xref: /llvm-project/llvm/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll (revision 864bb84a427de367528d15270790dd152871daf2)
1; RUN: opt < %s -passes='loop(indvars),instcombine' -S | FileCheck %s
2;
3; Test that -passes=indvars can reduce variable stride IVs.  If it can reduce variable
4; stride iv's, it will make %iv. and %m.0.0 isomorphic to each other without
5; cycles, allowing the tmp.21 subtraction to be eliminated.
6
7define void @vnum_test8(ptr %data) {
8entry:
9        %tmp.1 = getelementptr i32, ptr %data, i32 3                ; <ptr> [#uses=1]
10        %tmp.2 = load i32, ptr %tmp.1               ; <i32> [#uses=2]
11        %tmp.4 = getelementptr i32, ptr %data, i32 4                ; <ptr> [#uses=1]
12        %tmp.5 = load i32, ptr %tmp.4               ; <i32> [#uses=2]
13        %tmp.8 = getelementptr i32, ptr %data, i32 2                ; <ptr> [#uses=1]
14        %tmp.9 = load i32, ptr %tmp.8               ; <i32> [#uses=3]
15        %tmp.125 = icmp sgt i32 %tmp.2, 0               ; <i1> [#uses=1]
16        br i1 %tmp.125, label %no_exit.preheader, label %return
17
18no_exit.preheader:              ; preds = %entry
19        %tmp.16 = getelementptr i32, ptr %data, i32 %tmp.9          ; <ptr> [#uses=1]
20        br label %no_exit
21
22; CHECK: store i32 0
23no_exit:                ; preds = %no_exit, %no_exit.preheader
24        %iv.ui = phi i32 [ 0, %no_exit.preheader ], [ %iv..inc.ui, %no_exit ]           ; <i32> [#uses=1]
25        %iv. = phi i32 [ %tmp.5, %no_exit.preheader ], [ %iv..inc, %no_exit ]           ; <i32> [#uses=2]
26        %m.0.0 = phi i32 [ %tmp.5, %no_exit.preheader ], [ %tmp.24, %no_exit ]          ; <i32> [#uses=2]
27        store i32 2, ptr %tmp.16
28        %tmp.21 = sub i32 %m.0.0, %iv.          ; <i32> [#uses=1]
29        store i32 %tmp.21, ptr %data
30        %tmp.24 = add i32 %m.0.0, %tmp.9                ; <i32> [#uses=1]
31        %iv..inc = add i32 %tmp.9, %iv.         ; <i32> [#uses=1]
32        %iv..inc.ui = add i32 %iv.ui, 1         ; <i32> [#uses=2]
33        %iv..inc1 = bitcast i32 %iv..inc.ui to i32              ; <i32> [#uses=1]
34        %tmp.12 = icmp slt i32 %iv..inc1, %tmp.2                ; <i1> [#uses=1]
35        br i1 %tmp.12, label %no_exit, label %return.loopexit
36
37return.loopexit:                ; preds = %no_exit
38        br label %return
39
40return:         ; preds = %return.loopexit, %entry
41        ret void
42}
43
44