; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s ; Function Attrs: nounwind uwtable define void @tail_dup_merge_loops(i32 %a, i8* %b, i8* %c) local_unnamed_addr #0 { ; CHECK-LABEL: tail_dup_merge_loops: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: jmp .LBB0_1 ; CHECK-NEXT: .p2align 4, 0x90 ; CHECK-NEXT: .LBB0_3: # %inner_loop_exit ; CHECK-NEXT: # in Loop: Header=BB0_1 Depth=1 ; CHECK-NEXT: incq %rsi ; CHECK-NEXT: .LBB0_1: # %outer_loop_top ; CHECK-NEXT: # =>This Loop Header: Depth=1 ; CHECK-NEXT: # Child Loop BB0_4 Depth 2 ; CHECK-NEXT: testl %edi, %edi ; CHECK-NEXT: je .LBB0_5 ; CHECK-NEXT: .p2align 4, 0x90 ; CHECK-NEXT: # %bb.2: # %inner_loop_top ; CHECK-NEXT: # in Loop: Header=BB0_1 Depth=1 ; CHECK-NEXT: cmpb $0, (%rsi) ; CHECK-NEXT: js .LBB0_3 ; CHECK-NEXT: .LBB0_4: # %inner_loop_latch ; CHECK-NEXT: # Parent Loop BB0_1 Depth=1 ; CHECK-NEXT: # => This Inner Loop Header: Depth=2 ; CHECK-NEXT: addq $2, %rsi ; CHECK-NEXT: cmpb $0, (%rsi) ; CHECK-NEXT: jns .LBB0_4 ; CHECK-NEXT: jmp .LBB0_3 ; CHECK-NEXT: .LBB0_5: # %exit ; CHECK-NEXT: retq entry: %notlhs674.i = icmp eq i32 %a, 0 br label %outer_loop_top outer_loop_top: ; preds = %inner_loop_exit, %entry %dst.0.ph.i = phi i8* [ %b, %entry ], [ %scevgep679.i, %inner_loop_exit ] br i1 %notlhs674.i, label %exit, label %inner_loop_preheader inner_loop_preheader: ; preds = %outer_loop_top br label %inner_loop_top inner_loop_top: ; preds = %inner_loop_latch, %inner_loop_preheader %dst.0.i = phi i8* [ %inc, %inner_loop_latch ], [ %dst.0.ph.i, %inner_loop_preheader ] %var = load i8, i8* %dst.0.i %tobool1.i = icmp slt i8 %var, 0 br label %inner_loop_test inner_loop_test: ; preds = %inner_loop_top br i1 %tobool1.i, label %inner_loop_exit, label %inner_loop_latch inner_loop_exit: ; preds = %inner_loop_test %scevgep.i = getelementptr i8, i8* %dst.0.i, i64 1 %scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 0 br label %outer_loop_top inner_loop_latch: ; preds = %inner_loop_test %cmp75.i = icmp ult i8* %dst.0.i, %c %inc = getelementptr i8, i8* %dst.0.i, i64 2 br label %inner_loop_top exit: ; preds = %outer_loop_top ret void } @.str.6 = external unnamed_addr constant [23 x i8], align 1 ; There is an erroneus check in LoopBase::addBasicBlockToLoop(), where it ; assumes that the header block for a loop is unique. ; For most of compilation this assumption is true, but during layout we allow ; this assumption to be violated. The following code will trigger the bug: ; The loops in question is eventually headed by the block shared_loop_header ; ; During layout The block labeled outer_loop_header gets tail-duplicated into ; outer_loop_latch, and into shared_preheader, and then removed. This leaves ; shared_loop_header as the header of both loops. The end result ; is that there are 2 valid loops, and that they share a header. If we re-ran ; the loop analysis, it would classify this as a single loop. ; So far this is fine as far as layout is concerned. ; After