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1; RUN: opt < %s -passes=gvn-sink,simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=true -simplifycfg-sink-common=false -S | FileCheck %s2 3define zeroext i1 @test1(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {4entry:5 br i1 %flag, label %if.then, label %if.else6 7; CHECK-LABEL: test18; CHECK: add9; CHECK: select10; CHECK: icmp11; CHECK-NOT: br12if.then:13 %cmp = icmp uge i32 %blksA, %nblks14 %frombool1 = zext i1 %cmp to i815 br label %if.end16 17if.else:18 %add = add i32 %nblks, %blksB19 %cmp2 = icmp ule i32 %add, %blksA20 %frombool3 = zext i1 %cmp2 to i821 br label %if.end22 23if.end:24 %obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.else ]25 %tobool4 = icmp ne i8 %obeys.0, 026 ret i1 %tobool427}28 29define zeroext i1 @test2(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {30entry:31 br i1 %flag, label %if.then, label %if.else32 33; CHECK-LABEL: test234; CHECK: add35; CHECK: select36; CHECK: icmp37; CHECK-NOT: br38if.then:39 %cmp = icmp uge i32 %blksA, %nblks40 %frombool1 = zext i1 %cmp to i841 br label %if.end42 43if.else:44 %add = add i32 %nblks, %blksB45 %cmp2 = icmp uge i32 %blksA, %add46 %frombool3 = zext i1 %cmp2 to i847 br label %if.end48 49if.end:50 %obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.else ]51 %tobool4 = icmp ne i8 %obeys.0, 052 ret i1 %tobool453}54 55declare i32 @foo(i32, i32) nounwind readnone56 57; FIXME: The test failes when the original order of the58; candidates with the same cost is preserved.59;60;define i32 @test3(i1 zeroext %flag, i32 %x, i32 %y) {61;entry:62; br i1 %flag, label %if.then, label %if.else63;64;if.then:65; %x0 = call i32 @foo(i32 %x, i32 0) nounwind readnone66; %y0 = call i32 @foo(i32 %x, i32 1) nounwind readnone67; br label %if.end68;69;if.else:70; %x1 = call i32 @foo(i32 %y, i32 0) nounwind readnone71; %y1 = call i32 @foo(i32 %y, i32 1) nounwind readnone72; br label %if.end73;74;if.end:75; %xx = phi i32 [ %x0, %if.then ], [ %x1, %if.else ]76; %yy = phi i32 [ %y0, %if.then ], [ %y1, %if.else ]77; %ret = add i32 %xx, %yy78; ret i32 %ret79;}80;81; -CHECK-LABEL: test382; -CHECK: select83; -CHECK: call84; -CHECK: call85; -CHECK: add86; -CHECK-NOT: br87 88define i32 @test4(i1 zeroext %flag, i32 %x, ptr %y) {89entry:90 br i1 %flag, label %if.then, label %if.else91 92if.then:93 %a = add i32 %x, 594 store i32 %a, ptr %y95 br label %if.end96 97if.else:98 %b = add i32 %x, 799 store i32 %b, ptr %y100 br label %if.end101 102if.end:103 ret i32 1104}105 106; CHECK-LABEL: test4107; CHECK: select108; CHECK: store109; CHECK-NOT: store110 111define i32 @test5(i1 zeroext %flag, i32 %x, ptr %y) {112entry:113 br i1 %flag, label %if.then, label %if.else114 115if.then:116 %a = add i32 %x, 5117 store volatile i32 %a, ptr %y118 br label %if.end119 120if.else:121 %b = add i32 %x, 7122 store i32 %b, ptr %y123 br label %if.end124 125if.end:126 ret i32 1127}128 129; CHECK-LABEL: test5130; CHECK: store volatile131; CHECK: store132 133define i32 @test6(i1 zeroext %flag, i32 %x, ptr %y) {134entry:135 br i1 %flag, label %if.then, label %if.else136 137if.then:138 %a = add i32 %x, 5139 store volatile