xref: /llvm-project/llvm/test/Transforms/InstCombine/compare-signs.ll (revision 4e066b6be42f731eda3ee221d12d9c3d5d21177e)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -passes=instcombine -S < %s | FileCheck %s
3
4; PR5438
5
6define i32 @test1(i32 %a, i32 %b) nounwind readnone {
7; CHECK-LABEL: @test1(
8; CHECK-NEXT:    [[TMP1:%.*]] = xor i32 [[B:%.*]], [[A:%.*]]
9; CHECK-NEXT:    [[T2:%.*]] = icmp sgt i32 [[TMP1]], -1
10; CHECK-NEXT:    [[T3:%.*]] = zext i1 [[T2]] to i32
11; CHECK-NEXT:    ret i32 [[T3]]
12;
13  %t0 = icmp sgt i32 %a, -1
14  %t1 = icmp slt i32 %b, 0
15  %t2 = xor i1 %t1, %t0
16  %t3 = zext i1 %t2 to i32
17  ret i32 %t3
18}
19
20; TODO: This optimizes partially but not all the way.
21define i32 @test2(i32 %a, i32 %b) nounwind readnone {
22; CHECK-LABEL: @test2(
23; CHECK-NEXT:    [[TMP1:%.*]] = xor i32 [[A:%.*]], [[B:%.*]]
24; CHECK-NEXT:    [[TMP2:%.*]] = lshr i32 [[TMP1]], 3
25; CHECK-NEXT:    [[DOTLOBIT:%.*]] = and i32 [[TMP2]], 1
26; CHECK-NEXT:    [[T3:%.*]] = xor i32 [[DOTLOBIT]], 1
27; CHECK-NEXT:    ret i32 [[T3]]
28;
29  %t0 = and i32 %a, 8
30  %t1 = and i32 %b, 8
31  %t2 = icmp eq i32 %t0, %t1
32  %t3 = zext i1 %t2 to i32
33  ret i32 %t3
34}
35
36define i32 @test3(i32 %a, i32 %b) nounwind readnone {
37; CHECK-LABEL: @test3(
38; CHECK-NEXT:    [[T2_UNSHIFTED:%.*]] = xor i32 [[A:%.*]], [[B:%.*]]
39; CHECK-NEXT:    [[T2:%.*]] = icmp sgt i32 [[T2_UNSHIFTED]], -1
40; CHECK-NEXT:    [[T3:%.*]] = zext i1 [[T2]] to i32
41; CHECK-NEXT:    ret i32 [[T3]]
42;
43  %t0 = lshr i32 %a, 31
44  %t1 = lshr i32 %b, 31
45  %t2 = icmp eq i32 %t0, %t1
46  %t3 = zext i1 %t2 to i32
47  ret i32 %t3
48}
49
50define <2 x i32> @test3vec(<2 x i32> %a, <2 x i32> %b) nounwind readnone {
51; CHECK-LABEL: @test3vec(
52; CHECK-NEXT:    [[T2_UNSHIFTED:%.*]] = xor <2 x i32> [[A:%.*]], [[B:%.*]]
53; CHECK-NEXT:    [[T2:%.*]] = icmp sgt <2 x i32> [[T2_UNSHIFTED]], splat (i32 -1)
54; CHECK-NEXT:    [[T3:%.*]] = zext <2 x i1> [[T2]] to <2 x i32>
55; CHECK-NEXT:    ret <2 x i32> [[T3]]
56;
57  %t0 = lshr <2 x i32> %a, <i32 31, i32 31>
58  %t1 = lshr <2 x i32> %b, <i32 31, i32 31>
59  %t2 = icmp eq <2 x i32> %t0, %t1
60  %t3 = zext <2 x i1> %t2 to <2 x i32>
61  ret <2 x i32> %t3
62}
63
64define <2 x i32> @test3vec_poison1(<2 x i32> %a, <2 x i32> %b) nounwind readnone {
65; CHECK-LABEL: @test3vec_poison1(
66; CHECK-NEXT:    [[T2_UNSHIFTED:%.*]] = xor <2 x i32> [[A:%.*]], [[B:%.*]]
