; RUN: opt -S -loop-vectorize -force-vector-width=8 -force-vector-interleave=1 < %s | FileCheck %s -check-prefix=VF8 ; RUN: opt -S -loop-vectorize -force-vector-width=1 -force-vector-interleave=4 < %s | FileCheck %s -check-prefix=VF1 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" ; Given a loop with an induction variable which is being ; truncated/extended using casts that had been proven to ; be redundant under a runtime test, we want to make sure ; that these casts, do not get vectorized/scalarized/widened. ; This is the case for inductions whose SCEV expression is ; of the form "ExtTrunc(%phi) + %step", where "ExtTrunc" ; can be a result of the IR sequences we check below. ; ; See also pr30654. ; ; Case1: Check the following induction pattern: ; ; %p.09 = phi i32 [ 0, %for.body.lr.ph ], [ %add, %for.body ] ; %sext = shl i32 %p.09, 24 ; %conv = ashr exact i32 %sext, 24 ; %add = add nsw i32 %conv, %step ; ; This is the case in the following code: ; ; void doit1(int n, int step) { ; int i; ; char p = 0; ; for (i = 0; i < n; i++) { ; a[i] = p; ; p = p + step; ; } ; } ; ; The "ExtTrunc" IR sequence here is: ; "%sext = shl i32 %p.09, 24" ; "%conv = ashr exact i32 %sext, 24" ; We check that it does not appear in the vector loop body, whether ; we vectorize or scalarize the induction. ; In the case of widened induction, this means that the induction phi ; is directly used, without shl/ashr on the way. ; VF8-LABEL: @doit1 ; VF8: vector.body: ; VF8: %vec.ind = phi <8 x i32> ; VF8: store <8 x i32> %vec.ind ; VF8: middle.block: ; VF1-LABEL: @doit1 ; VF1: vector.body: ; VF1-NOT: %{{.*}} = shl i32 ; VF1: middle.block: @a = common local_unnamed_addr global [250 x i32] zeroinitializer, align 16 define void @doit1(i32 %n, i32 %step) { entry: %cmp7 = icmp sgt i32 %n, 0 br i1 %cmp7, label %for.body.lr.ph, label %for.end for.body.lr.ph: %wide.trip.count = zext i32 %n to i64 br label %for.body for.body: %indvars.iv = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next, %for.body ] %p.09 = phi i32 [ 0, %for.body.lr.ph ], [ %add, %for.body ] %sext = shl i32 %p.09, 24 %conv = ashr exact i32 %sext, 24 %arrayidx = getelementptr inbounds [250 x i32], [250 x i32]* @a, i64 0, i64 %indvars.iv store i32 %conv, i32* %arrayidx, align 4 %add = add nsw i32 %conv, %step %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count br i1 %exitcond, label %for.end.loopexit, label %for.body for.end.loopexit: br label %for.end for.end: ret void } ; Case2: Another variant of the above pattern is where the induction variable ; is used only for address compuation (i.e. it is a GEP index) and therefore ; the induction is not vectorized but rather only the step is widened. ; ; This is the case in the following code, where the induction variable 'w_ix' ; is only used to access the array 'in': ; ; void doit2(int *in, int *out, size_t size, size_t step) ; { ; int w_ix = 0; ; for (size_t offset = 0; offset < size; ++offset) ; { ; int w = in[w_ix]; ; out[offset] = w; ; w_ix += step; ; } ; } ; ; The "ExtTrunc" IR sequence here is similar to the previous case: ; "%sext = shl i64 %w_ix.012, 32 ; %idxprom = ashr exact i64 %sext, 32" ; We check that it does not appear in the vector loop body, whether ; we widen or scalarize the induction. ; In the case of widened induction, this means that the induction phi ; is directly used, without shl/ashr on the way. ; VF8-LABEL: @doit2 ; VF8: vector.body: ; VF8: %vec.ind = phi <8 x i64> ; VF8: %{{.*}} = extractelement <8 x i64> %vec.ind ; VF8: middle.block: ; VF1-LABEL: @doit2 ; VF1: vector.body: ; VF1-NOT: %{{.*}} = shl i64 ; VF1: middle.block: ; define void @doit2(i32* nocapture readonly %in, i32* nocapture %out, i64 %size, i64 %step) { entry: %cmp9 = icmp eq i64 %size, 0 br i1 %cmp9, label %for.cond.cleanup, label %for.body.lr.ph for.body.lr.ph: br label %for.body for.cond.cleanup.loopexit: br label %for.cond.cleanup for.cond.cleanup: ret void for.body: %w_ix.011 = phi i64 [ 0, %for.body.lr.ph ], [ %add, %for.body ] %offset.010 = phi i64 [ 0, %for.body.lr.ph ], [ %inc, %for.body ] %sext = shl i64 %w_ix.011, 32 %idxprom = ashr exact i64 %sext, 32 %arrayidx = getelementptr inbounds i32, i32* %in, i64 %idxprom %0 = load i32, i32* %arrayidx, align 4 %arrayidx1 = getelementptr inbounds i32, i32* %out, i64 %offset.010 store i32 %0, i32* %arrayidx1, align 4 %add = add i64 %idxprom, %step %inc = add nuw i64 %offset.010, 1 %exitcond = icmp eq i64 %inc, %size br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body } ; Case3: Lastly, check also the following induction pattern: ; ; %p.09 = phi i32 [ %val0, %scalar.ph ], [ %add, %for.body ] ; %conv = and i32 %p.09, 255 ; %add = add nsw i32 %conv, %step ; ; This is the case in the following code: ; ; int a[N]; ; void doit3(int n, int step) { ; int i; ; unsigned char p = 0; ; for (i = 0; i < n; i++) { ; a[i] = p; ; p = p + step; ; } ; } ; ; The "ExtTrunc" IR sequence here is: ; "%conv = and i32 %p.09, 255". ; We check that it does not appear in the vector loop body, whether ; we vectorize or scalarize the induction. ; VF8-LABEL: @doit3 ; VF8: vector.body: ; VF8: %vec.ind = phi <8 x i32> ; VF8: store <8 x i32> %vec.ind ; VF8: middle.block: ; VF1-LABEL: @doit3 ; VF1: vector.body: ; VF1-NOT: %{{.*}} = and i32 ; VF1: middle.block: define void @doit3(i32 %n, i32 %step) { entry: %cmp7 = icmp sgt i32 %n, 0 br i1 %cmp7, label %for.body.lr.ph, label %for.end for.body.lr.ph: %wide.trip.count = zext i32 %n to i64 br label %for.body for.body: %indvars.iv = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next, %for.body ] %p.09 = phi i32 [ 0, %for.body.lr.ph ], [ %add, %for.body ] %conv = and i32 %p.09, 255 %arrayidx = getelementptr inbounds [250 x i32], [250 x i32]* @a, i64 0, i64 %indvars.iv store i32 %conv, i32* %arrayidx, align 4 %add = add nsw i32 %conv, %step %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count br i1 %exitcond, label %for.end.loopexit, label %for.body for.end.loopexit: br label %for.end for.end: ret void }