Skip to content

Commit 56e09c6

Browse files
rotaterightrotateright
committed
[InstCombine] add tests for lack of abs/nabs canonicalization; NFC
llvm-svn: 332726
1 parent fa3e460 commit 56e09c6

File tree

1 file changed

+141
-24
lines changed
  • llvm/test/Transforms/InstCombine

1 file changed

+141
-24
lines changed

‎llvm/test/Transforms/InstCombine/abs-1.ll

Lines changed: 141 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -1,3 +1,4 @@
1+
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
12
; RUN: opt < %s -instcombine -S | FileCheck %s
23

34
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
@@ -11,9 +12,9 @@ declare i64 @llabs(i64)
1112

1213
define i32 @test_abs(i32 %x) {
1314
; CHECK-LABEL: @test_abs(
14-
; CHECK-NEXT: [[ISPOS:%.*]] = icmp sgt i32 %x, -1
15-
; CHECK-NEXT: [[NEG:%.*]] = sub i32 0, %x
16-
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[ISPOS]], i32 %x, i32 [[NEG]]
15+
; CHECK-NEXT: [[ISPOS:%.*]] = icmp sgt i32 [[X:%.*]], -1
16+
; CHECK-NEXT: [[NEG:%.*]] = sub i32 0, [[X]]
17+
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[ISPOS]], i32 [[X]], i32 [[NEG]]
1718
; CHECK-NEXT: ret i32 [[TMP1]]
1819
;
1920
%ret = call i32 @abs(i32 %x)
@@ -22,9 +23,9 @@ define i32 @test_abs(i32 %x) {
2223

2324
define i64 @test_labs(i64 %x) {
2425
; CHECK-LABEL: @test_labs(
25-
; CHECK-NEXT: [[ISPOS:%.*]] = icmp sgt i64 %x, -1
26-
; CHECK-NEXT: [[NEG:%.*]] = sub i64 0, %x
27-
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[ISPOS]], i64 %x, i64 [[NEG]]
26+
; CHECK-NEXT: [[ISPOS:%.*]] = icmp sgt i64 [[X:%.*]], -1
27+
; CHECK-NEXT: [[NEG:%.*]] = sub i64 0, [[X]]
28+
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[ISPOS]], i64 [[X]], i64 [[NEG]]
2829
; CHECK-NEXT: ret i64 [[TMP1]]
2930
;
3031
%ret = call i64 @labs(i64 %x)
@@ -33,24 +34,140 @@ define i64 @test_labs(i64 %x) {
3334

3435
define i64 @test_llabs(i64 %x) {
3536
; CHECK-LABEL: @test_llabs(
36-
; CHECK-NEXT: [[ISPOS:%.*]] = icmp sgt i64 %x, -1
37-
; CHECK-NEXT: [[NEG:%.*]] = sub i64 0, %x
38-
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[ISPOS]], i64 %x, i64 [[NEG]]
37+
; CHECK-NEXT: [[ISPOS:%.*]] = icmp sgt i64 [[X:%.*]], -1
38+
; CHECK-NEXT: [[NEG:%.*]] = sub i64 0, [[X]]
39+
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[ISPOS]], i64 [[X]], i64 [[NEG]]
3940
; CHECK-NEXT: ret i64 [[TMP1]]
4041
;
4142
%ret = call i64 @llabs(i64 %x)
4243
ret i64 %ret
4344
}
4445

