; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -S -loop-unroll -verify-loop-info | FileCheck %s ; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop-unroll,verify<loops>' | FileCheck %s ; ; Unit tests for LoopInfo::markAsRemoved. declare i1 @check() nounwind ; Ensure that tail->inner is removed and rely on verify-loopinfo to ; check soundness. define void @skiplevelexit() nounwind { ; CHECK-LABEL: @skiplevelexit( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[OUTER:%.*]] ; CHECK: outer: ; CHECK-NEXT: br label [[INNER:%.*]] ; CHECK: inner: ; CHECK-NEXT: [[TMP0:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 true, label [[OUTER_BACKEDGE:%.*]], label [[TAIL:%.*]] ; CHECK: tail: ; CHECK-NEXT: ret void ; CHECK: outer.backedge: ; CHECK-NEXT: br label [[OUTER]] ; entry: br label %outer outer: br label %inner inner: %iv = phi i32 [ 0, %outer ], [ %inc, %tail ] %inc = add i32 %iv, 1 call zeroext i1 @check() br i1 true, label %outer.backedge, label %tail tail: br i1 false, label %inner, label %exit outer.backedge: br label %outer exit: ret void } ; Remove the middle loop of a triply nested loop tree. ; Ensure that only the middle loop is removed and rely on verify-loopinfo to ; check soundness. define void @unloopNested() { ; CHECK-LABEL: @unloopNested( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[WHILE_COND_OUTER:%.*]] ; CHECK: while.cond.outer: ; CHECK-NEXT: br label [[WHILE_COND:%.*]] ; CHECK: while.cond: ; CHECK-NEXT: [[CMP:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP]], label [[WHILE_BODY:%.*]], label [[WHILE_END:%.*]] ; CHECK: while.body: ; CHECK-NEXT: [[CMP3:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP3]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br label [[RETURN:%.*]] ; CHECK: if.end: ; CHECK-NEXT: [[CMP_I48:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP_I48]], label [[IF_THEN_I:%.*]], label [[IF_ELSE20_I:%.*]] ; CHECK: if.then.i: ; CHECK-NEXT: [[CMP8_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP8_I]], label [[MERGE:%.*]], label [[IF_ELSE_I:%.*]] ; CHECK: if.else.i: ; CHECK-NEXT: br label [[MERGE]] ; CHECK: if.else20.i: ; CHECK-NEXT: [[CMP25_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP25_I]], label [[MERGE]], label [[IF_ELSE28_I:%.*]] ; CHECK: if.else28.i: ; CHECK-NEXT: br label [[MERGE]] ; CHECK: merge: ; CHECK-NEXT: br label [[WHILE_COND2_I:%.*]] ; CHECK: while.cond2.i: ; CHECK-NEXT: [[CMP_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP_I]], label [[WHILE_COND2_BACKEDGE_I:%.*]], label [[WHILE_END_I:%.*]] ; CHECK: while.cond2.backedge.i: ; CHECK-NEXT: br label [[WHILE_COND2_I]] ; CHECK: while.end.i: ; CHECK-NEXT: [[CMP1114_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP1114_I]], label [[WHILE_BODY12_LR_PH_I:%.*]], label [[WHILE_END14_I:%.*]] ; CHECK: while.body12.lr.ph.i: ; CHECK-NEXT: br label [[WHILE_END14_I]] ; CHECK: while.end14.i: ; CHECK-NEXT: [[CALL15_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CALL15_I]], label [[IF_END_I:%.*]], label [[EXIT:%.