| ; RUN: opt -passes='loop-vectorize' -debug -S < %s 2>&1 | FileCheck %s |
| ; REQUIRES: asserts |
| |
| ; This checks we don't crash when the inner loop we're trying to vectorize |
| ; is a SCEV AddRec with respect to an outer loop. |
| |
| ; In this case, the problematic PHI is: |
| ; %0 = phi i32 [ undef, %for.cond1.preheader ], [ %inc54, %for.body3 ] |
| ; Since %inc54 is the IV of the outer loop, and %0 equivalent to it, |
| ; we get the situation described above. |
| |
| ; Code that leads to this situation can look something like: |
| ; |
| ; int a, b[1], c; |
| ; void fn1 () |
| ; { |
| ; for (; c; c++) |
| ; for (a = 0; a; a++) |
| ; b[c] = 4; |
| ; } |
| ; |
| ; The PHI is an artifact of the register promotion of c. |
| |
| ; Note that we can no longer get the vectorizer to actually see such PHIs, |
| ; because LV now simplifies the loop internally, but the test is still |
| ; useful as a regression test, and in case loop-simplify behavior changes. |
| |
| @c = external global i32, align 4 |
| @a = external global i32, align 4 |
| @b = external global [1 x i32], align 4 |
| |
| ; We can vectorize this loop because we are storing an invariant value into an |
| ; invariant address. |
| |
| ; CHECK: LV: We can vectorize this loop! |
| ; CHECK-LABEL: @test |
| define void @test() { |
| entry: |
| %a.promoted2 = load i32, i32* @a, align 1 |
| %c.promoted = load i32, i32* @c, align 1 |
| br label %for.cond1.preheader |
| |
| for.cond1.preheader: ; preds = %for.cond1.for.inc4_crit_edge, %entry |
| %inc54 = phi i32 [ %inc5, %for.cond1.for.inc4_crit_edge ], [ %c.promoted, %entry ] |
| %inc.lcssa3 = phi i32 [ %inc.lcssa, %for.cond1.for.inc4_crit_edge ], [ %a.promoted2, %entry ] |
| br label %for.body3 |
| |
| for.body3: ; preds = %for.body3, %for.cond1.preheader |
| %inc1 = phi i32 [ %inc.lcssa3, %for.cond1.preheader ], [ %inc, %for.body3 ] |
| %0 = phi i32 [ undef, %for.cond1.preheader ], [ %inc54, %for.body3 ] |
| %idxprom = sext i32 %0 to i64 |
| %arrayidx = getelementptr inbounds [1 x i32], [1 x i32]* @b, i64 0, i64 %idxprom |
| store i32 4, i32* %arrayidx, align 4 |
| %inc = add nsw i32 %inc1, 1 |
| %tobool2 = icmp eq i32 %inc, 0 |
| br i1 %tobool2, label %for.cond1.for.inc4_crit_edge, label %for.body3 |
| |
| for.cond1.for.inc4_crit_edge: ; preds = %for.body3 |
| %inc.lcssa = phi i32 [ %inc, %for.body3 ] |
| %.lcssa = phi i32 [ %inc54, %for.body3 ] |
| %inc5 = add nsw i32 %.lcssa, 1 |
| br label %for.cond1.preheader |
| } |