1 ; In this test we check how heuristics for complete unrolling work. We have
4 ; 3) -unroll-percent-dynamic-cost-saved-threshold and
5 ; 2) -unroll-dynamic-cost-savings-discount
7 ; They control loop-unrolling according to the following rules:
8 ; * If size of unrolled loop exceeds the absoulte threshold, we don't unroll
9 ; this loop under any circumstances.
10 ; * If size of unrolled loop is below the '-unroll-threshold', then we'll
11 ; consider this loop as a very small one, and completely unroll it.
12 ; * If a loop size is between these two tresholds, we only do complete unroll
13 ; it if estimated number of potentially optimized instructions is high (we
14 ; specify the minimal percent of such instructions).
16 ; In this particular test-case, complete unrolling will allow later
17 ; optimizations to remove ~55% of the instructions, the loop body size is 9,
18 ; and unrolled size is 65.
20 ; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=10 -unroll-max-percent-threshold-boost=100 | FileCheck %s -check-prefix=TEST1
21 ; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=20 -unroll-max-percent-threshold-boost=200 | FileCheck %s -check-prefix=TEST2
22 ; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=20 -unroll-max-percent-threshold-boost=100 | FileCheck %s -check-prefix=TEST3
24 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop(unroll-full)' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=10 -unroll-max-percent-threshold-boost=100 | FileCheck %s -check-prefix=TEST1
25 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop(unroll-full)' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=20 -unroll-max-percent-threshold-boost=200 | FileCheck %s -check-prefix=TEST2
26 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop(unroll-full)' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=20 -unroll-max-percent-threshold-boost=100 | FileCheck %s -check-prefix=TEST3
28 ; Check that these work when the unroller has partial unrolling enabled too.
29 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,unroll' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=10 -unroll-max-percent-threshold-boost=100 | FileCheck %s -check-prefix=TEST1
30 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,unroll' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=20 -unroll-max-percent-threshold-boost=200 | FileCheck %s -check-prefix=TEST2
31 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,unroll' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=20 -unroll-max-percent-threshold-boost=100 | FileCheck %s -check-prefix=TEST3
33 ; If the absolute threshold is too low, we should not unroll:
34 ; TEST1: %array_const_idx = getelementptr inbounds [9 x i32], [9 x i32]* @known_constant, i64 0, i64 %iv
36 ; Otherwise, we should:
37 ; TEST2-NOT: %array_const_idx = getelementptr inbounds [9 x i32], [9 x i32]* @known_constant, i64 0, i64 %iv
39 ; If we do not boost threshold, the unroll will not happen:
40 ; TEST3: %array_const_idx = getelementptr inbounds [9 x i32], [9 x i32]* @known_constant, i64 0, i64 %iv
42 ; And check that we don't crash when we're not allowed to do any analysis.
43 ; RUN: opt < %s -loop-unroll -unroll-max-iteration-count-to-analyze=0 -disable-output
44 ; RUN: opt < %s -passes='require<opt-remark-emit>,loop(unroll-full)' -unroll-max-iteration-count-to-analyze=0 -disable-output
45 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
47 @known_constant = internal unnamed_addr constant [9 x i32] [i32 0, i32 -1, i32 0, i32 -1, i32 5, i32 -1, i32 0, i32 -1, i32 0], align 16
49 define i32 @foo(i32* noalias nocapture readonly %src) {
53 loop: ; preds = %loop, %entry
54 %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]
55 %r = phi i32 [ 0, %entry ], [ %add, %loop ]
56 %arrayidx = getelementptr inbounds i32, i32* %src, i64 %iv
57 %src_element = load i32, i32* %arrayidx, align 4
58 %array_const_idx = getelementptr inbounds [9 x i32], [9 x i32]* @known_constant, i64 0, i64 %iv
59 %const_array_element = load i32, i32* %array_const_idx, align 4
60 %mul = mul nsw i32 %src_element, %const_array_element
61 %add = add nsw i32 %mul, %r
62 %inc = add nuw nsw i64 %iv, 1
63 %exitcond86.i = icmp eq i64 %inc, 9
64 br i1 %exitcond86.i, label %loop.end, label %loop
66 loop.end: ; preds = %loop
67 %r.lcssa = phi i32 [ %r, %loop ]