67; CHECK-NEXT:    [[T2:%.*]] = icmp ult <2 x i32> [[T2_UNSHIFTED]], splat (i32 16777216)
68; CHECK-NEXT:    [[T3:%.*]] = zext <2 x i1> [[T2]] to <2 x i32>
69; CHECK-NEXT:    ret <2 x i32> [[T3]]
70;
71  %t0 = lshr <2 x i32> %a, <i32 24, i32 poison>
72  %t1 = lshr <2 x i32> %b, <i32 24, i32 24>
73  %t2 = icmp eq <2 x i32> %t0, %t1
74  %t3 = zext <2 x i1> %t2 to <2 x i32>
75  ret <2 x i32> %t3
76}
77
78define <2 x i32> @test3vec_poison2(<2 x i32> %a, <2 x i32> %b) nounwind readnone {
79; CHECK-LABEL: @test3vec_poison2(
80; CHECK-NEXT:    [[T2_UNSHIFTED:%.*]] = xor <2 x i32> [[A:%.*]], [[B:%.*]]
81; CHECK-NEXT:    [[T2:%.*]] = icmp ult <2 x i32> [[T2_UNSHIFTED]], splat (i32 131072)
82; CHECK-NEXT:    [[T3:%.*]] = zext <2 x i1> [[T2]] to <2 x i32>
83; CHECK-NEXT:    ret <2 x i32> [[T3]]
84;
85  %t0 = lshr <2 x i32> %a, <i32 poison, i32 17>
86  %t1 = lshr <2 x i32> %b, <i32 poison, i32 17>
87  %t2 = icmp eq <2 x i32> %t0, %t1
88  %t3 = zext <2 x i1> %t2 to <2 x i32>
89  ret <2 x i32> %t3
90}
91
92; negative test
93
94define <2 x i32> @test3vec_diff(<2 x i32> %a, <2 x i32> %b) nounwind readnone {
95; CHECK-LABEL: @test3vec_diff(
96; CHECK-NEXT:    [[T0:%.*]] = lshr <2 x i32> [[A:%.*]], splat (i32 31)
97; CHECK-NEXT:    [[T1:%.*]] = lshr <2 x i32> [[B:%.*]], splat (i32 30)
98; CHECK-NEXT:    [[T2:%.*]] = icmp eq <2 x i32> [[T0]], [[T1]]
99; CHECK-NEXT:    [[T3:%.*]] = zext <2 x i1> [[T2]] to <2 x i32>
100; CHECK-NEXT:    ret <2 x i32> [[T3]]
101;
102  %t0 = lshr <2 x i32> %a, <i32 31, i32 31>
103  %t1 = lshr <2 x i32> %b, <i32 30, i32 30>
104  %t2 = icmp eq <2 x i32> %t0, %t1
105  %t3 = zext <2 x i1> %t2 to <2 x i32>
106  ret <2 x i32> %t3
107}
108
109define <2 x i32> @test3vec_non-uniform(<2 x i32> %a, <2 x i32> %b) nounwind readnone {
110; CHECK-LABEL: @test3vec_non-uniform(
111; CHECK-NEXT:    [[T0:%.*]] = lshr <2 x i32> [[A:%.*]], <i32 30, i32 31>
112; CHECK-NEXT:    [[T1:%.*]] = lshr <2 x i32> [[B:%.*]], <i32 30, i32 31>
113; CHECK-NEXT:    [[T2:%.*]] = icmp eq <2 x i32> [[T0]], [[T1]]
114; CHECK-NEXT:    [[T3:%.*]] = zext <2 x i1> [[T2]] to <2 x i32>
115; CHECK-NEXT:    ret <2 x i32> [[T3]]
116;
117  %t0 = lshr <2 x i32> %a, <i32 30, i32 31>
118  %t1 = lshr <2 x i32> %b, <i32 30, i32 31>
119  %t2 = icmp eq <2 x i32> %t0, %t1
120  %t3 = zext <2 x i1> %t2 to <2 x i32>
121  ret <2 x i32> %t3
122}
123
124; Variation on @test3: checking the 2nd bit in a situation where the 5th bit
125; is one, not zero.
