1; RUN: opt -loop-reduce -S < %s | FileCheck %s 2; 3; <rdar://10619599> "SelectionDAGBuilder shouldn't visit PHI nodes!" assert. 4; <rdar://10655343> SCEVExpander segfault on simple test case 5 6target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-f128:128:128-n8:16:32" 7target triple = "i386-apple-darwin" 8 9; LSR should convert the inner loop (bb7.us) IV (j.01.us) into float*. 10; This involves a nested AddRec, the outer AddRec's loop invariant components 11; cannot find a preheader, so they should be expanded in the loop header 12; (bb7.lr.ph.us) below the existing phi i.12.us. 13; Currently, LSR won't kick in on such loops. 14; CHECK-LABEL: @nopreheader( 15; CHECK: bb7.us: 16; CHECK-NOT: phi float* 17; CHECK: %j.01.us = phi i32 18; CHECK-NOT: phi float* 19define void @nopreheader(float* nocapture %a, i32 %n) nounwind { 20entry: 21 %0 = sdiv i32 %n, undef 22 indirectbr i8* undef, [label %bb10.preheader] 23 24bb10.preheader: ; preds = %bb4 25 indirectbr i8* undef, [label %bb8.preheader.lr.ph, label %return] 26 27bb8.preheader.lr.ph: ; preds = %bb10.preheader 28 indirectbr i8* null, [label %bb7.lr.ph.us, label %bb9] 29 30bb7.lr.ph.us: ; preds = %bb9.us, %bb8.preheader.lr.ph 31 %i.12.us = phi i32 [ %2, %bb9.us ], [ 0, %bb8.preheader.lr.ph ] 32 %tmp30 = mul i32 %0, %i.12.us 33 indirectbr i8* undef, [label %bb7.us] 34 35bb7.us: ; preds = %bb7.lr.ph.us, %bb7.us 36 %j.01.us = phi i32 [ 0, %bb7.lr.ph.us ], [ %1, %bb7.us ] 37 %tmp31 = add i32 %tmp30, %j.01.us 38 %scevgep9 = getelementptr float* %a, i32 %tmp31 39 store float undef, float* %scevgep9, align 1 40 %1 = add nsw i32 %j.01.us, 1 41 indirectbr i8* undef, [label %bb9.us, label %bb7.us] 42 43bb9.us: ; preds = %bb7.us 44 %2 = add nsw i32 %i.12.us, 1 45 indirectbr i8* undef, [label %bb7.lr.ph.us, label %return] 46 47bb9: ; preds = %bb9, %bb8.preheader.lr.ph 48 indirectbr i8* undef, [label %bb9, label %return] 49 50return: ; preds = %bb9, %bb9.us, %bb10.preheader 51 ret void 52} 53 54; In this case, SCEVExpander simply cannot materialize the AddRecExpr 55; that LSR picks. We must detect that %bb8.preheader does not have a 56; preheader and avoid performing LSR on %bb7. 57; CHECK-LABEL: @nopreheader2( 58; CHECK: bb7: 59; CHECK: %indvar = phi i32 60define fastcc void @nopreheader2([200 x i32]* nocapture %Array2) nounwind { 61entry: 62 indirectbr i8* undef, [label %bb] 63 64bb: ; preds = %bb, %entry 65 indirectbr i8* undef, [label %bb3, label %bb] 66 67bb3: ; preds = %bb3, %bb 68 indirectbr i8* undef, [label %bb8.preheader, label %bb3] 69 70bb8.preheader: ; preds = %bb9, %bb3 71 %indvar5 = phi i32 [ %indvar.next6, %bb9 ], [ 0, %bb3 ] 72 %tmp26 = add i32 %indvar5, 13 73 indirectbr i8* null, [label %bb7] 74 75bb7: ; preds = %bb8.preheader, %bb7 76 %indvar = phi i32 [ 0, %bb8.preheader ], [ %indvar.next, %bb7 ] 77 %scevgep = getelementptr [200 x i32]* %Array2, i32 %tmp26, i32 %indvar 78 store i32 undef, i32* %scevgep, align 4 79 %indvar.next = add i32 %indvar, 1 80 indirectbr i8* undef, [label %bb9, label %bb7] 81 82bb9: ; preds = %bb7 83 %indvar.next6 = add i32 %indvar5, 1 84 indirectbr i8* undef, [label %return, label %bb8.preheader] 85 86return: ; preds = %bb9 87 ret void 88} 89