layout we tail merge blocks merge_other and merge_predecessor_split. ; We do this even though they share only a single instruction, because ; merge_predecessor_split falls through to their shared successor: ; outer_loop_latch. ; The rest of the blocks in the function are noise unfortunately. Bugpoint ; couldn't shrink the test any further. define i32 @loop_shared_header(i8* %exe, i32 %exesz, i32 %headsize, i32 %min, i32 %wwprva, i32 %e_lfanew, i8* readonly %wwp, i32 %wwpsz, i16 zeroext %sects) local_unnamed_addr #0 { ; CHECK-LABEL: loop_shared_header: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pushq %rbp ; CHECK-NEXT: pushq %r15 ; CHECK-NEXT: pushq %r14 ; CHECK-NEXT: pushq %r13 ; CHECK-NEXT: pushq %r12 ; CHECK-NEXT: pushq %rbx ; CHECK-NEXT: pushq %rax ; CHECK-NEXT: movl $1, %ebx ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: jne .LBB1_27 ; CHECK-NEXT: # %bb.1: # %if.end19 ; CHECK-NEXT: movl %esi, %r13d ; CHECK-NEXT: movq %rdi, %r12 ; CHECK-NEXT: movl (%rax), %ebp ; CHECK-NEXT: leal (,%rbp,4), %r14d ; CHECK-NEXT: movl %r14d, %r15d ; CHECK-NEXT: movl $1, %esi ; CHECK-NEXT: movq %r15, %rdi ; CHECK-NEXT: callq cli_calloc ; CHECK-NEXT: testl %r13d, %r13d ; CHECK-NEXT: je .LBB1_26 ; CHECK-NEXT: # %bb.2: # %if.end19 ; CHECK-NEXT: testl %ebp, %ebp ; CHECK-NEXT: je .LBB1_26 ; CHECK-NEXT: # %bb.3: # %if.end19 ; CHECK-NEXT: movq %rax, %rbx ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: jne .LBB1_26 ; CHECK-NEXT: # %bb.4: # %if.end19 ; CHECK-NEXT: cmpq %r12, %rbx ; CHECK-NEXT: jb .LBB1_26 ; CHECK-NEXT: # %bb.5: # %if.end50 ; CHECK-NEXT: movq %rbx, %rdi ; CHECK-NEXT: movq %r15, %rdx ; CHECK-NEXT: callq memcpy ; CHECK-NEXT: cmpl $4, %r14d ; CHECK-NEXT: jb .LBB1_29 ; CHECK-NEXT: # %bb.6: # %shared_preheader ; CHECK-NEXT: movb $32, %dl ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: # implicit-def: $rcx ; CHECK-NEXT: jmp .LBB1_9 ; CHECK-NEXT: .p2align 4, 0x90 ; CHECK-NEXT: .LBB1_7: # %merge_predecessor_split ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: movb $32, %dl ; CHECK-NEXT: xorl %esi, %esi ; CHECK-NEXT: .LBB1_8: # %outer_loop_latch ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: movzwl %si, %esi ; CHECK-NEXT: decl %esi ; CHECK-NEXT: movzwl %si, %esi ; CHECK-NEXT: leaq 1(%rcx,%rsi), %rcx ; CHECK-NEXT: .LBB1_9: # %outer_loop_header ; CHECK-NEXT: # =>This Loop Header: Depth=1 ; CHECK-NEXT: # Child Loop BB1_10 Depth 2 ; CHECK-NEXT: testl %ebp, %ebp ; CHECK-NEXT: je .LBB1_19 ; CHECK-NEXT: .p2align 4, 0x90 ; CHECK-NEXT: .LBB1_10: # %shared_loop_header ; CHECK-NEXT: # Parent Loop BB1_9 Depth=1 ; CHECK-NEXT: # => This Inner Loop Header: Depth=2 ; CHECK-NEXT: testq %rbx, %rbx ; CHECK-NEXT: jne .LBB1_28 ; CHECK-NEXT: # %bb.11: # %inner_loop_body ; CHECK-NEXT: # in Loop: Header=BB1_10 Depth=2 ; CHECK-NEXT: testl %eax, %eax ; CHECK-NEXT: jns .LBB1_10 ; CHECK-NEXT: # %bb.12: # %if.end96.i ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: cmpl $3, %ebp ; CHECK-NEXT: jae .LBB1_23 ; CHECK-NEXT: # %bb.13: # %if.end287.i ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: xorl %esi, %esi ; CHECK-NEXT: cmpl $1, %ebp ; CHECK-NEXT: setne %dl ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: jne .LBB1_17 ; CHECK-NEXT: # %bb.14: # %if.end308.i ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: je .LBB1_7 ; CHECK-NEXT: # %bb.15: # %if.end335.i ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: xorl %edx, %edx ; CHECK-NEXT: testb %dl, %dl ; CHECK-NEXT: movl $0, %esi ; CHECK-NEXT: jne .LBB1_8 ; CHECK-NEXT: # %bb.16: # %merge_other ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: xorl %esi, %esi ; CHECK-NEXT: jmp .LBB1_18 ; CHECK-NEXT: .p2align 4, 0x90 ; CHECK-NEXT: .LBB1_17: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: movb %dl, %sil ; CHECK-NEXT: addl $3, %esi ; CHECK-NEXT: .LBB1_18: # %outer_loop_latch ; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 ; CHECK-NEXT: # implicit-def: $dl ; CHECK-NEXT: jmp .LBB1_8 ; CHECK-NEXT: .LBB1_26: ; CHECK-NEXT: movl $1, %ebx ; CHECK-NEXT: jmp .LBB1_27 ; CHECK-NEXT: .LBB1_19: # %while.cond.us1412.i ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: testb %al, %al ; CHECK-NEXT: movl $1, %ebx ; CHECK-NEXT: jne .LBB1_21 ; CHECK-NEXT: # %bb.20: # %while.cond.us1412.i ; CHECK-NEXT: decb %dl ; CHECK-NEXT: jne .LBB1_27 ; CHECK-NEXT: .LBB1_21: # %if.end41.us1436.i ; CHECK-NEXT: .LBB1_23: # %if.then99.i ; CHECK-NEXT: movq .str.6@{{.*}}(%rip), %rdi ; CHECK-NEXT: xorl %ebx, %ebx ; CHECK-NEXT: xorl %eax, %eax ; CHECK-NEXT: callq cli_dbgmsg ; CHECK-NEXT: .LBB1_27: # %cleanup ; CHECK-NEXT: movl %ebx, %eax ; CHECK-NEXT: addq $8, %rsp ; CHECK-NEXT: popq %rbx ; CHECK-NEXT: popq %r12 ; CHECK-NEXT: popq %r13 ; CHECK-NEXT: popq %r14 ; CHECK-NEXT: popq %r15 ; CHECK-NEXT: popq %rbp ; CHECK-NEXT: retq ; CHECK-NEXT: .LBB1_28: # %wunpsect.exit.thread.loopexit389 ; CHECK-NEXT: .LBB1_29: # %wunpsect.exit.thread.loopexit391 entry: %0 = load i32, i32* undef, align 4 %mul = shl nsw i32 %0, 2 br i1 undef, label %if.end19, label %cleanup if.end19: ; preds = %entry %conv = zext i32 %mul to i64 %call = tail call i8* @cli_calloc(i64 %conv, i64 1) %1 = icmp eq i32 %exesz, 0 %notrhs = icmp eq i32 %0, 0 %or.cond117.not = or i1 %1, %notrhs %or.cond202 = or i1 %or.cond117.not, undef %cmp35 = icmp ult i8* %call, %exe %or.cond203 = or i1 %or.cond202, %cmp35 br i1 %or.cond203, label %cleanup, label %if.end50 if.end50: ; preds = %if.end19 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull %call, i8* undef, i64 %conv, i1 false) %cmp1.i.i = icmp ugt i32 %mul, 3 br i1 %cmp1.i.i, label %shared_preheader, label %wunpsect.exit.thread.loopexit391 shared_preheader: ; preds = %if.end50 br label %outer_loop_header outer_loop_header: ; preds = %outer_loop_latch, %shared_preheader %bits.1.i = phi i8 [ 32, %shared_preheader ], [ %bits.43.i, %outer_loop_latch ] %dst.0.ph.i = phi i8* [ undef, %shared_preheader ], [ %scevgep679.i, %outer_loop_latch ] %2 = icmp eq i32 %0, 0 br i1 %2, label %while.cond.us1412.i, label %shared_loop_header while.cond.us1412.i: ; preds = %outer_loop_header %.pre.i = add i8 %bits.1.i, -1 %tobool2.us1420.i = icmp eq i8 %.pre.i, 0 %or.cond.us1421.i = or i1 undef, %tobool2.us1420.i br i1 %or.cond.us1421.i, label %if.end41.us1436.i, label %cleanup if.end41.us1436.i: ; preds = %while.cond.us1412.i unreachable shared_loop_header: ; preds = %dup_early2, %dup_early1 %dst.0.i = phi i8* [ undef, %inner_loop_body ], [ %dst.0.ph.i, %outer_loop_header ], [ undef, %dead_block ] %cmp3.i1172.i = icmp ult i8* null, %call br i1 %cmp3.i1172.i, label %wunpsect.exit.thread.loopexit389, label %inner_loop_body inner_loop_body: ; preds = %shared_loop_header %3 = icmp slt i32 undef, 0 br i1 %3, label %if.end96.i, label %shared_loop_header dead_block: ; preds = %inner_loop_body %cmp75.i = icmp ult i8* %dst.0.i, null br label %shared_loop_header if.end96.i: ; preds = %inner_loop_body %cmp97.i = icmp ugt i32 %0, 2 br i1 %cmp97.i, label %if.then99.i, label %if.end287.i if.then99.i: ; preds = %if.end96.i tail call void (i8*, ...) @cli_dbgmsg(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.6, i64 0, i64 0), i32 undef) br label %cleanup if.end287.i: ; preds = %if.end96.i %cmp291.i = icmp ne i32 %0, 1 %conv294.i = select i1 %cmp291.i, i16 4, i16 3 br i1 undef, label %if.end308.i, label %outer_loop_latch if.end308.i: ; preds = %if.end287.i br i1 undef, label %if.end335.i, label %merge_predecessor_split merge_predecessor_split: ; preds = %if.end308.i %4 = bitcast i8* undef to i32* br label %outer_loop_latch if.end335.i: ; preds = %if.end308.i br i1 undef, label %outer_loop_latch, label %merge_other merge_other: ; preds = %if.end335.i br label %outer_loop_latch outer_loop_latch: ; preds = %merge_other, %if.end335.i, %merge_predecessor_split, %if.end287.i %bits.43.i = phi i8 [ undef, %if.end287.i ], [ undef, %merge_other ], [ 32, %merge_predecessor_split ], [ 0, %if.end335.i ] %backsize.0.i = phi i16 [ %conv294.i, %if.end287.i ], [ 0, %merge_other ], [ 0, %merge_predecessor_split ], [ 0, %if.end335.i ] %5 = add i16 %backsize.0.i, -1 %6 = zext i16 %5 to i64 %scevgep.i = getelementptr i8, i8* %dst.0.ph.i, i64 1 %scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 %6 br label %outer_loop_header wunpsect.exit.thread.loopexit389: ; preds = %shared_loop_header unreachable wunpsect.exit.thread.loopexit391: ; preds = %if.end50 unreachable cleanup: ; preds = %if.then99.i, %while.cond.us1412.i, %if.end19, %entry %retval.0 = phi i32 [ 0, %if.then99.i ], [ 1, %entry ], [ 1, %if.end19 ], [ 1, %while.cond.us1412.i ] ret i32 %retval.0 } ; Function Attrs: nounwind declare void @cli_dbgmsg(i8*, ...) local_unnamed_addr #0 ; Function Attrs: nounwind declare i8* @cli_calloc(i64, i64) local_unnamed_addr #0 ; Function Attrs: argmemonly nounwind declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i1) #1 attributes #0 = { nounwind } attributes #1 = { argmemonly nounwind }