1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py 2; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s 3 4; Function Attrs: nounwind uwtable 5define void @tail_dup_merge_loops(i32 %a, i8* %b, i8* %c) local_unnamed_addr #0 { 6; CHECK-LABEL: tail_dup_merge_loops: 7; CHECK: # %bb.0: # %entry 8; CHECK-NEXT: testl %edi, %edi 9; CHECK-NEXT: jne .LBB0_2 10; CHECK-NEXT: jmp .LBB0_5 11; CHECK-NEXT: .LBB0_3: # %inner_loop_exit 12; CHECK-NEXT: # in Loop: Header=BB0_2 Depth=1 13; CHECK-NEXT: incq %rsi 14; CHECK-NEXT: testl %edi, %edi 15; CHECK-NEXT: je .LBB0_5 16; CHECK-NEXT: .p2align 4, 0x90 17; CHECK-NEXT: .LBB0_2: # %inner_loop_top 18; CHECK-NEXT: # =>This Loop Header: Depth=1 19; CHECK-NEXT: # Child Loop BB0_4 Depth 2 20; CHECK-NEXT: cmpb $0, (%rsi) 21; CHECK-NEXT: js .LBB0_3 22; CHECK-NEXT: .LBB0_4: # %inner_loop_latch 23; CHECK-NEXT: # Parent Loop BB0_2 Depth=1 24; CHECK-NEXT: # => This Inner Loop Header: Depth=2 25; CHECK-NEXT: addq $2, %rsi 26; CHECK-NEXT: cmpb $0, (%rsi) 27; CHECK-NEXT: jns .LBB0_4 28; CHECK-NEXT: jmp .LBB0_3 29; CHECK-NEXT: .LBB0_5: # %exit 30; CHECK-NEXT: retq 31entry: 32 %notlhs674.i = icmp eq i32 %a, 0 33 br label %outer_loop_top 34 35outer_loop_top: ; preds = %inner_loop_exit, %entry 36 %dst.0.ph.i = phi i8* [ %b, %entry ], [ %scevgep679.i, %inner_loop_exit ] 37 br i1 %notlhs674.i, label %exit, label %inner_loop_preheader 38 39inner_loop_preheader: ; preds = %outer_loop_top 40 br label %inner_loop_top 41 42inner_loop_top: ; preds = %inner_loop_latch, %inner_loop_preheader 43 %dst.0.i = phi i8* [ %inc, %inner_loop_latch ], [ %dst.0.ph.i, %inner_loop_preheader ] 44 %var = load i8, i8* %dst.0.i 45 %tobool1.i = icmp slt i8 %var, 0 46 br label %inner_loop_test 47 48inner_loop_test: ; preds = %inner_loop_top 49 br i1 %tobool1.i, label %inner_loop_exit, label %inner_loop_latch 50 51inner_loop_exit: ; preds = %inner_loop_test 52 %scevgep.i = getelementptr i8, i8* %dst.0.i, i64 1 53 %scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 0 54 br label %outer_loop_top 55 56inner_loop_latch: ; preds = %inner_loop_test 57 %cmp75.i = icmp ult i8* %dst.0.i, %c 58 %inc = getelementptr i8, i8* %dst.0.i, i64 2 59 br label %inner_loop_top 60 61exit: ; preds = %outer_loop_top 62 ret void 63} 64 65@.str.6 = external unnamed_addr constant [23 x i8], align 1 66 67; There is an erroneus check in LoopBase::addBasicBlockToLoop(), where it 68; assumes that the header block for a loop is unique. 69; For most of compilation this assumption is true, but during layout we allow 70; this assumption to be violated. The following code will trigger the bug: 71 72; The loops in question is eventually headed by the block shared_loop_header 73; 74; During layout The block labeled outer_loop_header gets tail-duplicated into 75; outer_loop_latch, and into shared_preheader, and then removed. This leaves 76; shared_loop_header as the header of both loops. The end result 77; is that there are 2 valid loops, and that they share a header. If we re-ran 78; the loop analysis, it would classify this as a single loop. 79; So far this is fine as far as layout is concerned. 