*]] ; CHECK: if.end.i: ; CHECK-NEXT: br label [[WHILE_COND2_BACKEDGE_I]] ; CHECK: exit: ; CHECK-NEXT: br label [[WHILE_COND_OUTER]] ; CHECK: while.end: ; CHECK-NEXT: br label [[RETURN]] ; CHECK: return: ; CHECK-NEXT: ret void ; entry: br label %while.cond.outer while.cond.outer: br label %while.cond while.cond: %cmp = call zeroext i1 @check() br i1 %cmp, label %while.body, label %while.end while.body: %cmp3 = call zeroext i1 @check() br i1 %cmp3, label %if.then, label %if.end if.then: br label %return if.end: %cmp.i48 = call zeroext i1 @check() br i1 %cmp.i48, label %if.then.i, label %if.else20.i if.then.i: %cmp8.i = call zeroext i1 @check() br i1 %cmp8.i, label %merge, label %if.else.i if.else.i: br label %merge if.else20.i: %cmp25.i = call zeroext i1 @check() br i1 %cmp25.i, label %merge, label %if.else28.i if.else28.i: br label %merge merge: br label %while.cond2.i while.cond2.i: %cmp.i = call zeroext i1 @check() br i1 %cmp.i, label %while.cond2.backedge.i, label %while.end.i while.cond2.backedge.i: br label %while.cond2.i while.end.i: %cmp1114.i = call zeroext i1 @check() br i1 %cmp1114.i, label %while.body12.lr.ph.i, label %while.end14.i while.body12.lr.ph.i: br label %while.end14.i while.end14.i: %call15.i = call zeroext i1 @check() br i1 %call15.i, label %if.end.i, label %exit if.end.i: br label %while.cond2.backedge.i exit: br i1 false, label %while.cond, label %if.else if.else: br label %while.cond.outer while.end: br label %return return: ret void } ; Remove the middle loop of a deeply nested loop tree. ; Ensure that only the middle loop is removed and rely on verify-loopinfo to ; check soundness. ; ; This test must be disabled until trip count computation can be optimized... ; rdar:14038809 [SCEV]: Optimize trip count computation for multi-exit loops. define void @unloopDeepNested() nounwind { ; CHECK-LABEL: @unloopDeepNested( ; CHECK-NEXT: for.cond8.preheader.i: ; CHECK-NEXT: [[CMP113_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP113_I]], label [[MAKE_DATA_EXIT:%.*]], label [[FOR_BODY13_LR_PH_I:%.*]] ; CHECK: for.body13.lr.ph.i: ; CHECK-NEXT: br label [[MAKE_DATA_EXIT]] ; CHECK: make_data.exit: ; CHECK-NEXT: br label [[WHILE_COND_OUTER_OUTER:%.*]] ; CHECK: while.cond.outer.outer: ; CHECK-NEXT: br label [[WHILE_COND_OUTER:%.*]] ; CHECK: while.cond.outer: ; CHECK-NEXT: br label [[WHILE_COND:%.*]] ; CHECK: while.cond: ; CHECK-NEXT: br label [[WHILE_COND_OUTER_I:%.*]] ; CHECK: while.cond.outer.i: ; CHECK-NEXT: [[TMP192_PH_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[TMP192_PH_I]], label [[WHILE_COND_OUTER_SPLIT_US_I:%.*]], label [[WHILE_BODY_LOOPEXIT:%.*]] ; CHECK: while.cond.outer.split.us.i: ; CHECK-NEXT: br label [[WHILE_COND_US_I:%.*]] ; CHECK: while.cond.us.i: ; CHECK-NEXT: [[CMP_US_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP_US_I]], label [[NEXT_DATA_EXIT:%.*]], label [[WHILE_BODY_US_I:%.*]] ; CHECK: while.body.us.i: ; CHECK-NEXT: [[CMP7_US_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP7_US_I]], label [[IF_THEN_US_I:%.*]], label [[IF_ELSE_I:%.*]] ; CHECK: if.then.us.i: ; CHECK-NEXT: br label [[WHILE_COND_US_I]] ; CHECK: if.else.i: ; CHECK-NEXT: br label [[WHILE_COND_OUTER_I]] ; CHECK: next_data.exit: ; CHECK-NEXT: [[TMP192_PH_I_LCSSA28:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[TMP192_PH_I_LCSSA28]], label [[WHILE_END:%.