46+
; FIXME: We should have a canonical form of abs to make CSE easier.
47+
48+
define i8 @abs_canonical_1(i8 %x) {
49+
; CHECK-LABEL: @abs_canonical_1(
50+
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 0
51+
; CHECK-NEXT: [[NEG:%.*]] = sub i8 0, [[X]]
52+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[CMP]], i8 [[X]], i8 [[NEG]]
53+
; CHECK-NEXT: ret i8 [[ABS]]
54+
;
55+
%cmp = icmp sgt i8 %x, 0
56+
%neg = sub i8 0, %x
57+
%abs = select i1 %cmp, i8 %x, i8 %neg
58+
ret i8 %abs
59+
}
60+
61+
; FIXME: Vectors should work too.
62+
63+
define <2 x i8> @abs_canonical_2(<2 x i8> %x) {
64+
; CHECK-LABEL: @abs_canonical_2(
65+
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <2 x i8> [[X:%.*]], <i8 -1, i8 -1>
66+
; CHECK-NEXT: [[NEG:%.*]] = sub <2 x i8> zeroinitializer, [[X]]
67+
; CHECK-NEXT: [[ABS:%.*]] = select <2 x i1> [[CMP]], <2 x i8> [[X]], <2 x i8> [[NEG]]
68+
; CHECK-NEXT: ret <2 x i8> [[ABS]]
69+
;
70+
%cmp = icmp sgt <2 x i8> %x, <i8 -1, i8 -1>
71+
%neg = sub <2 x i8> zeroinitializer, %x
72+
%abs = select <2 x i1> %cmp, <2 x i8> %x, <2 x i8> %neg
73+
ret <2 x i8> %abs
74+
}
75+
76+
; NSW should not change.
77+
78+
define i8 @abs_canonical_3(i8 %x) {
79+
; CHECK-LABEL: @abs_canonical_3(
80+
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[X:%.*]], 0
81+
; CHECK-NEXT: [[NEG:%.*]] = sub nsw i8 0, [[X]]
82+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[CMP]], i8 [[NEG]], i8 [[X]]
83+
; CHECK-NEXT: ret i8 [[ABS]]
84+
;
85+
%cmp = icmp slt i8 %x, 0
86+
%neg = sub nsw i8 0, %x
87+
%abs = select i1 %cmp, i8 %neg, i8 %x
88+
ret i8 %abs
89+
}
90+
91+
define i8 @abs_canonical_4(i8 %x) {
92+
; CHECK-LABEL: @abs_canonical_4(
93+
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[X:%.*]], 1
94+
; CHECK-NEXT: [[NEG:%.*]] = sub i8 0, [[X]]
95+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[CMP]], i8 [[NEG]], i8 [[X]]
96+
; CHECK-NEXT: ret i8 [[ABS]]
97+
;
98+
%cmp = icmp slt i8 %x, 1
99+
%neg = sub i8 0, %x
100+
%abs = select i1 %cmp, i8 %neg, i8 %x
101+
ret i8 %abs
102+
}
103+
104+
; FIXME: We should have a canonical form of nabs to make CSE easier.
105+
106+
define i8 @nabs_canonical_1(i8 %x) {
107+
; CHECK-LABEL: @nabs_canonical_1(
108+
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 0
109+
; CHECK-NEXT: [[NEG:%.*]] = sub i8 0, [[X]]
110+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[CMP]], i8 [[NEG]], i8 [[X]]
111+
; CHECK-NEXT: ret i8 [[ABS]]
112+
;
113+
%cmp = icmp sgt i8 %x, 0
114+
%neg = sub i8 0, %x
115+
%abs = select i1 %cmp, i8 %neg, i8 %x
116+
ret i8 %abs
117+
}
118+
119+
; FIXME: Vectors should work too.
120+
121+
define <2 x i8> @nabs_canonical_2(<2 x i8> %x) {
122+
; CHECK-LABEL: @nabs_canonical_2(
123+
; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <2 x i8> [[X:%.*]], <i8 -1, i8 -1>
124+
; CHECK-NEXT: [[NEG:%.*]] = sub <2 x i8> zeroinitializer, [[X]]
125+
; CHECK-NEXT: [[ABS:%.*]] = select <2 x i1> [[CMP]], <2 x i8> [[NEG]], <2 x i8> [[X]]
126+
; CHECK-NEXT: ret <2 x i8> [[ABS]]
127+
;
128+
%cmp = icmp sgt <2 x i8> %x, <i8 -1, i8 -1>
129+
%neg = sub <2 x i8> zeroinitializer, %x
130+
%abs = select <2 x i1> %cmp, <2 x i8> %neg, <2 x i8> %x
131+
ret <2 x i8> %abs
132+
}
133+
134+
; NSW should not change.
135+
136+
define i8 @nabs_canonical_3(i8 %x) {
137+
; CHECK-LABEL: @nabs_canonical_3(
138+
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[X:%.*]], 0
139+
; CHECK-NEXT: [[NEG:%.*]] = sub nsw i8 0, [[X]]
140+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[CMP]], i8 [[X]], i8 [[NEG]]
141+
; CHECK-NEXT: ret i8 [[ABS]]
142+
;
143+
%cmp = icmp slt i8 %x, 0
144+
%neg = sub nsw i8 0, %x
145+
%abs = select i1 %cmp, i8 %x, i8 %neg
146+
ret i8 %abs
147+
}
148+
149+
define i8 @nabs_canonical_4(i8 %x) {
150+
; CHECK-LABEL: @nabs_canonical_4(
151+
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[X:%.*]], 1
152+
; CHECK-NEXT: [[NEG:%.*]] = sub i8 0, [[X]]
153+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[CMP]], i8 [[X]], i8 [[NEG]]
154+
; CHECK-NEXT: ret i8 [[ABS]]
155+
;
156+
%cmp = icmp slt i8 %x, 1
157+
%neg = sub i8 0, %x
158+
%abs = select i1 %cmp, i8 %x, i8 %neg
159+
ret i8 %abs
160+
}
161+
45162
; The following 5 tests use a shift+add+xor to implement abs():
46163
; B = ashr i8 A, 7 -- smear the sign bit.
47164
; xor (add A, B), B -- add -1 and flip bits if negative
48165

