2 ; Here we have 5-way unswitchable switch with each successor also having an unswitchable
3 ; exiting branch in it. If we start unswitching those branches we start duplicating the
4 ; whole switch. This can easily lead to exponential behavior w/o proper control.
5 ; On a real-life testcase there was 16-way switch and that took forever to compile w/o
9 ; When we use the stricted multiplier candidates formula (unscaled candidates == 0)
10 ; we should be getting just a single loop.
12 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
13 ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
14 ; RUN: -passes='loop(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
16 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
17 ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
18 ; RUN: -passes='loop(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
20 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
21 ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=1 \
22 ; RUN: -passes='loop-mssa(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
24 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
25 ; RUN: -unswitch-num-initial-unscaled-candidates=0 -unswitch-siblings-toplevel-div=16 \
26 ; RUN: -passes='loop-mssa(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | FileCheck %s --check-prefixes=LOOP1
28 ; With relaxed candidates multiplier (unscaled candidates == 8) we should allow
29 ; some unswitches to happen until siblings multiplier starts kicking in:
31 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
32 ; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=1 \
33 ; RUN: -passes='loop(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
34 ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-RELAX
36 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
37 ; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=1 \
38 ; RUN: -passes='loop-mssa(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
39 ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-RELAX
41 ; With relaxed candidates multiplier (unscaled candidates == 8) and with relaxed
42 ; siblings multiplier for top-level loops (toplevel-div == 8) we should get
43 ; considerably more copies of the loop (especially top-level ones).
45 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
46 ; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=8 \
47 ; RUN: -passes='loop(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
48 ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-RELAX2
50 ; RUN: opt < %s -enable-unswitch-cost-multiplier=true \
51 ; RUN: -unswitch-num-initial-unscaled-candidates=8 -unswitch-siblings-toplevel-div=8 \
52 ; RUN: -passes='loop-mssa(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
53 ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-RELAX2
55 ; We get hundreds of copies of the loop when cost multiplier is disabled:
57 ; RUN: opt < %s -enable-unswitch-cost-multiplier=false \
58 ; RUN: -passes='loop(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
59 ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-MAX
61 ; RUN: opt < %s -enable-unswitch-cost-multiplier=false \
62 ; RUN: -passes='loop-mssa(unswitch<nontrivial>),print<loops>' -disable-output 2>&1 | \
63 ; RUN: sort -b -k 1 | FileCheck %s --check-prefixes=LOOP-MAX
65 ; Single loop nest, not unswitched
66 ; LOOP1: Loop at depth 1 containing:
67 ; LOOP1-NOT: Loop at depth 1 containing:
68 ; LOOP1: Loop at depth 2 containing:
69 ; LOOP1-NOT: Loop at depth 2 containing:
71 ; Somewhat relaxed restrictions on candidates:
72 ; LOOP-RELAX-COUNT-5: Loop at depth 1 containing:
73 ; LOOP-RELAX-NOT: Loop at depth 1 containing:
74 ; LOOP-RELAX-COUNT-32: Loop at depth 2 containing:
75 ; LOOP-RELAX-NOT: Loop at depth 2 containing:
77 ; Even more relaxed restrictions on candidates and siblings.
78 ; LOOP-RELAX2-COUNT-11: Loop at depth 1 containing:
79 ; LOOP-RELAX2-NOT: Loop at depth 1 containing:
80 ; LOOP-RELAX2-COUNT-40: Loop at depth 2 containing:
81 ; LOOP-RELAX-NOT: Loop at depth 2 containing:
83 ; Unswitched as much as it could (with multiplier disabled).
84 ; LOOP-MAX-COUNT-56: Loop at depth 1 containing:
85 ; LOOP-MAX-NOT: Loop at depth 1 containing:
86 ; LOOP-MAX-COUNT-111: Loop at depth 2 containing:
87 ; LOOP-MAX-NOT: Loop at depth 2 containing:
89 define i32 @loop_switch(i32* %addr, i32 %c1, i32 %c2) {
91 %addr1 = getelementptr i32, i32* %addr, i64 0
92 %addr2 = getelementptr i32, i32* %addr, i64 1
93 %check0 = icmp eq i32 %c2, 0
94 %check1 = icmp eq i32 %c2, 31
95 %check2 = icmp eq i32 %c2, 32
96 %check3 = icmp eq i32 %c2, 33
97 %check4 = icmp eq i32 %c2, 34
101 %iv1 = phi i32 [0, %entry], [%iv1.next, %outer_latch]
102 %iv1.next = add i32 %iv1, 1
105 %iv2 = phi i32 [0, %outer_loop], [%iv2.next, %inner_latch]
106 %iv2.next = add i32 %iv2, 1
107 switch i32 %c1, label %inner_latch [
116 br i1 %check4, label %exit, label %inner_latch
118 br i1 %check3, label %exit, label %inner_latch
120 br i1 %check2, label %exit, label %inner_latch
122 br i1 %check1, label %exit, label %inner_latch
124 br i1 %check0, label %exit, label %inner_latch
127 store volatile i32 0, i32* %addr1
128 %test_inner = icmp slt i32 %iv2, 50
129 br i1 %test_inner, label %inner_loop, label %outer_latch
132 store volatile i32 0, i32* %addr2
133 %test_outer = icmp slt i32 %iv1, 50
134 br i1 %test_outer, label %outer_loop, label %exit
136 exit: ; preds = %bci_0