*]], label [[WHILE_BODY:%.*]] ; CHECK: while.body.loopexit: ; CHECK-NEXT: br label [[WHILE_BODY]] ; CHECK: while.body: ; CHECK-NEXT: br label [[WHILE_COND_I:%.*]] ; CHECK: while.cond.i: ; CHECK-NEXT: [[CMP_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP_I]], label [[VALID_DATA_EXIT:%.*]], label [[WHILE_BODY_I:%.*]] ; CHECK: while.body.i: ; CHECK-NEXT: [[CMP7_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP7_I]], label [[VALID_DATA_EXIT]], label [[IF_END_I:%.*]] ; CHECK: if.end.i: ; CHECK-NEXT: br label [[WHILE_COND_I]] ; CHECK: valid_data.exit: ; CHECK-NEXT: [[CMP:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP]], label [[IF_THEN12:%.*]], label [[IF_END:%.*]] ; CHECK: if.then12: ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: [[TOBOOL3_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[TOBOOL3_I]], label [[COPY_DATA_EXIT:%.*]], label [[WHILE_BODY_LR_PH_I:%.*]] ; CHECK: while.body.lr.ph.i: ; CHECK-NEXT: br label [[COPY_DATA_EXIT]] ; CHECK: copy_data.exit: ; CHECK-NEXT: [[CMP38:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP38]], label [[IF_THEN39:%.*]], label [[WHILE_COND_OUTER]] ; CHECK: if.then39: ; CHECK-NEXT: [[CMP5_I:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP5_I]], label [[WHILE_COND_OUTER_OUTER_BACKEDGE:%.*]], label [[FOR_COND8_PREHEADER_I8_THREAD:%.*]] ; CHECK: for.cond8.preheader.i8.thread: ; CHECK-NEXT: br label [[WHILE_COND_OUTER_OUTER_BACKEDGE]] ; CHECK: while.cond.outer.outer.backedge: ; CHECK-NEXT: br label [[WHILE_COND_OUTER_OUTER]] ; CHECK: while.end: ; CHECK-NEXT: ret void ; for.cond8.preheader.i: %cmp113.i = call zeroext i1 @check() br i1 %cmp113.i, label %make_data.exit, label %for.body13.lr.ph.i for.body13.lr.ph.i: br label %make_data.exit make_data.exit: br label %while.cond.outer.outer while.cond.outer.outer: br label %while.cond.outer while.cond.outer: br label %while.cond while.cond: br label %while.cond.outer.i while.cond.outer.i: %tmp192.ph.i = call zeroext i1 @check() br i1 %tmp192.ph.i, label %while.cond.outer.split.us.i, label %while.body.loopexit while.cond.outer.split.us.i: br label %while.cond.us.i while.cond.us.i: %cmp.us.i = call zeroext i1 @check() br i1 %cmp.us.i, label %next_data.exit, label %while.body.us.i while.body.us.i: %cmp7.us.i = call zeroext i1 @check() br i1 %cmp7.us.i, label %if.then.us.i, label %if.else.i if.then.us.i: br label %while.cond.us.i if.else.i: br label %while.cond.outer.i next_data.exit: %tmp192.ph.i.lcssa28 = call zeroext i1 @check() br i1 %tmp192.ph.i.lcssa28, label %while.end, label %while.body while.body.loopexit: br label %while.body while.body: br label %while.cond.i while.cond.i: %cmp.i = call zeroext i1 @check() br i1 %cmp.i, label %valid_data.exit, label %while.body.i while.body.i: %cmp7.i = call zeroext i1 @check() br i1 %cmp7.i, label %valid_data.exit, label %if.end.i if.end.i: br label %while.cond.i valid_data.exit: br i1 true, label %if.then, label %while.cond if.then: %cmp = call zeroext i1 @check() br i1 %cmp, label %if.then12, label %if.end if.then12: br label %if.end if.end: %tobool3.i = call zeroext i1 @check() br i1 %tobool3.i, label %copy_data.exit, label %while.body.lr.ph.i while.body.lr.ph.i: br label %copy_data.exit copy_data.exit: %cmp38 = call zeroext i1 @check() br i1 %cmp38, label %if.then39, label %while.cond.outer if.then39: %cmp5.i = call zeroext i1 @check() br i1 %cmp5.i, label %while.cond.outer.outer.backedge, label %for.cond8.preheader.i8.thread for.cond8.preheader.i8.thread: br label %while.cond.outer.outer.backedge while.cond.outer.outer.backedge: br label %while.cond.outer.outer while.end: ret void } ; Remove a nested loop with irreducible control flow. ; Ensure that only the middle loop is removed and rely on verify-loopinfo to ; check soundness. define void @unloopIrreducible() nounwind { ; CHECK-LABEL: @unloopIrreducible( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[CMP2113:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP2113]], label [[FOR_BODY22_LR_PH:%.*]], label [[FOR_INC163:%.*]] ; CHECK: for.body22.lr.ph: ; CHECK-NEXT: br label [[FOR_BODY22:%.*]] ; CHECK: for.body22: ; CHECK-NEXT: br label [[FOR_BODY33:%.*]] ; CHECK: for.body33: ; CHECK-NEXT: br label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: [[CMP424:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP424]], label [[FOR_BODY43_LR_PH:%.*]], label [[FOR_END93:%.*]] ; CHECK: for.body43.lr.ph: ; CHECK-NEXT: br label [[FOR_END93]] ; CHECK: for.end93: ; CHECK-NEXT: [[CMP96:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP96]], label [[IF_THEN97:%.*]], label [[FOR_COND103:%.*]] ; CHECK: if.then97: ; CHECK-NEXT: br label [[FOR_COND103T:%.*]] ; CHECK: for.cond103t: ; CHECK-NEXT: br label [[FOR_COND103]] ; CHECK: for.cond103: ; CHECK-NEXT: [[CMP105:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP105]], label [[FOR_BODY106:%.*]], label [[FOR_END120:%.*]] ; CHECK: for.body106: ; CHECK-NEXT: [[CMP108:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP108]], label [[IF_THEN109:%.*]], label [[FOR_INC117:%.*]] ; CHECK: if.then109: ; CHECK-NEXT: br label [[FOR_INC117]] ; CHECK: for.inc117: ; CHECK-NEXT: br label [[FOR_COND103T]] ; CHECK: for.end120: ; CHECK-NEXT: br label [[FOR_INC159:%.*]] ; CHECK: for.inc159: ; CHECK-NEXT: br label [[FOR_INC163]] ; CHECK: for.inc163: ; CHECK-NEXT: [[CMP12:%.*]] = call zeroext i1 @check() ; CHECK-NEXT: br i1 [[CMP12]], label [[FOR_BODY]], label [[FOR_END166:%.*]] ; CHECK: for.end166: ; CHECK-NEXT: ret void ; entry: br label %for.body for.body: %cmp2113 = call zeroext i1 @check() br i1 %cmp2113, label %for.body22.lr.ph, label %for.inc163 for.body22.lr.ph: br label %for.body22 for.body22: br label %for.body33 for.body33: br label %for.end for.end: %cmp424 = call zeroext i1 @check() br i1 %cmp424, label %for.body43.lr.ph, label %for.end93 for.body43.lr.ph: br label %for.end93 for.end93: %cmp96 = call zeroext i1 @check() br i1 %cmp96, label %if.then97, label %for.cond103 if.then97: br label %for.cond103t for.cond103t: br label %for.cond103 for.cond103: %cmp105 = call zeroext i1 @check() br i1 %cmp105, label %for.body106, label %for.end120 for.body106: %cmp108 = call zeroext i1 @check() br i1 %cmp108, label %if.then109, label %for.inc117 if.then109: br label %for.inc117 for.inc117: br label %for.cond103t for.end120: br label %for.inc159 for.inc159: br i1 false, label %for.body22, label %for.cond15.for.inc163_crit_edge for.cond15.for.inc163_crit_edge: br label %for.inc163 for.inc163: %cmp12 = call zeroext i1 @check() br i1 %cmp12, label %for.body, label %for.end166 for.end166: ret void } ; Remove a loop whose exit branches into a sibling loop. ; Ensure that only the loop is removed and rely on verify-loopinfo to ; check soundness. define void @unloopCriticalEdge() nounwind { ; CHECK-LABEL: @unloopCriticalEdge( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_COND31:%.*]] ; CHECK: for.cond31: ; CHECK-NEXT: br i1 false, label [[FOR_BODY35:%.*]], label [[FOR_END94:%.*]] ; CHECK: for.body35: ; CHECK-NEXT: br label [[WHILE_COND_I_PREHEADER:%.*]] ; CHECK: while.cond.i.preheader: ; CHECK-NEXT: br i1 undef, label [[WHILE_COND_I_PREHEADER_SPLIT:%.*]], label [[WHILE_COND_OUTER_I_LOOPEXIT_SPLIT:%.*]] ; CHECK: while.cond.i.preheader.split: ; CHECK-NEXT: br label [[WHILE_COND_I:%.*]] ; CHECK: while.cond.i: ; CHECK-NEXT: br i1 true, label [[WHILE_COND_I]], label [[WHILE_COND_OUTER_I_LOOPEXIT:%.*]] ; CHECK: while.cond.outer.i.loopexit: ; CHECK-NEXT: br label [[WHILE_COND_OUTER_I_LOOPEXIT_SPLIT]] ; CHECK: while.cond.outer.i.loopexit.split: ; CHECK-NEXT: br label [[WHILE_BODY:%.*]] ; CHECK: while.body: ; CHECK-NEXT: br label [[FOR_END78:%.*]] ; CHECK: for.end78: ; CHECK-NEXT: br i1 false, label [[PROC2_EXIT:%.*]], label [[FOR_COND_I_PREHEADER:%.*]] ; CHECK: for.cond.i.preheader: ; CHECK-NEXT: br label [[FOR_COND_I:%.*]] ; CHECK: for.cond.i: ; CHECK-NEXT: br label [[FOR_COND_I]] ; CHECK: Proc2.exit: ; CHECK-NEXT: unreachable ; CHECK: for.end94: ; CHECK-NEXT: ret void ; entry: br label %for.cond31 for.cond31: br i1 undef, label %for.body35, label %for.end94 for.body35: br label %while.cond.i.preheader while.cond.i.preheader: br i1 undef, label %while.cond.i.preheader.split, label %while.cond.outer.i.loopexit.split while.cond.i.preheader.split: br label %while.cond.i while.cond.i: br i1 true, label %while.cond.i, label %while.cond.outer.i.loopexit while.cond.outer.i.loopexit: br label %while.cond.outer.i.loopexit.split while.cond.outer.i.loopexit.split: br i1 false, label %while.cond.i.preheader, label %Func2.exit Func2.exit: br label %while.body while.body: br i1 false, label %while.body, label %while.end while.end: br label %for.end78 for.end78: br i1 undef, label %Proc2.exit, label %for.cond.i.preheader for.cond.i.preheader: br label %for.cond.i for.cond.i: br label %for.cond.i Proc2.exit: br label %for.cond31 for.end94: ret void } ; Test UnloopUpdater::removeBlocksFromAncestors. ; ; Check that the loop backedge is removed from the middle loop 1699, ; but not the inner loop 1676. define void @removeSubloopBlocks() nounwind { ; CHECK-LABEL: @removeSubloopBlocks( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[TRYAGAIN_OUTER:%.*]] ; CHECK: tryagain.outer: ; CHECK-NEXT: br label [[TRYAGAIN:%.*]] ; CHECK: tryagain: ; CHECK-NEXT: br i1 false, label [[SW_BB1669:%.*]], label [[SW_BB304:%.*]] ; CHECK: sw.bb304: ; CHECK-NEXT: ret void ; CHECK: sw.bb1669: ; CHECK-NEXT: br i1 true, label [[SW_DEFAULT1711:%.*]], label [[WHILE_COND1676_PREHEADER:%.*]] ; CHECK: while.cond1676.preheader: ; CHECK-NEXT: br label [[WHILE_COND1676:%.