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| ; RUN: opt < %s -loop-vectorize -force-vector-width=2 -force-vector-interleave=1 -S | FileCheck %s
; RUN: opt < %s -loop-vectorize -force-vector-width=4 -force-vector-interleave=1 -S | FileCheck %s -check-prefix=WIDTH
; RUN: opt -S -loop-vectorize -force-vector-width=4 < %s | FileCheck %s -check-prefix=RIGHTVF
; RUN: opt -S -loop-vectorize -force-vector-width=8 < %s | FileCheck %s -check-prefix=WRONGVF
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
; Vectorization with dependence checks.
; No plausible dependence - can be vectorized.
; for (i = 0; i < 1024; ++i)
; A[i] = A[i + 1] + 1;
; CHECK-LABEL: @f1_vec(
; CHECK: <2 x i32>
define void @f1_vec(i32* %A) {
entry:
br label %for.body
for.body:
%indvars.iv = phi i32 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%indvars.iv.next = add i32 %indvars.iv, 1
%arrayidx = getelementptr inbounds i32, i32* %A, i32 %indvars.iv.next
%0 = load i32, i32* %arrayidx, align 4
%add1 = add nsw i32 %0, 1
%arrayidx3 = getelementptr inbounds i32, i32* %A, i32 %indvars.iv
store i32 %add1, i32* %arrayidx3, align 4
%exitcond = icmp ne i32 %indvars.iv.next, 1024
br i1 %exitcond, label %for.body, label %for.end
for.end:
ret void
}
; Plausible dependence of distance 1 - can't be vectorized.
; for (i = 0; i < 1024; ++i)
; A[i+1] = A[i] + 1;
; CHECK-LABEL: @f2_novec(
; CHECK-NOT: <2 x i32>
define void @f2_novec(i32* %A) {
entry:
br label %for.body
for.body:
%indvars.iv = phi i32 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32, i32* %A, i32 %indvars.iv
%0 = load i32, i32* %arrayidx, align 4
%add = add nsw i32 %0, 1
%indvars.iv.next = add i32 %indvars.iv, 1
%arrayidx3 = getelementptr inbounds i32, i32* %A, i32 %indvars.iv.next
store i32 %add, i32* %arrayidx3, align 4
%exitcond = icmp ne i32 %indvars.iv.next, 1024
br i1 %exitcond, label %for.body, label %for.end
for.end:
ret void
}
; Plausible dependence of distance 2 - can be vectorized with a width of 2.
; for (i = 0; i < 1024; ++i)
; A[i+2] = A[i] + 1;
; CHECK-LABEL: @f3_vec_len(
; CHECK: <2 x i32>
; WIDTH: f3_vec_len
; WIDTH-NOT: <4 x i32>
define void @f3_vec_len(i32* %A) {
entry:
br label %for.body
for.body:
%i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%idxprom = sext i32 %i.01 to i64
%arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom
%0 = load i32, i32* %arrayidx, align 4
%add = add nsw i32 %0, 1
%add1 = add nsw i32 %i.01, 2
%idxprom2 = sext i32 %add1 to i64
%arrayidx3 = getelementptr inbounds i32, i32* %A, i64 %idxprom2
store i32 %add, i32* %arrayidx3, align 4
%inc = add nsw i32 %i.01, 1
%cmp = icmp slt i32 %inc, 1024
br i1 %cmp, label %for.body, label %for.end
for.end:
ret void
}
; Plausible dependence of distance 1 - cannot be vectorized (without reordering
; accesses).
; for (i = 0; i < 1024; ++i) {
; B[i] = A[i];
; A[i] = B[i + 1];
; }
; CHECK-LABEL: @f5(
; CHECK-NOT: <2 x i32>
define void @f5(i32* %A, i32* %B) {
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
%0 = load i32, i32* %arrayidx, align 4
%arrayidx2 = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
store i32 %0, i32* %arrayidx2, align 4
%indvars.iv.next = add nsw i64 %indvars.iv, 1
%arrayidx4 = getelementptr inbounds i32, i32* %B, i64 %indvars.iv.next
%1 = load i32, i32* %arrayidx4, align 4
store i32 %1, i32* %arrayidx, align 4
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp ne i32 %lftr.wideiv, 1024
br i1 %exitcond, label %for.body, label %for.end
for.end:
ret void
}
; Dependence through a phi node - must not vectorize.
