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: jne .LBB0_2 16; CHECK-NEXT: jmp .LBB0_5 17; CHECK-NEXT: .p2align 4, 0x90 18; CHECK-NEXT: .LBB0_4: # %inner_loop_latch 19; CHECK-NEXT: # in Loop: Header=BB0_2 Depth=1 20; CHECK-NEXT: addq $2, %rsi 21; CHECK-NEXT: .LBB0_2: # %inner_loop_top 22; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 23; CHECK-NEXT: cmpb $0, (%rsi) 24; CHECK-NEXT: jns .LBB0_4 25; CHECK-NEXT: jmp .LBB0_3 26; CHECK-NEXT: .LBB0_5: # %exit 27; CHECK-NEXT: retq 28entry: 29 %notlhs674.i = icmp eq i32 %a, 0 30 br label %outer_loop_top 31 32outer_loop_top: ; preds = %inner_loop_exit, %entry 33 %dst.0.ph.i = phi i8* [ %b, %entry ], [ %scevgep679.i, %inner_loop_exit ] 34 br i1 %notlhs674.i, label %exit, label %inner_loop_preheader 35 36inner_loop_preheader: ; preds = %outer_loop_top 37 br label %inner_loop_top 38 39inner_loop_top: ; preds = %inner_loop_latch, %inner_loop_preheader 40 %dst.0.i = phi i8* [ %inc, %inner_loop_latch ], [ %dst.0.ph.i, %inner_loop_preheader ] 41 %var = load i8, i8* %dst.0.i 42 %tobool1.i = icmp slt i8 %var, 0 43 br label %inner_loop_test 44 45inner_loop_test: ; preds = %inner_loop_top 46 br i1 %tobool1.i, label %inner_loop_exit, label %inner_loop_latch 47 48inner_loop_exit: ; preds = %inner_loop_test 49 %scevgep.i = getelementptr i8, i8* %dst.0.i, i64 1 50 %scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 0 51 br label %outer_loop_top 52 53inner_loop_latch: ; preds = %inner_loop_test 54 %cmp75.i = icmp ult i8* %dst.0.i, %c 55 %inc = getelementptr i8, i8* %dst.0.i, i64 2 56 br label %inner_loop_top 57 58exit: ; preds = %outer_loop_top 59 ret void 60} 61 62@.str.6 = external unnamed_addr constant [23 x i8], align 1 63 64; There is an erroneus check in LoopBase::addBasicBlockToLoop(), where it 65; assumes that the header block for a loop is unique. 66; For most of compilation this assumption is true, but during layout we allow 67; this assumption to be violated. The following code will trigger the bug: 68 69; The loops in question is eventually headed by the block shared_loop_header 70; 71; During layout The block labeled outer_loop_header gets tail-duplicated into 72; outer_loop_latch, and into shared_preheader, and then removed. This leaves 73; shared_loop_header as the header of both loops. The end result 74; is that there are 2 valid loops, and that they share a header. If we re-ran 75; the loop analysis, it would classify this as a single loop. 76; So far this is fine as far as layout is concerned. 77; After layout we tail merge blocks merge_other and merge_predecessor_split. 78; We do this even though they share only a single instruction, because 79; merge_predecessor_split falls through to their shared successor: 80; outer_loop_latch. 81; The rest of the blocks in the function are noise unfortunately. Bugpoint 82; couldn't shrink the test any further. 