139; CHECK-NEXT:    [[TMP1:%.*]] = trunc <8 x i64> [[X:%.*]] to <8 x i32>
140; CHECK-NEXT:    [[TMP2:%.*]] = shl <8 x i32> [[TMP1]], [[T4]]
141; CHECK-NEXT:    [[T7:%.*]] = and <8 x i32> [[TMP2]], <i32 poison, i32 0, i32 1, i32 2147483647, i32 -1, i32 -1, i32 -1, i32 -1>
142; CHECK-NEXT:    ret <8 x i32> [[T7]]
143;
144  %t0 = add <8 x i32> %nbits, <i32 -33, i32 -32, i32 -31, i32 -1, i32 0, i32 1, i32 31, i32 32>
145  %t1 = zext <8 x i32> %t0 to <8 x i64>
146  %t2 = shl <8 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1, i64 1>, %t1 ; shifting by nbits-1
147  %t3 = add <8 x i64> %t2, <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>
148  %t4 = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32>, %nbits
149
150  call void @use8xi32(<8 x i32> %t0)
151  call void @use8xi64(<8 x i64> %t1)
152  call void @use8xi64(<8 x i64> %t2)
153  call void @use8xi64(<8 x i64> %t3)
154  call void @use8xi32(<8 x i32> %t4)
155
156  %t5 = and <8 x i64> %t3, %x
157  %t6 = trunc <8 x i64> %t5 to <8 x i32>
158  %t7 = shl <8 x i32> %t6, %t4
159  ret <8 x i32> %t7
160}
161
162; Extra uses
163
164define i32 @n4_extrause0(i64 %x, i32 %nbits) {
165; CHECK-LABEL: @n4_extrause0(
166; CHECK-NEXT:    [[T0:%.*]] = add i32 [[NBITS:%.*]], -1
167; CHECK-NEXT:    [[T1:%.*]] = zext i32 [[T0]] to i64
168; CHECK-NEXT:    [[T2:%.*]] = shl i64 1, [[T1]]
169; CHECK-NEXT:    [[T3:%.*]] = add i64 [[T2]], -1
170; CHECK-NEXT:    [[T4:%.*]] = sub i32 32, [[NBITS]]
171; CHECK-NEXT:    call void @use32(i32 [[T0]])
172; CHECK-NEXT:    call void @use64(i64 [[T1]])
173; CHECK-NEXT:    call void @use64(i64 [[T2]])
174; CHECK-NEXT:    call void @use64(i64 [[T3]])
175; CHECK-NEXT:    call void @use32(i32 [[T4]])
176; CHECK-NEXT:    [[T5:%.*]] = and i64 [[T3]], [[X:%.*]]
177; CHECK-NEXT:    call void @use64(i64 [[T5]])
178; CHECK-NEXT:    [[T6:%.*]] = trunc i64 [[T5]] to i32
179; CHECK-NEXT:    [[T7:%.*]] = shl i32 [[T6]], [[T4]]
180; CHECK-NEXT:    ret i32 [[T7]]
181;
182  %t0 = add i32 %nbits, -1
183  %t1 = zext i32 %t0 to i64
184  %t2 = shl i64 1, %t1 ; shifting by nbits-1
185  %t3 = add i64 %t2, -1
186  %t4 = sub i32 32, %nbits
187
188  call void @use32(i32 %t0)
189  call void @use64(i64 %t1)
190  call void @use64(i64 %t2)
191  call void @use64(i64 %t3)
192  call void @use32(i32 %t4)
193
194  %t5 = and i64 %t3, %x
195  call void @use64(i64 %t5)
196  %t6 = trunc i64 %t5 to i32
197  %t7 = shl i32 %t6, %t4
198  ret i32 %t7
199}
200define i32 @n5_extrause1(i64 %x, i32 %nbits) {
201; CHECK-LABEL: @n5_extrause1(
202; CHECK-NEXT:    [[T0:%.*]] = add i32 [[NBITS:%.*]], -1
