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