83 84define 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 { 85; CHECK-LABEL: loop_shared_header: 86; CHECK: # %bb.0: # %entry 87; CHECK-NEXT: pushq %rbp 88; CHECK-NEXT: pushq %r15 89; CHECK-NEXT: pushq %r14 90; CHECK-NEXT: pushq %r13 91; CHECK-NEXT: pushq %r12 92; CHECK-NEXT: pushq %rbx 93; CHECK-NEXT: pushq %rax 94; CHECK-NEXT: movl $1, %ebx 95; CHECK-NEXT: xorl %eax, %eax 96; CHECK-NEXT: testb %al, %al 97; CHECK-NEXT: jne .LBB1_26 98; CHECK-NEXT: # %bb.1: # %if.end19 99; CHECK-NEXT: movl %esi, %r13d 100; CHECK-NEXT: movq %rdi, %r12 101; CHECK-NEXT: movl (%rax), %ebp 102; CHECK-NEXT: leal (,%rbp,4), %r14d 103; CHECK-NEXT: movl %r14d, %r15d 104; CHECK-NEXT: movl $1, %esi 105; CHECK-NEXT: movq %r15, %rdi 106; CHECK-NEXT: callq cli_calloc 107; CHECK-NEXT: testl %r13d, %r13d 108; CHECK-NEXT: je .LBB1_25 109; CHECK-NEXT: # %bb.2: # %if.end19 110; CHECK-NEXT: testl %ebp, %ebp 111; CHECK-NEXT: je .LBB1_25 112; CHECK-NEXT: # %bb.3: # %if.end19 113; CHECK-NEXT: movq %rax, %rbx 114; CHECK-NEXT: xorl %eax, %eax 115; CHECK-NEXT: testb %al, %al 116; CHECK-NEXT: jne .LBB1_25 117; CHECK-NEXT: # %bb.4: # %if.end19 118; CHECK-NEXT: cmpq %r12, %rbx 119; CHECK-NEXT: jb .LBB1_25 120; CHECK-NEXT: # %bb.5: # %if.end50 121; CHECK-NEXT: movq %rbx, %rdi 122; CHECK-NEXT: movq %r15, %rdx 123; CHECK-NEXT: callq memcpy 124; CHECK-NEXT: cmpl $4, %r14d 125; CHECK-NEXT: jb .LBB1_28 126; CHECK-NEXT: # %bb.6: # %shared_preheader 127; CHECK-NEXT: movb $32, %dl 128; CHECK-NEXT: xorl %eax, %eax 129; CHECK-NEXT: # implicit-def: $rcx 130; CHECK-NEXT: testl %ebp, %ebp 131; CHECK-NEXT: je .LBB1_18 132; CHECK-NEXT: .p2align 4, 0x90 133; CHECK-NEXT: .LBB1_8: # %shared_loop_header 134; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 135; CHECK-NEXT: testq %rbx, %rbx 136; CHECK-NEXT: jne .LBB1_27 137; CHECK-NEXT: # %bb.9: # %inner_loop_body 138; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 139; CHECK-NEXT: testl %eax, %eax 140; CHECK-NEXT: jns .LBB1_8 141; CHECK-NEXT: # %bb.10: # %if.end96.i 142; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 143; CHECK-NEXT: cmpl $3, %ebp 144; CHECK-NEXT: jae .LBB1_22 145; CHECK-NEXT: # %bb.11: # %if.end287.i 146; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 147; CHECK-NEXT: xorl %esi, %esi 148; CHECK-NEXT: cmpl $1, %ebp 149; CHECK-NEXT: setne %dl 150; CHECK-NEXT: testb %al, %al 151; CHECK-NEXT: jne .LBB1_15 152; CHECK-NEXT: # %bb.12: # %if.end308.i 153; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 154; CHECK-NEXT: testb %al, %al 155; CHECK-NEXT: je .LBB1_17 156; CHECK-NEXT: # %bb.13: # %if.end335.i 157; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 158; CHECK-NEXT: xorl %edx, %edx 159; CHECK-NEXT: testb %dl, %dl 160; CHECK-NEXT: movl $0, %esi 161; CHECK-NEXT: jne .LBB1_7 162; CHECK-NEXT: # %bb.14: # %merge_other 163; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 164; CHECK-NEXT: xorl %esi, %esi 165; CHECK-NEXT: jmp .LBB1_16 166; CHECK-NEXT: .LBB1_15: # in Loop: Header=BB1_8 Depth=1 167; CHECK-NEXT: movb %dl, %sil 168; CHECK-NEXT: addl $3, %esi 169; CHECK-NEXT: .LBB1_16: # %outer_loop_latch 170; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 171; CHECK-NEXT: # implicit-def: $dl 172; CHECK-NEXT: jmp .LBB1_7 173; CHECK-NEXT: .LBB1_17: # %merge_predecessor_split 174; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 175; CHECK-NEXT: movb $32, %dl 176; CHECK-NEXT: xorl %esi, %esi 177; CHECK-NEXT: .LBB1_7: # %outer_loop_latch 178; CHECK-NEXT: # in Loop: Header=BB1_8 Depth=1 179; CHECK-NEXT: movzwl %si, %esi 180; CHECK-NEXT: decl %esi 181; CHECK-NEXT: movzwl %si, %esi 182; CHECK-NEXT: leaq 1(%rcx,%rsi), %rcx 183; CHECK-NEXT: testl %ebp, %ebp 184; CHECK-NEXT: jne .LBB1_8 185; CHECK-NEXT: .LBB1_18: # %while.cond.us1412.i 186; CHECK-NEXT: xorl %eax, %eax 187; CHECK-NEXT: testb %al, %al 188; CHECK-NEXT: movl $1, %ebx 189; CHECK-NEXT: jne .LBB1_20 190; CHECK-NEXT: # %bb.19: # %while.cond.us1412.i 191; CHECK-NEXT: decb %dl 192; CHECK-NEXT: jne .LBB1_26 193; CHECK-NEXT: .LBB1_20: # %if.end41.us1436.i 194; CHECK-NEXT: .LBB1_25: 195; CHECK-NEXT: movl $1, %ebx 196; CHECK-NEXT: jmp .LBB1_26 197; CHECK-NEXT: .LBB1_22: # %if.then99.i 198; CHECK-NEXT: xorl %ebx, %ebx 199; CHECK-NEXT: movl $.str.6, %edi 200; CHECK-NEXT: xorl %eax, %eax 201; CHECK-NEXT: callq cli_dbgmsg 202; CHECK-NEXT: .LBB1_26: # %cleanup 203; CHECK-NEXT: movl %ebx, %eax 204; CHECK-NEXT: addq $8, %rsp 205; CHECK-NEXT: popq %rbx 206; CHECK-NEXT: popq %r12 207; CHECK-NEXT: popq %r13 208; CHECK-NEXT: popq %r14 209; CHECK-NEXT: popq %r15 210; CHECK-NEXT: popq %rbp 211; CHECK-NEXT: retq 212; CHECK-NEXT: .LBB1_27: # %wunpsect.exit.thread.loopexit389 213; CHECK-NEXT: .LBB1_28: # %wunpsect.exit.thread.loopexit391 214entry: 215 %0 = load i32, i32* undef, align 4 216 %mul = shl nsw i32 %0, 2 217 br i1 undef, label %if.end19, label %cleanup 218 219if.end19: ; preds = %entry 220 %conv = zext i32 %mul to i64 221 %call = tail call i8* @cli_calloc(i64 %conv, i64 1) 222 %1 = icmp eq i32 %exesz, 0 223 %notrhs = icmp eq i32 %0, 0 224 %or.cond117.not = or i1 %1, %notrhs 225 %or.cond202 = or i1 %or.cond117.not, undef 226 %cmp35 = icmp ult i8* %call, %exe 227 %or.cond203 = or i1 %or.cond202, %cmp35 228 br i1 %or.cond203, label %cleanup, label %if.end50 229 230if.end50: ; preds = %if.end19 231 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull %call, i8* undef, i64 %conv, i1 false) 232 %cmp1.i.i = icmp ugt i32 %mul, 3 233 br i1 %cmp1.i.i, label %shared_preheader, label %wunpsect.exit.thread.loopexit391 234 235shared_preheader: ; preds = %if.end50 236 br label %outer_loop_header 237 238outer_loop_header: ; preds = %outer_loop_latch, %shared_preheader 239 %bits.1.i = phi i8 [ 32, %shared_preheader ], [ %bits.43.i, %outer_loop_latch ] 240 %dst.0.ph.i = phi i8* [ undef, %shared_preheader ], [ %scevgep679.i, %outer_loop_latch ] 241 %2 = icmp eq i32 %0, 0 242 br i1 %2, label %while.cond.us1412.i, label %shared_loop_header 243 244while.cond.us1412.i: ; preds = %outer_loop_header 245 %.pre.i = add i8 %bits.1.i, -1 246 %tobool2.us1420.i = icmp eq i8 %.pre.i, 0 247 %or.cond.us1421.i = or i1 undef, %tobool2.us1420.i 