49166
define i8 @shifty_abs_commute0(i8 %x) {
50167
; CHECK-LABEL: @shifty_abs_commute0(
51-
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i8 %x, 0
52-
; CHECK-NEXT: [[TMP2:%.*]] = sub i8 0, %x
53-
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 [[TMP2]], i8 %x
168+
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i8 [[X:%.*]], 0
169+
; CHECK-NEXT: [[TMP2:%.*]] = sub i8 0, [[X]]
170+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 [[TMP2]], i8 [[X]]
54171
; CHECK-NEXT: ret i8 [[ABS]]
55172
;
56173
%signbit = ashr i8 %x, 7
@@ -61,9 +178,9 @@ define i8 @shifty_abs_commute0(i8 %x) {
61178

62179
define i8 @shifty_abs_commute0_nsw(i8 %x) {
63180
; CHECK-LABEL: @shifty_abs_commute0_nsw(
64-
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i8 %x, 0
65-
; CHECK-NEXT: [[TMP2:%.*]] = sub nsw i8 0, %x
66-
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 [[TMP2]], i8 %x
181+
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i8 [[X:%.*]], 0
182+
; CHECK-NEXT: [[TMP2:%.*]] = sub nsw i8 0, [[X]]
183+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 [[TMP2]], i8 [[X]]
67184
; CHECK-NEXT: ret i8 [[ABS]]
68185
;
69186
%signbit = ashr i8 %x, 7
@@ -77,8 +194,8 @@ define i8 @shifty_abs_commute0_nsw(i8 %x) {
77194
; have produced all 1s. We partially optimize this.
78195
define i8 @shifty_abs_commute0_nuw(i8 %x) {
79196
; CHECK-LABEL: @shifty_abs_commute0_nuw(
80-
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i8 %x, 0
81-
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 %x, i8 0
197+
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt i8 [[X:%.*]], 0
198+
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 [[X]], i8 0
82199
; CHECK-NEXT: ret i8 [[ABS]]
83200
;
84201
%signbit = ashr i8 %x, 7
@@ -89,9 +206,9 @@ define i8 @shifty_abs_commute0_nuw(i8 %x) {
89206