i32 %a, ptr %y140 br label %if.end141 142if.else:143 %b = add i32 %x, 7144 store volatile i32 %b, ptr %y145 br label %if.end146 147if.end:148 ret i32 1149}150 151; CHECK-LABEL: test6152; CHECK: select153; CHECK: store volatile154; CHECK-NOT: store155 156define i32 @test7(i1 zeroext %flag, i32 %x, ptr %y) {157entry:158 br i1 %flag, label %if.then, label %if.else159 160if.then:161 %z = load volatile i32, ptr %y162 %a = add i32 %z, 5163 store volatile i32 %a, ptr %y164 br label %if.end165 166if.else:167 %w = load volatile i32, ptr %y168 %b = add i32 %w, 7169 store volatile i32 %b, ptr %y170 br label %if.end171 172if.end:173 ret i32 1174}175 176; CHECK-LABEL: test7177; CHECK-DAG: select178; CHECK-DAG: load volatile179; CHECK: store volatile180; CHECK-NOT: load181; CHECK-NOT: store182 183; The extra store in %if.then means %z and %w are not equivalent.184define i32 @test9(i1 zeroext %flag, i32 %x, ptr %y, ptr %p) {185entry:186 br i1 %flag, label %if.then, label %if.else187 188if.then:189 store i32 7, ptr %p190 %z = load volatile i32, ptr %y191 store i32 6, ptr %p192 %a = add i32 %z, 5193 store volatile i32 %a, ptr %y194 br label %if.end195 196if.else:197 %w = load volatile i32, ptr %y198 %b = add i32 %w, 7199 store volatile i32 %b, ptr %y200 br label %if.end201 202if.end:203 ret i32 1204}205 206; CHECK-LABEL: test9207; CHECK: add208; CHECK: add209 210%struct.anon = type { i32, i32, i32 }211 212; The GEP indexes a struct type so cannot have a variable last index.213define i32 @test10(i1 zeroext %flag, i32 %x, ptr %y, ptr %s) {214entry:215 br i1 %flag, label %if.then, label %if.else216 217if.then:218 %dummy = add i32 %x, 5219 %gepa = getelementptr inbounds %struct.anon, ptr %s, i32 0, i32 1220 store volatile i32 %x, ptr %gepa221 br label %if.end222 223if.else:224 %dummy1 = add i32 %x, 6225 %gepb = getelementptr inbounds %struct.anon, ptr %s, i32 0, i32 2226 store volatile i32 %x, ptr %gepb227 br label %if.end228 229if.end:230 ret i32 1231}232 233; CHECK-LABEL: test10234; CHECK: getelementptr235; CHECK: store volatile236; CHECK: getelementptr237; CHECK: store volatile238 239; The shufflevector's mask operand cannot be merged in a PHI.240define i32 @test11(i1 zeroext %flag, i32 %w, <2 x i32> %x, <2 x i32> %y) {241entry:242 br i1 %flag, label %if.then, label %if.else243 244if.then:245 %dummy = add i32 %w, 5246 %sv1 = shufflevector <2 x i32> %x, <2 x i32> %y, <2 x i32> <i32 0, i32 1>247 br label %if.end248 249if.else:250 %dummy1 = add i32 %w, 6251 %sv2 = shufflevector <2 x i32> %x, <2 x i32> %y, <2 x i32> <i32 1, i32 0>252 br label %if.end253 254if.end:255 %p = phi <2 x i32> [ %sv1, %if.then ], [ %sv2, %if.else ]256 ret i32 1257}258 259; CHECK-LABEL: test11260; CHECK: shufflevector261; CHECK: shufflevector262 263; We can't common an intrinsic!264define i32 @test12(i1 zeroext %flag, i32 %w, i32 %x, i32 %y) {265entry:266 br i1 %flag, label %if.then, label %if.else267 268if.then:269 %dummy = add i32 %w, 5270 %sv1 = call i32 @llvm.ctlz.i32(i32 %x)271 br label %if.end272 273if.else:274 %dummy1 = add i32 %w, 6275 %sv2 = call i32 @llvm.cttz.i32(i32 %x)276 br label %if.end277 278if.end:279 %p = phi i32 [ %sv1, %if.then ], [ %sv2, %if.else ]280 ret i32 1281}282 283declare i32 @llvm.ctlz.i32(i32 %x) readnone284declare i32 @llvm.cttz.i32(i32 %x) readnone285 286; CHECK-LABEL: test12287; CHECK: call i32 @llvm.ctlz288; CHECK: call i32 @llvm.cttz289 290; The TBAA metadata should be properly combined.291define i32 @test13(i1 zeroext %flag, i32 %x, ptr %y) {292entry:293 br i1 %flag, label %if.then, label %if.else294 295if.then:296 %z = load volatile i32, ptr %y297 %a = add i32 %z, 5298 store volatile i32 %a, ptr %y, !tbaa !3299 br label %if.end300 301if.else:302 %w = load volatile i32, ptr %y303 %b = add i32 %w, 7304 store volatile i32 %b, ptr %y, !tbaa !4305 br label %if.end306 307if.end:308 ret i32 1309}310 311!0 = !{ !"an example type tree" }312!1 = !{ !"int", !0 }313!2 = !{ !"float", !0 }314!3 = !{ !"const float", !2, i64 0 }315!4 = !{ !"special float", !2, i64 1 }316 317; CHECK-LABEL: test13318; CHECK-DAG: select319; CHECK-DAG: load volatile320; CHECK: store volatile {{.*}}, !tbaa !0321; CHECK-NOT: load322; CHECK-NOT: store323 324; The call should be commoned.325define i32 @test13a(i1 zeroext %flag, i32 %w, i32 %x, i32 %y) {326entry:327 br i1 %flag, label %if.then, label %if.else328 329if.then:330 %sv1 = call i32 @bar(i32 %x)331 br label %if.end332 333if.else:334 %sv2 = call i32 @bar(i32 %y)335 br label %if.end336 337if.end:338 %p = phi i32 [ %sv1, %if.then ], [ %sv2, %if.else ]339 ret i32 1340}341declare i32 @bar(i32)342 343; CHECK-LABEL: test13a344; CHECK: %[[x:.*]] = select i1 %flag345; CHECK: call i32 @bar(i32 %[[x]])346 347; The load should be commoned.348define i32 @test14(i1 zeroext %flag, i32 %w, i32 %x, i32 %y, ptr %s) {349entry:350 br i1 %flag, label %if.then, label %if.else351 352if.then:353 %dummy = add i32 %x, 1354 %gepa = getelementptr inbounds %struct.anon, ptr %s, i32 0, i32 1355 %sv1 = load i32, ptr %gepa356 %cmp1 = icmp eq i32 %sv1, 56357 br label %if.end358 359if.else:360 %dummy2 = add i32 %x, 4361 %gepb = getelementptr inbounds %struct.anon, ptr %s, i32 0, i32 1362 %sv2 = load i32, ptr %gepb363 %cmp2 = icmp eq i32 %sv2, 57364 br label %if.end365 366if.end:367 %p = phi i1 [ %cmp1, %if.then ], [ %cmp2, %if.else ]368 ret i32 1369}370 371; CHECK-LABEL: test14372; CHECK: getelementptr373; CHECK: load374; CHECK-NOT: load375 376; The load should be commoned.377define i32 @test15(i1 zeroext %flag, i32 %w, i32 %x, i32 %y, ptr %s) {378entry:379 br i1 %flag, label %if.then, label %if.else380 381if.then:382 %dummy = add i32 %x, 1383 %gepa = getelementptr inbounds %struct.anon, ptr %s, i32 0, i32 0384 %sv1 = load i32, ptr %gepa385 %ext1 = zext i32 %sv1 to i64386 %cmp1 = icmp eq i64 %ext1, 56387 br label %if.end388 389if.else:390 %dummy2 = add i32 %x, 4391 %gepb = getelementptr inbounds %struct.anon, ptr %s, i32 0, i32 1392 %sv2 = load i32, ptr %gepb393 %ext2 = zext i32 %sv2 to i64394 %cmp2 = icmp eq i64 %ext2, 56395 br label %if.end396 397if.end:398 %p = phi i1 [ %cmp1, %if.then ], [ %cmp2, %if.else ]399 ret i32 1400}401 402; CHECK-LABEL: test15403; CHECK: getelementptr404; CHECK: load405; CHECK-NOT: load406 407define zeroext i1 @test_crash(i1 zeroext %flag, ptr %i4, ptr %m, ptr %n) {408entry:409 br i1 %flag, label %if.then, label %if.else410 411if.then:412 %tmp1 = load i32, ptr %i4413 %tmp2 = add i32 %tmp1, -1414 store i32 %tmp2, ptr %i4415 br label %if.end416 417if.else:418 %tmp3 = load i32, ptr %m419 %tmp4 = load i32, ptr %n420 %tmp5 = add i32 %tmp3, %tmp4421 store i32 %tmp5, ptr %i4422 br label %if.end423 424if.end:425 ret i1 true426}427 428; CHECK-LABEL: test_crash429; No checks for test_crash - just ensure it doesn't crash!430 431define zeroext i1 @test16(i1 zeroext %flag, i1 zeroext %flag2, i32 %blksA, i32 %blksB, i32 %nblks) {432 433entry:434 br i1 %flag, label %if.then, label %if.else435 436if.then:437 %cmp = icmp uge i32 %blksA, %nblks438 %frombool1 = zext i1 %cmp to i8439 br label %if.end440 441if.else:442 br i1 %flag2, label %if.then2, label %if.end443 444if.then2:445 %add = add i32 %nblks, %blksB446 %cmp2 = icmp ule i32 %add, %blksA447 %frombool3 = zext i1 %cmp2 to i8448 br label %if.end449 450if.end:451 %obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.then2 ], [ 0, %if.else ]452 %tobool4 = icmp ne i8 %obeys.0, 0453 ret i1 %tobool4454}455 456; CHECK-LABEL: test16457; CHECK: zext458; CHECK: zext459 460define zeroext i1 @test16a(i1 zeroext %flag, i1 zeroext %flag2, i32 %blksA, i32 %blksB, i32 %nblks, ptr %p) {461 462entry:463 br i1 %flag, label %if.then, label %if.else464 465if.then:466 %cmp = icmp uge i32 %blksA, %nblks467 %frombool1 = zext i1 %cmp to i8468 %b1 = sext i8 %frombool1 to i32469 %b2 = trunc i32 %b1 to i8470 store i8 %b2, ptr %p471 br label %if.end472 473if.else:474 br i1 %flag2, label %if.then2, label %if.end475 476if.then2:477 %add = add i32 %nblks, %blksB478 %cmp2 = icmp ule i32 %add, %blksA479 %frombool3 = zext i1 %cmp2 to i8480 %a1 = sext i8 %frombool3 to i32481 %a2 = trunc i32 %a1 to i8482 store i8 %a2, ptr %p483 br label %if.end484 485if.end:486 ret i1 true487}488 489; CHECK-LABEL: test16a490; CHECK: zext491; CHECK-NOT: zext492 493define zeroext i1 @test17(i32 %flag, i32 %blksA, i32 %blksB, i32 %nblks) {494entry:495 switch i32 %flag, label %if.end [496 i32 0, label %if.then497 i32 1, label %if.then2498 ]499 500if.then:501 %cmp = icmp uge i32 %blksA, %nblks502 %frombool1 = call i8 @i1toi8(i1 %cmp)503 %a1 = sext i8 %frombool1 to i32504 %a2 = trunc i32 %a1 to i8505 br label %if.end506 507if.then2:508 %add = add i32 %nblks, %blksB509 %cmp2 = icmp ule i32 %add, %blksA510 %frombool3 = call i8 @i1toi8(i1 %cmp2)511 %b1 = sext i8 %frombool3 to i32512 %b2 = trunc i32 %b1 to i8513 br label %if.end514 515if.end:516 %obeys.0 = phi i8 [ %a2, %if.then ], [ %b2, %if.then2 ], [ 0, %entry ]517 %tobool4 = icmp ne i8 %obeys.0, 0518 ret i1 %tobool4519}520declare i8 @i1toi8(i1)521 522; FIXME: DISABLED - we don't consider this profitable. We should523; - Consider argument setup/return mov'ing for calls, like InlineCost does.524; - Consider the removal of the %obeys.0 PHI (zero PHI movement overall)525 526; DISABLED-CHECK-LABEL: test17527; DISABLED-CHECK: if.then:528; DISABLED-CHECK-NEXT: icmp uge529; DISABLED-CHECK-NEXT: br label %[[x:.*]]530 531; DISABLED-CHECK: if.then2:532; DISABLED-CHECK-NEXT: add533; DISABLED-CHECK-NEXT: icmp ule534; DISABLED-CHECK-NEXT: br label %[[x]]535 536; DISABLED-CHECK: [[x]]:537; DISABLED-CHECK-NEXT: %[[y:.