248 br i1 %or.cond.us1421.i, label %if.end41.us1436.i, label %cleanup 249 250if.end41.us1436.i: ; preds = %while.cond.us1412.i 251 unreachable 252 253shared_loop_header: ; preds = %dup_early2, %dup_early1 254 %dst.0.i = phi i8* [ undef, %inner_loop_body ], [ %dst.0.ph.i, %outer_loop_header ], [ undef, %dead_block ] 255 %cmp3.i1172.i = icmp ult i8* null, %call 256 br i1 %cmp3.i1172.i, label %wunpsect.exit.thread.loopexit389, label %inner_loop_body 257 258inner_loop_body: ; preds = %shared_loop_header 259 %3 = icmp slt i32 undef, 0 260 br i1 %3, label %if.end96.i, label %shared_loop_header 261 262dead_block: ; preds = %inner_loop_body 263 %cmp75.i = icmp ult i8* %dst.0.i, null 264 br label %shared_loop_header 265 266if.end96.i: ; preds = %inner_loop_body 267 %cmp97.i = icmp ugt i32 %0, 2 268 br i1 %cmp97.i, label %if.then99.i, label %if.end287.i 269 270if.then99.i: ; preds = %if.end96.i 271 tail call void (i8*, ...) @cli_dbgmsg(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.6, i64 0, i64 0), i32 undef) 272 br label %cleanup 273 274if.end287.i: ; preds = %if.end96.i 275 %cmp291.i = icmp ne i32 %0, 1 276 %conv294.i = select i1 %cmp291.i, i16 4, i16 3 277 br i1 undef, label %if.end308.i, label %outer_loop_latch 278 279if.end308.i: ; preds = %if.end287.i 280 br i1 undef, label %if.end335.i, label %merge_predecessor_split 281 282merge_predecessor_split: ; preds = %if.end308.i 283 %4 = bitcast i8* undef to i32* 284 br label %outer_loop_latch 285 286if.end335.i: ; preds = %if.end308.i 287 br i1 undef, label %outer_loop_latch, label %merge_other 288 289merge_other: ; preds = %if.end335.i 290 br label %outer_loop_latch 291 292outer_loop_latch: ; preds = %merge_other, %if.end335.i, %merge_predecessor_split, %if.end287.i 293 %bits.43.i = phi i8 [ undef, %if.end287.i ], [ undef, %merge_other ], [ 32, %merge_predecessor_split ], [ 0, %if.end335.i ] 294 %backsize.0.i = phi i16 [ %conv294.i, %if.end287.i ], [ 0, %merge_other ], [ 0, %merge_predecessor_split ], [ 0, %if.end335.i ] 295 %5 = add i16 %backsize.0.i, -1 296 %6 = zext i16 %5 to i64 297 %scevgep.i = getelementptr i8, i8* %dst.0.ph.i, i64 1 298 %scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 %6 299 br label %outer_loop_header 300 301wunpsect.exit.thread.loopexit389: ; preds = %shared_loop_header 302 unreachable 303 304wunpsect.exit.thread.loopexit391: ; preds = %if.end50 305 unreachable 306 307cleanup: ; preds = %if.then99.i, %while.cond.us1412.i, %if.end19, %entry 308 %retval.0 = phi i32 [ 0, %if.then99.i ], [ 1, %entry ], [ 1, %if.end19 ], [ 1, %while.cond.us1412.i ] 309 ret i32 %retval.0 310} 311 312; Function Attrs: nounwind 313declare void @cli_dbgmsg(i8*, ...) local_unnamed_addr #0 314 315; Function Attrs: nounwind 316declare i8* @cli_calloc(i64, i64) local_unnamed_addr #0 317 318; Function Attrs: argmemonly nounwind 319declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i1) #1 320attributes #0 = { nounwind } 321attributes #1 = { argmemonly nounwind } 322