90207
define <2 x i8> @shifty_abs_commute1(<2 x i8> %x) {
91208
; CHECK-LABEL: @shifty_abs_commute1(
92-
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <2 x i8> %x, zeroinitializer
93-
; CHECK-NEXT: [[TMP2:%.*]] = sub <2 x i8> zeroinitializer, %x
94-
; CHECK-NEXT: [[ABS:%.*]] = select <2 x i1> [[TMP1]], <2 x i8> [[TMP2]], <2 x i8> %x
209+
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <2 x i8> [[X:%.*]], zeroinitializer
210+
; CHECK-NEXT: [[TMP2:%.*]] = sub <2 x i8> zeroinitializer, [[X]]
211+
; CHECK-NEXT: [[ABS:%.*]] = select <2 x i1> [[TMP1]], <2 x i8> [[TMP2]], <2 x i8> [[X]]
95212
; CHECK-NEXT: ret <2 x i8> [[ABS]]
96213
;
97214
%signbit = ashr <2 x i8> %x, <i8 7, i8 7>
@@ -102,7 +219,7 @@ define <2 x i8> @shifty_abs_commute1(<2 x i8> %x) {
102219

103220
define <2 x i8> @shifty_abs_commute2(<2 x i8> %x) {
104221
; CHECK-LABEL: @shifty_abs_commute2(
105-
; CHECK-NEXT: [[Y:%.*]] = mul <2 x i8> %x, <i8 3, i8 3>
222+
; CHECK-NEXT: [[Y:%.*]] = mul <2 x i8> [[X:%.*]], <i8 3, i8 3>
106223
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <2 x i8> [[Y]], zeroinitializer
107224
; CHECK-NEXT: [[TMP2:%.*]] = sub <2 x i8> zeroinitializer, [[Y]]
108225
; CHECK-NEXT: [[ABS:%.*]] = select <2 x i1> [[TMP1]], <2 x i8> [[TMP2]], <2 x i8> [[Y]]
@@ -117,7 +234,7 @@ define <2 x i8> @shifty_abs_commute2(<2 x i8> %x) {
117234

118235
define i8 @shifty_abs_commute3(i8 %x) {
119236
; CHECK-LABEL: @shifty_abs_commute3(
120-
; CHECK-NEXT: [[Y:%.*]] = mul i8 %x, 3
237+
; CHECK-NEXT: [[Y:%.*]] = mul i8 [[X:%.*]], 3
121238
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i8 [[Y]], 0
122239
; CHECK-NEXT: [[TMP2:%.*]] = sub i8 0, [[Y]]
123240
; CHECK-NEXT: [[ABS:%.*]] = select i1 [[TMP1]], i8 [[TMP2]], i8 [[Y]]
@@ -136,8 +253,8 @@ declare void @extra_use(i8)
136253

137254
define i8 @shifty_abs_too_many_uses(i8 %x) {
138255
; CHECK-LABEL: @shifty_abs_too_many_uses(
139-
; CHECK-NEXT: [[SIGNBIT:%.*]] = ashr i8 %x, 7
140-
; CHECK-NEXT: [[ADD:%.*]] = add i8 [[SIGNBIT]], %x
256+
; CHECK-NEXT: [[SIGNBIT:%.*]] = ashr i8 [[X:%.*]], 7
257+
; CHECK-NEXT: [[ADD:%.*]] = add i8 [[SIGNBIT]], [[X]]
141258
; CHECK-NEXT: [[ABS:%.*]] = xor i8 [[ADD]], [[SIGNBIT]]
142259
; CHECK-NEXT: call void @extra_use(i8 [[SIGNBIT]])
143260
; CHECK-NEXT: ret i8 [[ABS]]

0 commit comments

Comments
 (0)