; for (i = 0; i < 1024; ++i) {
; a[i+1] = tmp;
; tmp = a[i];
; }
; CHECK-LABEL: @f6
; CHECK-NOT: <2 x i32>
define i32 @f6(i32* %a, i32 %tmp) {
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%tmp.addr.08 = phi i32 [ %tmp, %entry ], [ %0, %for.body ]
%indvars.iv.next = add nsw i64 %indvars.iv, 1
%arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv.next
store i32 %tmp.addr.08, i32* %arrayidx, align 4
%arrayidx3 = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
%0 = load i32, i32* %arrayidx3, align 4
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp ne i32 %lftr.wideiv, 1024
br i1 %exitcond, label %for.body, label %for.end
for.end:
ret i32 undef
}
; Don't vectorize true loop carried dependencies that are not a multiple of the
; vector width.
; Example:
; for (int i = ...; ++i) {
; a[i] = a[i-3] + ...;
; It is a bad idea to vectorize this loop because store-load forwarding will not
; happen.
;
; CHECK-LABEL: @nostoreloadforward(
; CHECK-NOT: <2 x i32>
define void @nostoreloadforward(i32* %A) {
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 16, %entry ], [ %indvars.iv.next, %for.body ]
%0 = add nsw i64 %indvars.iv, -3
%arrayidx = getelementptr inbounds i32, i32* %A, i64 %0
%1 = load i32, i32* %arrayidx, align 4
%2 = add nsw i64 %indvars.iv, 4
%arrayidx2 = getelementptr inbounds i32, i32* %A, i64 %2
%3 = load i32, i32* %arrayidx2, align 4
%add3 = add nsw i32 %3, %1
%arrayidx5 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
store i32 %add3, i32* %arrayidx5, align 4
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp ne i32 %lftr.wideiv, 128
br i1 %exitcond, label %for.body, label %for.end
for.end:
ret void
}
; Example:
; for (int i = ...; ++i) {
; a[i] = b[i];
; c[i] = a[i-3] + ...;
; It is a bad idea to vectorize this loop because store-load forwarding will not
; happen.
;
; CHECK-LABEL: @nostoreloadforward2(
; CHECK-NOT: <2 x i32>
define void @nostoreloadforward2(i32* noalias %A, i32* noalias %B, i32* noalias %C) {
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 16, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
%0 = load i32, i32* %arrayidx, align 4
%arrayidx2 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
store i32 %0, i32* %arrayidx2, align 4
%1 = add nsw i64 %indvars.iv, -3
%arrayidx4 = getelementptr inbounds i32, i32* %A, i64 %1
%2 = load i32, i32* %arrayidx4, align 4
%arrayidx6 = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
store i32 %2, i32* %arrayidx6, align 4
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp ne i32 %lftr.wideiv, 128
br i1 %exitcond, label %for.body, label %for.end
for.end:
ret void
}
;Check the new calculation of the maximum safe distance in bits which can be vectorized.
;The previous behavior did not take account that the stride was 2.
;Therefore the maxVF was computed as 8 instead of 4, as the dependence distance here is 6 iterations, given by |N-(N-12)|/2.
;#define M 32
;#define N 2 * M
;unsigned int a [N];
;void pr34283(){
; unsigned int j=0;
; for (j = 0; j < M - 6; ++j)
; {
; a[N - 2 * j] = 69;
; a[N - 12 - 2 * j] = 7;
; }
;
;}
; RIGHTVF-LABEL: @pr34283
; RIGHTVF: <4 x i64>
; WRONGVF-LABLE: @pr34283
; WRONGVF-NOT: <8 x i64>
@a = common local_unnamed_addr global [64 x i32] zeroinitializer, align 16
; Function Attrs: norecurse nounwind uwtable
define void @pr34283() local_unnamed_addr {
entry:
br label %for.body
for.body:
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%0 = shl i64 %indvars.iv, 1
%1 = sub nuw nsw i64 64, %0
%arrayidx = getelementptr inbounds [64 x i32], [64 x i32]* @a, i64 0, i64 %1
store i32 69, i32* %arrayidx, align 8
%2 = sub nuw nsw i64 52, %0
%arrayidx4 = getelementptr inbounds [64 x i32], [64 x i32]* @a, i64 0, i64 %2
store i32 7, i32* %arrayidx4, align 8
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%exitcond = icmp eq i64 %indvars.iv.next, 26
br i1 %exitcond, label %for.end, label %for.body
for.end:
ret void
}
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