80; After layout we tail merge blocks merge_other and merge_predecessor_split. 81; We do this even though they share only a single instruction, because 82; merge_predecessor_split falls through to their shared successor: 83; outer_loop_latch. 84; The rest of the blocks in the function are noise unfortunately. Bugpoint 85; couldn't shrink the test any further. 86 87define 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 { 88; CHECK-LABEL: loop_shared_header: 89; CHECK: # %bb.0: # %entry 90; CHECK-NEXT: pushq %rbp 91; CHECK-NEXT: pushq %r15 92; CHECK-NEXT: pushq %r14 93; CHECK-NEXT: pushq %r13 94; CHECK-NEXT: pushq %r12 95; CHECK-NEXT: pushq %rbx 96; CHECK-NEXT: pushq %rax 97; CHECK-NEXT: movl $1, %ebx 98; CHECK-NEXT: xorl %eax, %eax 99; CHECK-NEXT: testb %al, %al 100; CHECK-NEXT: jne .LBB1_26 101; CHECK-NEXT: # %bb.1: # %if.end19 102; CHECK-NEXT: movl %esi, %r13d 103; CHECK-NEXT: movq %rdi, %r12 104; CHECK-NEXT: movl (%rax), %ebp 105; CHECK-NEXT: leal (,%rbp,4), %r14d 106; CHECK-NEXT: movl %r14d, %r15d 107; CHECK-NEXT: movl $1, %esi 108; CHECK-NEXT: movq %r15, %rdi 109; CHECK-NEXT: callq cli_calloc 110; CHECK-NEXT: testl %r13d, %r13d 111; CHECK-NEXT: je .LBB1_25 112; CHECK-NEXT: # %bb.2: # %if.end19 113; CHECK-NEXT: testl %ebp, %ebp 114; CHECK-NEXT: je .LBB1_25 115; CHECK-NEXT: # %bb.3: # %if.end19 116; CHECK-NEXT: movq %rax, %rbx 117; CHECK-NEXT: xorl %eax, %eax 118; CHECK-NEXT: testb %al, %al 119; CHECK-NEXT: jne .LBB1_25 120; CHECK-NEXT: # %bb.4: # %if.end19 121; CHECK-NEXT: cmpq %r12, %rbx 122; CHECK-NEXT: jb .LBB1_25 123; CHECK-NEXT: # %bb.5: # %if.end50 124; CHECK-NEXT: movq %rbx, %rdi 125; CHECK-NEXT: movq %r15, %rdx 126; CHECK-NEXT: callq memcpy 127; CHECK-NEXT: cmpl $4, %r14d 128; CHECK-NEXT: jb .LBB1_28 129; CHECK-NEXT: # %bb.6: # %shared_preheader 130; CHECK-NEXT: movb $32, %dl 131; CHECK-NEXT: xorl %eax, %eax 132; CHECK-NEXT: # implicit-def: $rcx 133; CHECK-NEXT: testl %ebp, %ebp 134; CHECK-NEXT: je .LBB1_18 135; CHECK-NEXT: .p2align 4, 0x90 136; CHECK-NEXT: .LBB1_9: # %shared_loop_header 137; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 138; CHECK-NEXT: testq %rbx, %rbx 139; CHECK-NEXT: jne .LBB1_27 140; CHECK-NEXT: # %bb.10: # %inner_loop_body 141; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 142; CHECK-NEXT: testl %eax, %eax 143; CHECK-NEXT: jns .LBB1_9 144; CHECK-NEXT: # %bb.11: # %if.end96.i 145; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 146; CHECK-NEXT: cmpl $3, %ebp 147; CHECK-NEXT: jae .LBB1_22 148; CHECK-NEXT: # %bb.12: # %if.end287.i 149; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 150; CHECK-NEXT: xorl %esi, %esi 151; CHECK-NEXT: cmpl $1, %ebp 152; CHECK-NEXT: setne %dl 153; CHECK-NEXT: testb %al, %al 154; CHECK-NEXT: jne .LBB1_16 155; CHECK-NEXT: # %bb.13: # %if.end308.i 156; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 157; CHECK-NEXT: testb %al, %al 158; CHECK-NEXT: je .LBB1_7 159; CHECK-NEXT: # %bb.14: # %if.end335.i 160; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 161; CHECK-NEXT: xorl %edx, %edx 162; CHECK-NEXT: testb %dl, %dl 163; CHECK-NEXT: movl $0, %esi 164; CHECK-NEXT: jne .LBB1_8 165; CHECK-NEXT: # %bb.15: # %merge_other 166; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 167; CHECK-NEXT: xorl %esi, %esi 168; CHECK-NEXT: jmp .LBB1_17 169; CHECK-NEXT: .LBB1_16: # in Loop: Header=BB1_9 Depth=1 170; CHECK-NEXT: movb %dl, %sil 171; CHECK-NEXT: addl $3, %esi 172; CHECK-NEXT: .LBB1_17: # %outer_loop_latch 173; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 174; CHECK-NEXT: # implicit-def: $dl 175; CHECK-NEXT: jmp .LBB1_8 176; CHECK-NEXT: .LBB1_7: # %merge_predecessor_split 177; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 178; CHECK-NEXT: movb $32, %dl 179; CHECK-NEXT: xorl %esi, %esi 180; CHECK-NEXT: .LBB1_8: # %outer_loop_latch 181; CHECK-NEXT: # in Loop: Header=BB1_9 Depth=1 182; CHECK-NEXT: movzwl %si, %esi 183; CHECK-NEXT: decl %esi 184; CHECK-NEXT: movzwl %si, %esi 185; CHECK-NEXT: leaq 1(%rcx,%rsi), %rcx 186; CHECK-NEXT: testl %ebp, %ebp 187; CHECK-NEXT: jne .LBB1_9 188; CHECK-NEXT: .LBB1_18: # %while.cond.us1412.i 189; CHECK-NEXT: xorl %eax, %eax 190; CHECK-NEXT: testb %al, %al 191; CHECK-NEXT: movl $1, %ebx 192; CHECK-NEXT: jne .LBB1_20 193; CHECK-NEXT: # %bb.19: # %while.cond.us1412.i 194; CHECK-NEXT: decb %dl 195; CHECK-NEXT: jne .LBB1_26 196; CHECK-NEXT: .LBB1_20: # %if.end41.us1436.i 197; CHECK-NEXT: .LBB1_25: 198; CHECK-NEXT: movl $1, %ebx 199; CHECK-NEXT: jmp .LBB1_26 200; CHECK-NEXT: .LBB1_22: # %if.then99.i 201; CHECK-NEXT: xorl %ebx, %ebx 202; CHECK-NEXT: movl $.str.6, %edi 203; CHECK-NEXT: xorl %eax, %eax 204; CHECK-NEXT: callq cli_dbgmsg 205; CHECK-NEXT: .LBB1_26: # %cleanup 206; CHECK-NEXT: movl %ebx, %eax 207; CHECK-NEXT: addq $8, %rsp 208; CHECK-NEXT: popq %rbx 209; CHECK-NEXT: popq %r12 210; CHECK-NEXT: popq %r13 211; CHECK-NEXT: popq %r14 212; CHECK-NEXT: popq %r15 213; CHECK-NEXT: popq %rbp 214; CHECK-NEXT: retq 215; CHECK-NEXT: .LBB1_27: # %wunpsect.exit.thread.loopexit389 216; CHECK-NEXT: .LBB1_28: # %wunpsect.exit.thread.loopexit391 217entry: 218 %0 = load i32, i32* undef, align 4 219 %mul = shl nsw i32 %0, 2 220 br i1 undef, label %if.end19, label %cleanup 221 222if.end19: ; preds = %entry 223 %conv = zext i32 %mul to i64 224 %call = tail call i8* @cli_calloc(i64 %conv, i64 1) 225 %1 = icmp eq i32 %exesz, 0 226 %notrhs = icmp eq i32 %0, 0 227 %or.cond117.not = or i1 %1, %notrhs 228 %or.cond202 = or i1 %or.cond117.not, undef 229 %cmp35 = icmp ult i8* %call, %exe 230 %or.cond203 = or i1 %or.cond202, %cmp35 231 br i1 %or.cond203, label %cleanup, label %if.end50 232 233if.end50: ; preds = %if.end19 234 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull %call, i8* undef, i64 %conv, i1 false) 235 %cmp1.i.i = icmp ugt i32 %mul, 3 236 br i1 %cmp1.i.i, label %shared_preheader, label %wunpsect.exit.thread.loopexit391 237 238shared_preheader: ; preds = %if.end50 239 br label %outer_loop_header 240 241outer_loop_header: ; preds = %outer_loop_latch, %shared_preheader 242 %bits.1.i = phi i8 [ 32, %shared_preheader ], [ %bits.43.i, %outer_loop_latch ] 243 %dst.0.ph.i = phi i8* [ undef, %shared_preheader ], [ %scevgep679.i, %outer_loop_latch ] 244 %2 = icmp eq i32 %0, 0 245 br i1 %2, label %while.cond.us1412.i, label %shared_loop_header 246 247while.cond.us1412.i: ; preds = %outer_loop_header 248 %.pre.i = add i8 %bits.1.i, -1 249 %tobool2.us1420.i = icmp eq i8 %.pre.i, 0 250 %or.cond.us1421.i = or i1 undef, %tobool2.us1420.i 251 br i1 %or.cond.us1421.i, label %if.end41.us1436.i, label %cleanup 252 253if.end41.us1436.i: ; preds = %while.cond.us1412.i 254 unreachable 255 256shared_loop_header: ; preds = %dup_early2, %dup_early1 257 %dst.0.i = phi i8* [ undef, %inner_loop_body ], [ %dst.0.ph.i, %outer_loop_header ], [ undef, %dead_block ] 258 %cmp3.i1172.i = icmp ult i8* null, %call 259 br i1 %cmp3.i1172.i, label %wunpsect.exit.thread.loopexit389, label %inner_loop_body 260 261inner_loop_body: ; preds = %shared_loop_header 262 %3 = icmp slt i32 undef, 0 263 br i1 %3, label %if.end96.i, label %shared_loop_header 264 265dead_block: ; preds = %inner_loop_body 266 %cmp75.i = icmp ult i8* %dst.0.i, null 267 br label %shared_loop_header 268 269if.end96.i: ; preds = %inner_loop_body 270 %cmp97.i = icmp ugt i32 %0, 2 271 br i1 %cmp97.i, label %if.then99.i, label %if.end287.i 272 273if.then99.i: ; preds = %if.end96.i 274 tail call void (i8*, ...) @cli_dbgmsg(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.6, i64 0, i64 0), i32 undef) 275 br label %cleanup 276 277if.end287.i: ; preds = %if.end96.i 278 %cmp291.i = icmp ne i32 %0, 1 279 %conv294.i = select i1 %cmp291.i, i16 4, i16 3 280 br i1 undef, label %if.end308.i, label %outer_loop_latch 281 282if.end308.i: ; preds = %if.end287.i 283 br i1 undef, label %if.end335.i, label %merge_predecessor_split 284 285merge_predecessor_split: ; preds = %if.end308.i 286 %4 = bitcast i8* undef to i32* 287 br label %outer_loop_latch 288 289if.end335.i: ; preds = %if.end308.i 290 br i1 undef, label %outer_loop_latch, label %merge_other 291 292merge_other: ; preds = %if.end335.i 293 br label %outer_loop_latch 294 295outer_loop_latch: ; preds = %merge_other, %if.end335.i, %merge_predecessor_split, %if.end287.i 296 %bits.43.i = phi i8 [ undef, %if.end287.i ], [ undef, %merge_other ], [ 32, %merge_predecessor_split ], [ 0, %if.end335.i ] 297 %backsize.0.i = phi i16 [ %conv294.i, %if.end287.i ], [ 0, %merge_other ], [ 0, %merge_predecessor_split ], [ 0, %if.end335.i ] 298 %5 = add i16 %backsize.0.i, -1 299 %6 = zext i16 %5 to i64 300 %scevgep.i = getelementptr i8, i8* %dst.0.ph.i, i64 1 301 %scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 %6 302 br label %outer_loop_header 303 304wunpsect.exit.thread.loopexit389: ; preds = %shared_loop_header 305 unreachable 306 307wunpsect.exit.thread.loopexit391: ; preds = %if.end50 308 unreachable 309 310cleanup: ; preds = %if.then99.i, %while.cond.us1412.i, %if.end19, %entry 311 %retval.0 = phi i32 [ 0, %if.then99.i ], [ 1, %entry ], [ 1, %if.end19 ], [ 1, %while.cond.us1412.i ] 312 ret i32 %retval.0 313} 314 315; Function Attrs: nounwind 316declare void @cli_dbgmsg(i8*, ...) local_unnamed_addr #0 317 318; Function Attrs: nounwind 319declare i8* @cli_calloc(i64, i64) local_unnamed_addr #0 320 321; Function Attrs: argmemonly nounwind 322declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i1) #1 323attributes #0 = { nounwind } 324attributes #1 = { argmemonly nounwind } 325