1; RUN: opt -passes='loop-vectorize' -debug -S < %s 2>&1 | FileCheck %s 2; REQUIRES: asserts 3 4; This checks we don't crash when the inner loop we're trying to vectorize 5; is a SCEV AddRec with respect to an outer loop. 6 7; In this case, the problematic PHI is: 8; %0 = phi i32 [ poison, %for.cond1.preheader ], [ %inc54, %for.body3 ] 9; Since %inc54 is the IV of the outer loop, and %0 equivalent to it, 10; we get the situation described above. 11 12; Code that leads to this situation can look something like: 13; 14; int a, b[1], c; 15; void fn1 () 16; { 17; for (; c; c++) 18; for (a = 0; a; a++) 19; b[c] = 4; 20; } 21; 22; The PHI is an artifact of the register promotion of c. 23 24; Note that we can no longer get the vectorizer to actually see such PHIs, 25; because LV now simplifies the loop internally, but the test is still 26; useful as a regression test, and in case loop-simplify behavior changes. 27 28@c = external global i32, align 4 29@a = external global i32, align 4 30@b = external global [1 x i32], align 4 31 32; We can vectorize this loop because we are storing an invariant value into an 33; invariant address. 34 35; CHECK: LV: We can vectorize this loop! 36; CHECK-LABEL: @test 37define void @test() { 38entry: 39 %a.promoted2 = load i32, ptr @a, align 1 40 %c.promoted = load i32, ptr @c, align 1 41 br label %for.cond1.preheader 42 43for.cond1.preheader: ; preds = %for.cond1.for.inc4_crit_edge, %entry 44 %inc54 = phi i32 [ %inc5, %for.cond1.for.inc4_crit_edge ], [ %c.promoted, %entry ] 45 %inc.lcssa3 = phi i32 [ %inc.lcssa, %for.cond1.for.inc4_crit_edge ], [ %a.promoted2, %entry ] 46 br label %for.body3 47 48for.body3: ; preds = %for.body3, %for.cond1.preheader 49 %inc1 = phi i32 [ %inc.lcssa3, %for.cond1.preheader ], [ %inc, %for.body3 ] 50 %0 = phi i32 [ poison, %for.cond1.preheader ], [ %inc54, %for.body3 ] 51 %idxprom = sext i32 %0 to i64 52 %arrayidx = getelementptr inbounds [1 x i32], ptr @b, i64 0, i64 %idxprom 53 store i32 4, ptr %arrayidx, align 4 54 %inc = add nsw i32 %inc1, 1 55 %tobool2 = icmp eq i32 %inc, 0 56 br i1 %tobool2, label %for.cond1.for.inc4_crit_edge, label %for.body3 57 58for.cond1.for.inc4_crit_edge: ; preds = %for.body3 59 %inc.lcssa = phi i32 [ %inc, %for.body3 ] 60 %.lcssa = phi i32 [ %inc54, %for.body3 ] 61 %inc5 = add nsw i32 %.lcssa, 1 62 br label %for.cond1.preheader 63} 64