203; CHECK-NEXT:    [[T1:%.*]] = zext i32 [[T0]] to i64
204; CHECK-NEXT:    [[T2:%.*]] = shl i64 1, [[T1]]
205; CHECK-NEXT:    [[T3:%.*]] = add i64 [[T2]], -1
206; CHECK-NEXT:    [[T4:%.*]] = sub i32 32, [[NBITS]]
207; CHECK-NEXT:    call void @use32(i32 [[T0]])
208; CHECK-NEXT:    call void @use64(i64 [[T1]])
209; CHECK-NEXT:    call void @use64(i64 [[T2]])
210; CHECK-NEXT:    call void @use64(i64 [[T3]])
211; CHECK-NEXT:    call void @use32(i32 [[T4]])
212; CHECK-NEXT:    [[T5:%.*]] = and i64 [[T3]], [[X:%.*]]
213; CHECK-NEXT:    [[T6:%.*]] = trunc i64 [[T5]] to i32
214; CHECK-NEXT:    call void @use32(i32 [[T6]])
215; CHECK-NEXT:    [[T7:%.*]] = shl i32 [[T6]], [[T4]]
216; CHECK-NEXT:    ret i32 [[T7]]
217;
218  %t0 = add i32 %nbits, -1
219  %t1 = zext i32 %t0 to i64
220  %t2 = shl i64 1, %t1 ; shifting by nbits-1
221  %t3 = add i64 %t2, -1
222  %t4 = sub i32 32, %nbits
223
224  call void @use32(i32 %t0)
225  call void @use64(i64 %t1)
226  call void @use64(i64 %t2)
227  call void @use64(i64 %t3)
228  call void @use32(i32 %t4)
229
230  %t5 = and i64 %t3, %x
231  %t6 = trunc i64 %t5 to i32
232  call void @use32(i32 %t6)
233  %t7 = shl i32 %t6, %t4
234  ret i32 %t7
235}
236define i32 @n6_extrause2(i64 %x, i32 %nbits) {
237; CHECK-LABEL: @n6_extrause2(
238; CHECK-NEXT:    [[T0:%.*]] = add i32 [[NBITS:%.*]], -1
239; CHECK-NEXT:    [[T1:%.*]] = zext i32 [[T0]] to i64
240; CHECK-NEXT:    [[T2:%.*]] = shl i64 1, [[T1]]
241; CHECK-NEXT:    [[T3:%.*]] = add i64 [[T2]], -1
242; CHECK-NEXT:    [[T4:%.*]] = sub i32 32, [[NBITS]]
243; CHECK-NEXT:    call void @use32(i32 [[T0]])
244; CHECK-NEXT:    call void @use64(i64 [[T1]])
245; CHECK-NEXT:    call void @use64(i64 [[T2]])
246; CHECK-NEXT:    call void @use64(i64 [[T3]])
247; CHECK-NEXT:    call void @use32(i32 [[T4]])
248; CHECK-NEXT:    [[T5:%.*]] = and i64 [[T3]], [[X:%.*]]
249; CHECK-NEXT:    call void @use64(i64 [[T5]])
250; CHECK-NEXT:    [[T6:%.*]] = trunc i64 [[T5]] to i32
251; CHECK-NEXT:    call void @use32(i32 [[T6]])
252; CHECK-NEXT:    [[T7:%.*]] = shl i32 [[T6]], [[T4]]
253; CHECK-NEXT:    ret i32 [[T7]]
254;
255  %t0 = add i32 %nbits, -1
256  %t1 = zext i32 %t0 to i64
257  %t2 = shl i64 1, %t1 ; shifting by nbits-1
258  %t3 = add i64 %t2, -1
259  %t4 = sub i32 32, %nbits
260
261  call void @use32(i32 %t0)
262  call void @use64(i64 %t1)
263  call void @use64(i64 %t2)
264  call void @use64(i64 %t3)
265  call void @use32(i32 %t4)
266
267  %t5 = and i64 %t3, %x
268  call void @use64(i64 %t5)
269  %t6 = trunc i64 %t5 to i32
270  call void @use32(i32 %t6)
271  %t7 = shl i32 %t6, %t4
272  ret i32 %t7
273}
274