*]] = phi i1 [ %cmp538; DISABLED-CHECK-NEXT: %[[z:.*]] = call i8 @i1toi8(i1 %[[y]])539; DISABLED-CHECK-NEXT: br label %if.end540 541; DISABLED-CHECK: if.end:542; DISABLED-CHECK-NEXT: phi i8543; DISABLED-CHECK-DAG: [ %[[z]], %[[x]] ]544; DISABLED-CHECK-DAG: [ 0, %entry ]545 546define zeroext i1 @test18(i32 %flag, i32 %blksA, i32 %blksB, i32 %nblks) {547entry:548 switch i32 %flag, label %if.then3 [549 i32 0, label %if.then550 i32 1, label %if.then2551 ]552 553if.then:554 %cmp = icmp uge i32 %blksA, %nblks555 %frombool1 = zext i1 %cmp to i8556 br label %if.end557 558if.then2:559 %add = add i32 %nblks, %blksB560 %cmp2 = icmp ule i32 %add, %blksA561 %frombool3 = zext i1 %cmp2 to i8562 br label %if.end563 564if.then3:565 %add2 = add i32 %nblks, %blksA566 %cmp3 = icmp ule i32 %add2, %blksA567 %frombool4 = zext i1 %cmp3 to i8568 br label %if.end569 570if.end:571 %obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.then2 ], [ %frombool4, %if.then3 ]572 %tobool4 = icmp ne i8 %obeys.0, 0573 ret i1 %tobool4574}575 576; CHECK-LABEL: test18577; CHECK: if.end:578; CHECK-NEXT: %[[x:.*]] = phi i1579; CHECK-DAG: [ %cmp, %if.then ]580; CHECK-DAG: [ %cmp2, %if.then2 ]581; CHECK-DAG: [ %cmp3, %if.then3 ]582; CHECK-NEXT: zext i1 %[[x]] to i8583 584; The phi is confusing - both add instructions are used by it, but585; not on their respective unconditional arcs. It should not be586; optimized.587define void @test_pr30292(i1 %cond, i1 %cond2, i32 %a, i32 %b) {588entry:589 %add1 = add i32 %a, 1590 br label %succ591 592one:593 br i1 %cond, label %two, label %succ594 595two:596 call void @g()597 %add2 = add i32 %a, 1598 br label %succ599 600succ:601 %p = phi i32 [ 0, %entry ], [ %add1, %one ], [ %add2, %two ]602 br label %one603}604declare void @g()605 606; CHECK-LABEL: test_pr30292607; CHECK: phi i32 [ 0, %entry ], [ %add1, %succ ], [ %add2, %two ]608 609define zeroext i1 @test_pr30244(i1 zeroext %flag, i1 zeroext %flag2, i32 %blksA, i32 %blksB, i32 %nblks) {610 611entry:612 %p = alloca i8613 br i1 %flag, label %if.then, label %if.else614 615if.then:616 %cmp = icmp uge i32 %blksA, %nblks617 %frombool1 = zext i1 %cmp to i8618 store i8 %frombool1, ptr %p619 br label %if.end620 621if.else:622 br i1 %flag2, label %if.then2, label %if.end623 624if.then2:625 %add = add i32 %nblks, %blksB626 %cmp2 = icmp ule i32 %add, %blksA627 %frombool3 = zext i1 %cmp2 to i8628 store i8 %frombool3, ptr %p629 br label %if.end630 631if.end:632 ret i1 true633}634 635; CHECK-LABEL: @test_pr30244636; CHECK: store637; CHECK-NOT: store638 639define i32 @test_pr30373a(i1 zeroext %flag, i32 %x, i32 %y) {640entry:641 br i1 %flag, label %if.then, label %if.else642 643if.then:644 %x0 = call i32 @foo(i32 %x, i32 0) nounwind readnone645 %y0 = call i32 @foo(i32 %x, i32 1) nounwind readnone646 %z0 = lshr i32 %y0, 8647 br label %if.end648 649if.else:650 %x1 = call i32 @foo(i32 %y, i32 0) nounwind readnone651 %y1 = call i32 @foo(i32 %y, i32 1) nounwind readnone652 %z1 = lshr exact i32 %y1, 8653 br label %if.end654 655if.end:656 %xx = phi i32 [ %x0, %if.then ], [ %x1, %if.else ]657 %yy = phi i32 [ %z0, %if.then ], [ %z1, %if.else ]658 %ret = add i32 %xx, %yy659 ret i32 %ret660}661 662; CHECK-LABEL: test_pr30373a663; CHECK: lshr664; CHECK-NOT: exact665; CHECK: }666 667define i32 @test_pr30373b(i1 zeroext %flag, i32 %x, i32 %y) {668entry:669 br i1 %flag, label %if.then, label %if.else670 671if.then:672 %x0 = call i32 @foo(i32 %x, i32 0) nounwind readnone673 %y0 = call i32 @foo(i32 %x, i32 1) nounwind readnone674 %z0 = lshr exact i32 %y0, 8675 br label %if.end676 677if.else:678 %x1 = call i32 @foo(i32 %y, i32 0) nounwind readnone679 %y1 = call i32 @foo(i32 %y, i32 1) nounwind readnone680 %z1 = lshr i32 %y1, 8681 br label %if.end682 683if.end:684 %xx = phi i32 [ %x0, %if.then ], [ %x1, %if.else ]685 %yy = phi i32 [ %z0, %if.then ], [ %z1, %if.else ]686 %ret = add i32 %xx, %yy687 ret i32 %ret688}689 690; CHECK-LABEL: test_pr30373b691; CHECK: lshr692; CHECK-NOT: exact693; CHECK: }694 695 696; CHECK-LABEL: @common_bitcast(697; CHECK: %. = select i1 %flag, float 2.000000e+00, float 1.000000e+00698; CHECK: %[[a1:.*]] = bitcast ptr %x to ptr699; CHECK: store float %., ptr %[[a1]]700define i32 @common_bitcast(i1 zeroext %flag, ptr %x) {701entry:702 br i1 %flag, label %if.then, label %if.else703 704if.then:705 %a = bitcast ptr %x to ptr706 store float 2.0, ptr %a707 br label %if.end708 709if.else:710 %b = bitcast ptr %x to ptr711 store float 1.0, ptr %b712 br label %if.end713 714if.end:715 ret i32 1716}717 718; CHECK-LABEL: @common_addrspacecast(719; CHECK: %. = select i1 %flag, i32 9, i32 10720; CHECK: %[[a2:.*]] = addrspacecast ptr %x to ptr addrspace(1)721; CHECK: store i32 %., ptr addrspace(1) %[[a2]]722define i32 @common_addrspacecast(i1 zeroext %flag, ptr %x) {723entry:724 br i1 %flag, label %if.then, label %if.else725 726if.then:727 %a = addrspacecast ptr %x to ptr addrspace(1)728 store i32 9, ptr addrspace(1) %a729 br label %if.end730 731if.else:732 %b = addrspacecast ptr %x to ptr addrspace(1)733 store i32 10, ptr addrspace(1) %b734 br label %if.end735 736if.end:737 ret i32 1738}739 740; Don't merge different address spaces741; CHECK-LABEL: @no_common_addrspacecast(742; CHECK: addrspacecast ptr %x to ptr addrspace(1)743; CHECK: addrspacecast ptr %x to ptr addrspace(3)744define i32 @no_common_addrspacecast(i1 zeroext %flag, ptr %x) {745entry:746 br i1 %flag, label %if.then, label %if.else747 748if.then:749 %a = addrspacecast ptr %x to ptr addrspace(1)750 store i32 9, ptr addrspace(1) %a751 br label %if.end752 753if.else:754 %b = addrspacecast ptr %x to ptr addrspace(3)755 store i32 10, ptr addrspace(3) %b756 br label %if.end757 758if.end:759 ret i32 1760}761 762; CHECK-LABEL: test_pr36954763; CHECK-NOT: xor764; PR36954 reproducer containing self referencing instruction shouldn't crash GVNSink pass.765define void @test_pr36954(i1 %arg) {766bb1:767 %i2 = trunc i32 undef to i8768 br label %bb2769 770bb2:771 br i1 %arg, label %bb2, label %exit772 773bb4.critedge:774 %i6 = sub i8 %i2, undef775 %i7 = zext i8 %i6 to i32776 %i8 = xor i32 %i8, %i7777 br i1 false, label %exit, label %bb4.critedge778 779exit:780 ret void781}782 783; CHECK: !0 = !{!1, !1, i64 0}784; CHECK: !1 = !{!"float", !2}785; CHECK: !2 = !{!"an example type tree"}786