1 ; RUN: opt < %s -indvars -disable-iv-rewrite -S | FileCheck %s
3 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
5 ; Tests sign extend elimination in the inner and outer loop.
6 ; %outercount is straightforward to widen, besides being in an outer loop.
7 ; %innercount is currently blocked by lcssa, so is not widened.
8 ; %inneriv can be widened only after proving it has no signed-overflow
9 ; based on the loop test.
10 define void @nestedIV(i8* %address, i32 %limit) nounwind {
12 %limitdec = add i32 %limit, -1
17 ; Eliminate %ofs1 after widening outercount.
19 ; CHECK: getelementptr
21 ; IV rewriting hoists a gep into this block. We don't like that.
22 ; CHECK-NOT: getelementptr
24 %outercount = phi i32 [ %outerpostcount, %outermerge ], [ 0, %entry ]
25 %innercount = phi i32 [ %innercount.merge, %outermerge ], [ 0, %entry ]
27 %outercountdec = add i32 %outercount, -1
28 %ofs1 = sext i32 %outercountdec to i64
29 %adr1 = getelementptr i8* %address, i64 %ofs1
32 br label %innerpreheader
35 %innerprecmp = icmp sgt i32 %limitdec, %innercount
36 br i1 %innerprecmp, label %innerloop, label %outermerge
40 ; Eliminate %ofs2 after widening inneriv.
42 ; CHECK: getelementptr
44 ; FIXME: We should not increase the number of IVs in this loop.
45 ; sext elimination plus LFTR results in 3 final IVs.
47 ; FIXME: eliminate %ofs3 based the loop pre/post conditions
48 ; even though innerpostiv is not NSW, thus sign extending innerpostiv
49 ; does not yield the same expression as incrementing the widened inneriv.
51 %inneriv = phi i32 [ %innerpostiv, %innerloop ], [ %innercount, %innerpreheader ]
52 %innerpostiv = add i32 %inneriv, 1
54 %ofs2 = sext i32 %inneriv to i64
55 %adr2 = getelementptr i8* %address, i64 %ofs2
58 %ofs3 = sext i32 %innerpostiv to i64
59 %adr3 = getelementptr i8* %address, i64 %ofs3
62 %innercmp = icmp sgt i32 %limitdec, %innerpostiv
63 br i1 %innercmp, label %innerloop, label %innerexit
66 %innercount.lcssa = phi i32 [ %innerpostiv, %innerloop ]
71 ; Eliminate %ofs4 after widening outercount
73 ; CHECK: getelementptr
75 ; TODO: Eliminate %ofs5 after removing lcssa
77 %innercount.merge = phi i32 [ %innercount.lcssa, %innerexit ], [ %innercount, %innerpreheader ]
79 %ofs4 = sext i32 %outercount to i64
80 %adr4 = getelementptr i8* %address, i64 %ofs4
83 %ofs5 = sext i32 %innercount.merge to i64
84 %adr5 = getelementptr i8* %address, i64 %ofs5
87 %outerpostcount = add i32 %outercount, 1
88 %tmp47 = icmp slt i32 %outerpostcount, %limit
89 br i1 %tmp47, label %outerloop, label %return