1; Test that the ffs* library call simplifier works correctly.
2;
3; RUN: opt < %s -instcombine -S | FileCheck %s
4; RUN: opt < %s -mtriple i386-pc-linux -instcombine -S | FileCheck %s -check-prefix=CHECK-LINUX
5
6target 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"
7
8declare i32 @ffs(i32)
9declare i32 @ffsl(i32)
10declare i32 @ffsll(i64)
11
12; Check ffs(0) -> 0.
13
14define i32 @test_simplify1() {
15; CHECK-LABEL: @test_simplify1(
16  %ret = call i32 @ffs(i32 0)
17  ret i32 %ret
18; CHECK-NEXT: ret i32 0
19}
20
21define i32 @test_simplify2() {
22; CHECK-LINUX-LABEL: @test_simplify2(
23  %ret = call i32 @ffsl(i32 0)
24  ret i32 %ret
25; CHECK-LINUX-NEXT: ret i32 0
26}
27
28define i32 @test_simplify3() {
29; CHECK-LINUX-LABEL: @test_simplify3(
30  %ret = call i32 @ffsll(i64 0)
31  ret i32 %ret
32; CHECK-LINUX-NEXT: ret i32 0
33}
34
35; Check ffs(c) -> cttz(c) + 1, where 'c' is a constant.
36
37define i32 @test_simplify4() {
38; CHECK-LABEL: @test_simplify4(
39  %ret = call i32 @ffs(i32 1)
40  ret i32 %ret
41; CHECK-NEXT: ret i32 1
42}
43
44define i32 @test_simplify5() {
45; CHECK-LABEL: @test_simplify5(
46  %ret = call i32 @ffs(i32 2048)
47  ret i32 %ret
48; CHECK-NEXT: ret i32 12
49}
50
51define i32 @test_simplify6() {
52; CHECK-LABEL: @test_simplify6(
53  %ret = call i32 @ffs(i32 65536)
54  ret i32 %ret
55; CHECK-NEXT: ret i32 17
56}
57
58define i32 @test_simplify7() {
59; CHECK-LINUX-LABEL: @test_simplify7(
60  %ret = call i32 @ffsl(i32 65536)
61  ret i32 %ret
62; CHECK-LINUX-NEXT: ret i32 17
63}
64
65define i32 @test_simplify8() {
66; CHECK-LINUX-LABEL: @test_simplify8(
67  %ret = call i32 @ffsll(i64 1024)
68  ret i32 %ret
69; CHECK-LINUX-NEXT: ret i32 11
70}
71
72define i32 @test_simplify9() {
73; CHECK-LINUX-LABEL: @test_simplify9(
74  %ret = call i32 @ffsll(i64 65536)
75  ret i32 %ret
76; CHECK-LINUX-NEXT: ret i32 17
77}
78
79define i32 @test_simplify10() {
80; CHECK-LINUX-LABEL: @test_simplify10(
81  %ret = call i32 @ffsll(i64 17179869184)
82  ret i32 %ret
83; CHECK-LINUX-NEXT: ret i32 35
84}
85
86define i32 @test_simplify11() {
87; CHECK-LINUX-LABEL: @test_simplify11(
88  %ret = call i32 @ffsll(i64 281474976710656)
89  ret i32 %ret
90; CHECK-LINUX-NEXT: ret i32 49
91}
92
93define i32 @test_simplify12() {
94; CHECK-LINUX-LABEL: @test_simplify12(
95  %ret = call i32 @ffsll(i64 1152921504606846976)
96  ret i32 %ret
97; CHECK-LINUX-NEXT: ret i32 61
98}
99
100; Check ffs(x) -> x != 0 ? (i32)llvm.cttz(x) + 1 : 0.
101
102define i32 @test_simplify13(i32 %x) {
103; CHECK-LABEL: @test_simplify13(
104  %ret = call i32 @ffs(i32 %x)
105; CHECK-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false)
106; CHECK-NEXT: [[INC:%[a-z0-9]+]] = add nuw nsw i32 [[CTTZ]], 1
107; CHECK-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0
108; CHECK-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0
109  ret i32 %ret
110; CHECK-NEXT: ret i32 [[RET]]
111}
112
113define i32 @test_simplify14(i32 %x) {
114; CHECK-LINUX-LABEL: @test_simplify14(
115  %ret = call i32 @ffsl(i32 %x)
116; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false)
117; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add nuw nsw i32 [[CTTZ]], 1
118; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0
119; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0
120  ret i32 %ret
121; CHECK-LINUX-NEXT: ret i32 [[RET]]
122}
123
124define i32 @test_simplify15(i64 %x) {
125; CHECK-LINUX-LABEL: @test_simplify15(
126  %ret = call i32 @ffsll(i64 %x)
127; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i64 @llvm.cttz.i64(i64 %x, i1 false)
128; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add nuw nsw i64 [[CTTZ]], 1
129; CHECK-LINUX-NEXT: [[TRUNC:%[a-z0-9]+]] = trunc i64 [[INC]] to i32
130; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i64 %x, 0
131; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[TRUNC]], i32 0
132  ret i32 %ret
133; CHECK-LINUX-NEXT: ret i32 [[RET]]
134}
135