1;
2; Here all the branches we unswitch are exiting from the inner loop.
3; That means we should not be getting exponential behavior on inner-loop
4; unswitch. In fact there should be just a single version of inner-loop,
5; with possibly some outer loop copies.
6;
7; There should be just a single copy of each loop when strictest mutiplier
8; candidates formula (unscaled candidates == 0) is enforced:
9
10; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
11; RUN:     -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
12; RUN: -passes='loop(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
13;
14; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
15; RUN:     -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
16; RUN: -passes='loop(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
17;
18; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
19; RUN:     -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
20; RUN: -passes='loop-mssa(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
21;
22; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
23; RUN:     -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
24; RUN: -passes='loop-mssa(simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
25;
26; When we relax the candidates part of a multiplier formula
27; (unscaled candidates == 2) we start getting some unswitches in outer loops,
28; which leads to siblings multiplier kicking in.
29;
30; The tests below also run licm, because it is needed to hoist out
31; loop-invariant freeze instructions, which otherwise may block further
32; unswitching.
33;
34; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
35; RUN:     -unswitch-num-initial-unscaled-candidates=3 -unswitch-siblings-toplevel-div=1 \
36; RUN: -passes='loop-mssa(licm,simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
37; RUN:     sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-UNSCALE3-DIV1
38;
39; NB: sort -b is essential here and below, otherwise blanks might lead to different
40; order depending on locale.
41;
42; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
43; RUN:     -unswitch-num-initial-unscaled-candidates=3 -unswitch-siblings-toplevel-div=2 \
44; RUN: -passes='loop-mssa(licm,simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
45; RUN:     sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-UNSCALE3-DIV2
46;
47; With disabled cost-multiplier we get maximal possible amount of unswitches.
48;
49; RUN: opt < %s -enable-unswitch-cost-multiplier=false \
50; RUN: -passes='loop-mssa(licm,simple-loop-unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
51; RUN:	   sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-MAX
52;
53; Single loop nest, not unswitched
54; LOOP1:     Loop at depth 1 containing:
55; LOOP1-NOT:  Loop at depth 1 containing:
56; LOOP1:     Loop at depth 2 containing:
57; LOOP1-NOT:  Loop at depth 2 containing:
58; LOOP1:     Loop at depth 3 containing:
59; LOOP1-NOT:  Loop at depth 3 containing:
60;
61; Half unswitched loop nests, with unscaled3 and div1 it gets less depth1 loops unswitched
62; since they have more cost.
63; LOOP-UNSCALE3-DIV1-COUNT-4: Loop at depth 1 containing:
64; LOOP-UNSCALE3-DIV1-NOT:      Loop at depth 1 containing:
65; LOOP-UNSCALE3-DIV1-COUNT-1: Loop at depth 2 containing:
66; LOOP-UNSCALE3-DIV1-NOT:      Loop at depth 2 containing:
67; LOOP-UNSCALE3-DIV1-COUNT-1: Loop at depth 3 containing:
68; LOOP-UNSCALE3-DIV1-NOT:      Loop at depth 3 containing:
69;
70; Half unswitched loop nests, with unscaled3 and div2 it gets more depth1 loops unswitched
71; as div2 kicks in.
72; LOOP-UNSCALE3-DIV2-COUNT-6: Loop at depth 1 containing:
73; LOOP-UNSCALE3-DIV2-NOT:      Loop at depth 1 containing:
74; LOOP-UNSCALE3-DIV2-COUNT-1: Loop at depth 2 containing:
75; LOOP-UNSCALE3-DIV2-NOT:      Loop at depth 2 containing:
76; LOOP-UNSCALE3-DIV2-COUNT-1: Loop at depth 3 containing:
77; LOOP-UNSCALE3-DIV2-NOT:      Loop at depth 3 containing:
78;
79; Maximally unswitched (copy of the outer loop per each condition)
80; LOOP-MAX-COUNT-6: Loop at depth 1 containing:
81; LOOP-MAX-NOT:      Loop at depth 1 containing:
82; LOOP-MAX-COUNT-1: Loop at depth 2 containing:
83; LOOP-MAX-NOT:      Loop at depth 2 containing:
84; LOOP-MAX-COUNT-1: Loop at depth 3 containing:
85; LOOP-MAX-NOT:      Loop at depth 3 containing:
86
87declare void @bar()
88
89define void @loop_nested3_conds5(ptr %addr, i1 %c1, i1 %c2, i1 %c3, i1 %c4, i1 %c5) {
90entry:
91  %addr2 = getelementptr i32, ptr %addr, i64 1
92  %addr3 = getelementptr i32, ptr %addr, i64 2
93  br label %outer
94outer:
95  %iv1 = phi i32 [0, %entry], [%iv1.next, %outer_latch]
96  %iv1.next = add i32 %iv1, 1
97  ;; skip nontrivial unswitch
98  call void @bar()
99  br label %middle
100middle:
101  %iv2 = phi i32 [0, %outer], [%iv2.next, %middle_latch]
102  %iv2.next = add i32 %iv2, 1
103  ;; skip nontrivial unswitch
104  call void @bar()
105  br label %loop
106loop:
107  %iv3 = phi i32 [0, %middle], [%iv3.next, %loop_latch]
108  %iv3.next = add i32 %iv3, 1
109  ;; skip nontrivial unswitch
110  call void @bar()
111  br i1 %c1, label %loop_next1_left, label %outer_latch
112loop_next1_left:
113  br label %loop_next1
114loop_next1_right:
115  br label %loop_next1
116
117loop_next1:
118  br i1 %c2, label %loop_next2_left, label %outer_latch
119loop_next2_left:
120  br label %loop_next2
121loop_next2_right:
122  br label %loop_next2
123
124loop_next2:
125  br i1 %c3, label %loop_next3_left, label %outer_latch
126loop_next3_left:
127  br label %loop_next3
128loop_next3_right:
129  br label %loop_next3
130
131loop_next3:
132  br i1 %c4, label %loop_next4_left, label %outer_latch
133loop_next4_left:
134  br label %loop_next4
135loop_next4_right:
136  br label %loop_next4
137
138loop_next4:
139  br i1 %c5, label %loop_latch_left, label %outer_latch
140loop_latch_left:
141  br label %loop_latch
142loop_latch_right:
143  br label %loop_latch
144
145loop_latch:
146  store volatile i32 0, ptr %addr
147  %test_loop = icmp slt i32 %iv3, 50
148  br i1 %test_loop, label %loop, label %middle_latch
149middle_latch:
150  store volatile i32 0, ptr %addr2
151  %test_middle = icmp slt i32 %iv2, 50
152  br i1 %test_middle, label %middle, label %outer_latch
153outer_latch:
154  store volatile i32 0, ptr %addr3
155  %test_outer = icmp slt i32 %iv1, 50
156  br i1 %test_outer, label %outer, label %exit
157exit:
158  ret void
159}
160