| Nick Lewycky | 89d093d | 2011-11-09 07:11:37 +0000 | [diff] [blame] | 1 | ; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s |
| 2 | |
| 3 | ; CHECK: Determining loop execution counts for: @test |
| 4 | ; CHECK: Loop %for.body: backedge-taken count is ((-2 + %len) /u 2) |
| 5 | ; CHECK: Loop %for.body: max backedge-taken count is 1073741823 |
| 6 | |
| 7 | define zeroext i16 @test(i16* nocapture %p, i32 %len) nounwind readonly { |
| 8 | entry: |
| 9 | %cmp2 = icmp sgt i32 %len, 1 |
| 10 | br i1 %cmp2, label %for.body.preheader, label %for.end |
| 11 | |
| 12 | for.body.preheader: ; preds = %entry |
| 13 | br label %for.body |
| 14 | |
| 15 | for.body: ; preds = %for.body, %for.body.preheader |
| 16 | %p.addr.05 = phi i16* [ %incdec.ptr, %for.body ], [ %p, %for.body.preheader ] |
| 17 | %len.addr.04 = phi i32 [ %sub, %for.body ], [ %len, %for.body.preheader ] |
| 18 | %res.03 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ] |
| 19 | %incdec.ptr = getelementptr inbounds i16* %p.addr.05, i32 1 |
| 20 | %0 = load i16* %p.addr.05, align 2 |
| 21 | %conv = zext i16 %0 to i32 |
| 22 | %add = add i32 %conv, %res.03 |
| 23 | %sub = add nsw i32 %len.addr.04, -2 |
| 24 | %cmp = icmp sgt i32 %sub, 1 |
| 25 | br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge |
| 26 | |
| 27 | for.cond.for.end_crit_edge: ; preds = %for.body |
| 28 | %extract.t = trunc i32 %add to i16 |
| 29 | br label %for.end |
| 30 | |
| 31 | for.end: ; preds = %for.cond.for.end_crit_edge, %entry |
| 32 | %res.0.lcssa.off0 = phi i16 [ %extract.t, %for.cond.for.end_crit_edge ], [ 0, %entry ] |
| 33 | ret i16 %res.0.lcssa.off0 |
| 34 | } |
| 35 | |