| ; 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 |
| |
| 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 |
| } |