126define i32 @test3i(i32 %a, i32 %b) nounwind readnone {
127; CHECK-LABEL: @test3i(
128; CHECK-NEXT:    [[T01:%.*]] = xor i32 [[A:%.*]], [[B:%.*]]
129; CHECK-NEXT:    [[T4:%.*]] = icmp sgt i32 [[T01]], -1
130; CHECK-NEXT:    [[T5:%.*]] = zext i1 [[T4]] to i32
131; CHECK-NEXT:    ret i32 [[T5]]
132;
133  %t0 = lshr i32 %a, 29
134  %t1 = lshr i32 %b, 29
135  %t2 = or i32 %t0, 35
136  %t3 = or i32 %t1, 35
137  %t4 = icmp eq i32 %t2, %t3
138  %t5 = zext i1 %t4 to i32
139  ret i32 %t5
140}
141
142define i1 @test4a(i32 %a) {
143; CHECK-LABEL: @test4a(
144; CHECK-NEXT:    [[C:%.*]] = icmp slt i32 [[A:%.*]], 1
145; CHECK-NEXT:    ret i1 [[C]]
146;
147  %l = ashr i32 %a, 31
148  %na = sub i32 0, %a
149  %r = lshr i32 %na, 31
150  %signum = or i32 %l, %r
151  %c = icmp slt i32 %signum, 1
152  ret i1 %c
153}
154
155define i1 @test4a_commuted(i32 %a) {
156; CHECK-LABEL: @test4a_commuted(
157; CHECK-NEXT:    [[C:%.*]] = icmp slt i32 [[SIGNUM:%.*]], 1
158; CHECK-NEXT:    ret i1 [[C]]
159;
160  %l = ashr i32 %a, 31
161  %na = sub i32 0, %a
162  %r = lshr i32 %na, 31
163  %signum = or i32 %r, %l
164  %c = icmp slt i32 %signum, 1
165  ret i1 %c
166}
167
168define <2 x i1> @test4a_vec(<2 x i32> %a) {
169; CHECK-LABEL: @test4a_vec(
170; CHECK-NEXT:    [[C:%.*]] = icmp slt <2 x i32> [[A:%.*]], splat (i32 1)
171; CHECK-NEXT:    ret <2 x i1> [[C]]
172;
173  %l = ashr <2 x i32> %a, <i32 31, i32 31>
174  %na = sub <2 x i32> zeroinitializer, %a
175  %r = lshr <2 x i32> %na, <i32 31, i32 31>
176  %signum = or <2 x i32> %l, %r
177  %c = icmp slt <2 x i32> %signum, <i32 1, i32 1>
178  ret <2 x i1> %c
179}
180
181define i1 @test4b(i64 %a) {
182; CHECK-LABEL: @test4b(
183; CHECK-NEXT:    [[C:%.*]] = icmp slt i64 [[A:%.*]], 1
184; CHECK-NEXT:    ret i1 [[C]]
185;
186  %l = ashr i64 %a, 63
187  %na = sub i64 0, %a
188  %r = lshr i64 %na, 63
189  %signum = or i64 %l, %r
190  %c = icmp slt i64 %signum, 1
191  ret i1 %c
192}
193
194define i1 @test4c(i64 %a) {
195; CHECK-LABEL: @test4c(
196; CHECK-NEXT:    [[C:%.*]] = icmp slt i64 [[A:%.*]], 1
197; CHECK-NEXT:    ret i1 [[C]]
198;
199  %l = ashr i64 %a, 63
200  %na = sub i64 0, %a
201  %r = lshr i64 %na, 63
202  %signum = or i64 %l, %r
203  %signum.trunc = trunc i64 %signum to i32
204  %c = icmp slt i32 %signum.trunc, 1
205  ret i1 %c
206}
207
208define <2 x i1> @test4c_vec(<2 x i64> %a) {
209; CHECK-LABEL: @test4c_vec(