*]] ; CHECK: while.cond1676: ; CHECK-NEXT: br i1 true, label [[WHILE_END1699:%.*]], label [[WHILE_BODY1694:%.*]] ; CHECK: while.body1694: ; CHECK-NEXT: unreachable ; CHECK: while.end1699: ; CHECK-NEXT: br label [[SW_DEFAULT1711]] ; CHECK: sw.default1711: ; CHECK-NEXT: br label [[DEFCHAR:%.*]] ; CHECK: defchar: ; CHECK-NEXT: br i1 undef, label [[IF_END2413:%.*]], label [[IF_THEN2368:%.*]] ; CHECK: if.then2368: ; CHECK-NEXT: unreachable ; CHECK: if.end2413: ; CHECK-NEXT: unreachable ; entry: br label %tryagain.outer tryagain.outer: ; preds = %sw.bb304, %entry br label %tryagain tryagain: ; preds = %while.end1699, %tryagain.outer br i1 undef, label %sw.bb1669, label %sw.bb304 sw.bb304: ; preds = %tryagain br i1 undef, label %return, label %tryagain.outer sw.bb1669: ; preds = %tryagain br i1 undef, label %sw.default1711, label %while.cond1676 while.cond1676: ; preds = %while.body1694, %sw.bb1669 br i1 undef, label %while.end1699, label %while.body1694 while.body1694: ; preds = %while.cond1676 br label %while.cond1676 while.end1699: ; preds = %while.cond1676 br i1 false, label %tryagain, label %sw.default1711 sw.default1711: ; preds = %while.end1699, %sw.bb1669, %tryagain br label %defchar defchar: ; preds = %sw.default1711, %sw.bb376 br i1 undef, label %if.end2413, label %if.then2368 if.then2368: ; preds = %defchar unreachable if.end2413: ; preds = %defchar unreachable return: ; preds = %sw.bb304 ret void } ; PR11335: the most deeply nested block should be removed from the outer loop. define void @removeSubloopBlocks2() nounwind { ; CHECK-LABEL: @removeSubloopBlocks2( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TOBOOL_I:%.*]] = icmp ne i32 undef, 0 ; CHECK-NEXT: br label [[LBL_616:%.*]] ; CHECK: lbl_616.loopexit: ; CHECK-NEXT: br label [[LBL_616]] ; CHECK: lbl_616: ; CHECK-NEXT: br label [[FOR_COND:%.*]] ; CHECK: for.cond: ; CHECK-NEXT: br i1 false, label [[FOR_COND1_PREHEADER:%.*]], label [[LBL_616_LOOPEXIT:%.*]] ; CHECK: for.cond1.preheader: ; CHECK-NEXT: br label [[FOR_COND1:%.*]] ; CHECK: for.cond1.loopexit: ; CHECK-NEXT: unreachable ; CHECK: for.cond1: ; CHECK-NEXT: br i1 false, label [[FOR_BODY2:%.*]], label [[FOR_COND3:%.*]] ; CHECK: for.body2: ; CHECK-NEXT: br label [[FOR_COND_I:%.*]] ; CHECK: for.cond.i: ; CHECK-NEXT: br i1 [[TOBOOL_I]], label [[FOR_COND_I]], label [[FOR_COND1_LOOPEXIT:%.*]] ; CHECK: for.cond3: ; CHECK-NEXT: ret void ; entry: %tobool.i = icmp ne i32 undef, 0 br label %lbl_616 lbl_616.loopexit: ; preds = %for.cond br label %lbl_616 lbl_616: ; preds = %lbl_616.loopexit, %entry br label %for.cond for.cond: ; preds = %for.cond3, %lbl_616 br i1 false, label %for.cond1.preheader, label %lbl_616.loopexit for.cond1.preheader: ; preds = %for.cond br label %for.cond1 for.cond1.loopexit: ; preds = %for.cond.i br label %for.cond1 for.cond1: ; preds = %for.cond1.loopexit, %for.cond1.preheader br i1 false, label %for.body2, label %for.cond3 for.body2: ; preds = %for.cond1 br label %for.cond.i for.cond.i: ; preds = %for.cond.i, %for.body2 br i1 %tobool.i, label %for.cond.i, label %for.cond1.loopexit for.cond3: ; preds = %for.cond1 br i1 false, label %for.cond, label %if.end if.end: ; preds = %for.cond3 ret void }