|  | ; RUN: opt -loop-reduce -S < %s | FileCheck %s | 
|  | ; | 
|  | ; <rdar://10619599> "SelectionDAGBuilder shouldn't visit PHI nodes!" assert. | 
|  | ; <rdar://10655343> SCEVExpander segfault on simple test case | 
|  |  | 
|  | target 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" | 
|  | target triple = "i386-apple-darwin" | 
|  |  | 
|  | ; LSR should convert the inner loop (bb7.us) IV (j.01.us) into float*. | 
|  | ; This involves a nested AddRec, the outer AddRec's loop invariant components | 
|  | ; cannot find a preheader, so they should be expanded in the loop header | 
|  | ; (bb7.lr.ph.us) below the existing phi i.12.us. | 
|  | ; Currently, LSR won't kick in on such loops. | 
|  | ; CHECK-LABEL: @nopreheader( | 
|  | ; CHECK: bb7.us: | 
|  | ; CHECK-NOT: phi float* | 
|  | ; CHECK: %j.01.us = phi i32 | 
|  | ; CHECK-NOT: phi float* | 
|  | define void @nopreheader(float* nocapture %a, i32 %n) nounwind { | 
|  | entry: | 
|  | %0 = sdiv i32 %n, undef | 
|  | indirectbr i8* undef, [label %bb10.preheader] | 
|  |  | 
|  | bb10.preheader:                                   ; preds = %bb4 | 
|  | indirectbr i8* undef, [label %bb8.preheader.lr.ph, label %return] | 
|  |  | 
|  | bb8.preheader.lr.ph:                              ; preds = %bb10.preheader | 
|  | indirectbr i8* null, [label %bb7.lr.ph.us, label %bb9] | 
|  |  | 
|  | bb7.lr.ph.us:                                     ; preds = %bb9.us, %bb8.preheader.lr.ph | 
|  | %i.12.us = phi i32 [ %2, %bb9.us ], [ 0, %bb8.preheader.lr.ph ] | 
|  | %tmp30 = mul i32 %0, %i.12.us | 
|  | indirectbr i8* undef, [label %bb7.us] | 
|  |  | 
|  | bb7.us:                                           ; preds = %bb7.lr.ph.us, %bb7.us | 
|  | %j.01.us = phi i32 [ 0, %bb7.lr.ph.us ], [ %1, %bb7.us ] | 
|  | %tmp31 = add i32 %tmp30, %j.01.us | 
|  | %scevgep9 = getelementptr float, float* %a, i32 %tmp31 | 
|  | store float undef, float* %scevgep9, align 1 | 
|  | %1 = add nsw i32 %j.01.us, 1 | 
|  | indirectbr i8* undef, [label %bb9.us, label %bb7.us] | 
|  |  | 
|  | bb9.us:                                           ; preds = %bb7.us | 
|  | %2 = add nsw i32 %i.12.us, 1 | 
|  | indirectbr i8* undef, [label %bb7.lr.ph.us, label %return] | 
|  |  | 
|  | bb9:                                              ; preds = %bb9, %bb8.preheader.lr.ph | 
|  | indirectbr i8* undef, [label %bb9, label %return] | 
|  |  | 
|  | return:                                           ; preds = %bb9, %bb9.us, %bb10.preheader | 
|  | ret void | 
|  | } | 
|  |  | 
|  | ; In this case, SCEVExpander simply cannot materialize the AddRecExpr | 
|  | ; that LSR picks. We must detect that %bb8.preheader does not have a | 
|  | ; preheader and avoid performing LSR on %bb7. | 
|  | ; CHECK-LABEL: @nopreheader2( | 
|  | ; CHECK: bb7: | 
|  | ; CHECK: %indvar = phi i32 | 
|  | define fastcc void @nopreheader2([200 x i32]* nocapture %Array2) nounwind { | 
|  | entry: | 
|  | indirectbr i8* undef, [label %bb] | 
|  |  | 
|  | bb:                                               ; preds = %bb, %entry | 
|  | indirectbr i8* undef, [label %bb3, label %bb] | 
|  |  | 
|  | bb3:                                              ; preds = %bb3, %bb | 
|  | indirectbr i8* undef, [label %bb8.preheader, label %bb3] | 
|  |  | 
|  | bb8.preheader:                                    ; preds = %bb9, %bb3 | 
|  | %indvar5 = phi i32 [ %indvar.next6, %bb9 ], [ 0, %bb3 ] | 
|  | %tmp26 = add i32 %indvar5, 13 | 
|  | indirectbr i8* null, [label %bb7] | 
|  |  | 
|  | bb7:                                              ; preds = %bb8.preheader, %bb7 | 
|  | %indvar = phi i32 [ 0, %bb8.preheader ], [ %indvar.next, %bb7 ] | 
|  | %scevgep = getelementptr [200 x i32], [200 x i32]* %Array2, i32 %tmp26, i32 %indvar | 
|  | store i32 undef, i32* %scevgep, align 4 | 
|  | %indvar.next = add i32 %indvar, 1 | 
|  | indirectbr i8* undef, [label %bb9, label %bb7] | 
|  |  | 
|  | bb9:                                              ; preds = %bb7 | 
|  | %indvar.next6 = add i32 %indvar5, 1 | 
|  | indirectbr i8* undef, [label %return, label %bb8.preheader] | 
|  |  | 
|  | return:                                           ; preds = %bb9 | 
|  | ret void | 
|  | } |