210; CHECK-NEXT:    [[C:%.*]] = icmp slt <2 x i64> [[A:%.*]], splat (i64 1)
211; CHECK-NEXT:    ret <2 x i1> [[C]]
212;
213  %l = ashr <2 x i64> %a, <i64 63, i64 63>
214  %na = sub <2 x i64> zeroinitializer, %a
215  %r = lshr <2 x i64> %na, <i64 63, i64 63>
216  %signum = or <2 x i64> %l, %r
217  %signum.trunc = trunc <2 x i64> %signum to <2 x i32>
218  %c = icmp slt <2 x i32> %signum.trunc, <i32 1, i32 1>
219  ret <2 x i1> %c
220}
221
222; PR49866
223
224define i1 @shift_trunc_signbit_test(i32 %x) {
225; CHECK-LABEL: @shift_trunc_signbit_test(
226; CHECK-NEXT:    [[R:%.*]] = icmp slt i32 [[X:%.*]], 0
227; CHECK-NEXT:    ret i1 [[R]]
228;
229  %sh = lshr i32 %x, 24
230  %tr = trunc i32 %sh to i8
231  %r = icmp slt i8 %tr, 0
232  ret i1 %r
233}
234
235define <2 x i1> @shift_trunc_signbit_test_vec_uses(<2 x i17> %x, ptr %p1, ptr %p2) {
236; CHECK-LABEL: @shift_trunc_signbit_test_vec_uses(
237; CHECK-NEXT:    [[SH:%.*]] = lshr <2 x i17> [[X:%.*]], splat (i17 4)
238; CHECK-NEXT:    store <2 x i17> [[SH]], ptr [[P1:%.*]], align 8
239; CHECK-NEXT:    [[TR:%.*]] = trunc nuw <2 x i17> [[SH]] to <2 x i13>
240; CHECK-NEXT:    store <2 x i13> [[TR]], ptr [[P2:%.*]], align 4
241; CHECK-NEXT:    [[R:%.*]] = icmp sgt <2 x i17> [[X]], splat (i17 -1)
242; CHECK-NEXT:    ret <2 x i1> [[R]]
243;
244  %sh = lshr <2 x i17> %x, <i17 4, i17 4>
245  store <2 x i17> %sh, ptr %p1
246  %tr = trunc <2 x i17> %sh to <2 x i13>
247  store <2 x i13> %tr, ptr %p2
248  %r = icmp sgt <2 x i13> %tr, <i13 -1, i13 -1>
249  ret <2 x i1> %r
250}
251
252; negative test - but this reduces with a mask op
253
254define i1 @shift_trunc_wrong_shift(i32 %x) {
255; CHECK-LABEL: @shift_trunc_wrong_shift(
256; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[X:%.*]], 1073741824
257; CHECK-NEXT:    [[R:%.*]] = icmp ne i32 [[TMP1]], 0
258; CHECK-NEXT:    ret i1 [[R]]
259;
260  %sh = lshr i32 %x, 23
261  %tr = trunc i32 %sh to i8
262  %r = icmp slt i8 %tr, 0
263  ret i1 %r
264}
265
266; negative test
267
268define i1 @shift_trunc_wrong_cmp(i32 %x) {
269; CHECK-LABEL: @shift_trunc_wrong_cmp(
270; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 24
271; CHECK-NEXT:    [[TR:%.*]] = trunc nuw i32 [[SH]] to i8
272; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[TR]], 1
273; CHECK-NEXT:    ret i1 [[R]]
274;
275  %sh = lshr i32 %x, 24
276  %tr = trunc i32 %sh to i8
277  %r = icmp slt i8 %tr, 1
278  ret i1 %r
279}
280