1 ; RUN: opt -S < %s -loop-idiom | FileCheck %s 2 ; CHECK-NOT: memset 3 ; check that memset is not generated (for stores) because that will result 4 ; in udiv hoisted out of the loop by the SCEV Expander 5 ; TODO: ideally we should be able to generate memset 6 ; if SCEV expander is taught to generate the dependencies 7 ; at the right point. 8 9 @a = global i32 0, align 4 10 @b = global i32 0, align 4 11 @c = external local_unnamed_addr global [1 x i8], align 1 12 13 define void @e() local_unnamed_addr { 14 entry: 15 %d0 = load i32, i32* @a, align 4 16 %d1 = load i32, i32* @b, align 4 17 br label %for.cond1thread-pre-split 18 19 for.cond1thread-pre-split: ; preds = %for.body5, %entry 20 %div = udiv i32 %d0, %d1 21 br label %for.body5 22 23 for.body5: ; preds = %for.body5, %for.cond1thread-pre-split 24 %indvars.iv = phi i64 [ 0, %for.cond1thread-pre-split ], [ %indvars.iv.next, %for.body5 ] 25 %divx = sext i32 %div to i64 26 %0 = add nsw i64 %divx, %indvars.iv 27 %arrayidx = getelementptr inbounds [1 x i8], [1 x i8]* @c, i64 0, i64 %0 28 store i8 0, i8* %arrayidx, align 1 29 %indvars.iv.next = add nsw i64 %indvars.iv, 1 30 %1 = trunc i64 %indvars.iv.next to i32 31 %tobool4 = icmp eq i32 %1, 0 32 br i1 %tobool4, label %for.cond1thread-pre-split, label %for.body5 33 } 34 35 ; The loop's trip count is depending on an unsafe operation 36 ; udiv. SCEV expander hoists it out of the loop, so loop-idiom 37 ; should check that the memset is not generated in this case. 38 define void @f(i32 %a, i32 %b, i8* nocapture %x) local_unnamed_addr { 39 entry: 40 br label %for.body 41 42 for.body: ; preds = %for.body6, %entry 43 %div = udiv i32 %a, %b 44 %conv = zext i32 %div to i64 45 br label %for.body6 46 47 for.body6: ; preds = %for.body6, %for.body 48 %i.09 = phi i64 [ %inc, %for.body6 ], [ 0, %for.body ] 49 %arrayidx = getelementptr inbounds i8, i8* %x, i64 %i.09 50 store i8 0, i8* %arrayidx, align 1 51 %inc = add nuw nsw i64 %i.09, 1 52 %cmp3 = icmp slt i64 %inc, %conv 53 br i1 %cmp3, label %for.body6, label %for.body 54 } 55 56
