1; RUN: llc -march=mips -mcpu=mips32r6 -O1 -start-after=dwarfehprepare < %s | FileCheck %s
2
3; beqc/bnec have the constraint that $rs < $rt && $rs != 0 && $rt != 0
4; Cases where $rs == 0 and $rt != 0 should be transformed into beqzc/bnezc.
5; Cases where $rs > $rt can have the operands swapped as ==,!= are commutative.
6
7; Cases where beq & bne where $rs == $rt have to inhibited from being turned
8; into compact branches but arguably should not occur. This test covers the
9; $rs == $rt case.
10
11; Starting from dwarf exception handling preparation skips optimizations that
12; may simplify out the crucical bnec $4, $4 instruction.
13
14define internal void @_ZL14TestRemoveLastv(i32* %alist.sroa.0.4) {
15entry:
16  %ascevgep = getelementptr i32, i32* %alist.sroa.0.4, i64 99
17  br label %do.body121
18
19for.cond117:
20  %alsr.iv.next = add nsw i32 %alsr.iv, -1
21  %ascevgep340 = getelementptr i32, i32* %alsr.iv339, i64 -1
22  %acmp118 = icmp sgt i32 %alsr.iv.next, 0
23  br i1 %acmp118, label %do.body121, label %if.then143
24
25do.body121:
26  %alsr.iv339 = phi i32* [ %ascevgep, %entry ], [ %ascevgep340, %for.cond117 ]
27  %alsr.iv = phi i32 [ 100, %entry ], [ %alsr.iv.next, %for.cond117 ]
28  %a9 = add i32 %alsr.iv, -1
29  %alnot124 = icmp eq i32 %alsr.iv, %alsr.iv
30  br i1 %alnot124, label %do.body134, label %if.then143, !prof !11
31
32do.body134:
33  %a10 = add i32 %alsr.iv, -1
34  %a11 = load i32, i32* %alsr.iv339, align 4, !tbaa !5
35; CHECK-NOT: bnec $[[R0:[0-9]+]], $[[R0]]
36; CHECK-NOT: beqc $[[R1:[0-9]+]], $[[R1]]
37  %alnot137 = icmp eq i32 %a9, %a11
38  br i1 %alnot137, label %do.end146, label %if.then143, !prof !11
39
40if.then143:
41 ret void
42 unreachable
43
44do.end146:
45  %alnot151 = icmp eq i32 %a9, %a10
46  br i1 %alnot151, label %for.cond117, label %if.then143, !prof !11
47
48}
49!3 = !{!"omnipotent char", !4, i64 0}
50!4 = !{!"Simple C++ TBAA"}
51!5 = !{!6, !6, i64 0}
52!6 = !{!"int", !3, i64 0}
53!11 = !{!"branch_weights", i32 2000, i32 1}
54!12 = !{!"branch_weights", i32 -388717296, i32 7818360}
55
56