1; RUN: opt < %s -loop-vectorize -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7-avx -force-vector-width=4 -force-vector-interleave=0 -dce -S \ 2; RUN: | FileCheck %s --check-prefix=CHECK-VECTOR 3; RUN: opt < %s -loop-vectorize -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7-avx -force-vector-width=1 -force-vector-interleave=0 -dce -S \ 4; RUN: | FileCheck %s --check-prefix=CHECK-SCALAR 5 6target 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" 7target triple = "x86_64-apple-macosx10.8.0" 8 9; We don't unroll this loop because it has a small constant trip count. 10; 11; CHECK-VECTOR-LABEL: @foo( 12; CHECK-VECTOR: load <4 x i32> 13; CHECK-VECTOR-NOT: load <4 x i32> 14; CHECK-VECTOR: store <4 x i32> 15; CHECK-VECTOR-NOT: store <4 x i32> 16; CHECK-VECTOR: ret 17; 18; CHECK-SCALAR-LABEL: @foo( 19; CHECK-SCALAR: load i32, i32* 20; CHECK-SCALAR-NOT: load i32, i32* 21; CHECK-SCALAR: store i32 22; CHECK-SCALAR-NOT: store i32 23; CHECK-SCALAR: ret 24define i32 @foo(i32* nocapture %A) nounwind uwtable ssp { 25 br label %1 26 27; <label>:1 ; preds = %1, %0 28 %indvars.iv = phi i64 [ 0, %0 ], [ %indvars.iv.next, %1 ] 29 %2 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv 30 %3 = load i32, i32* %2, align 4 31 %4 = add nsw i32 %3, 6 32 store i32 %4, i32* %2, align 4 33 %indvars.iv.next = add i64 %indvars.iv, 1 34 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 35 %exitcond = icmp eq i32 %lftr.wideiv, 100 36 br i1 %exitcond, label %5, label %1 37 38; <label>:5 ; preds = %1 39 ret i32 undef 40} 41 42; But this is a good small loop to unroll as we don't know of a bound on its 43; trip count. 44; 45; CHECK-VECTOR-LABEL: @bar( 46; CHECK-VECTOR: store <4 x i32> 47; CHECK-VECTOR: store <4 x i32> 48; CHECK-VECTOR: ret 49; 50; For x86, loop unroll in loop vectorizer is disabled when VF==1. 51; 52; CHECK-SCALAR-LABEL: @bar( 53; CHECK-SCALAR: store i32 54; CHECK-SCALAR-NOT: store i32 55; CHECK-SCALAR: ret 56define i32 @bar(i32* nocapture %A, i32 %n) nounwind uwtable ssp { 57 %1 = icmp sgt i32 %n, 0 58 br i1 %1, label %.lr.ph, label %._crit_edge 59 60.lr.ph: ; preds = %0, %.lr.ph 61 %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %0 ] 62 %2 = getelementptr inbounds i32, i32* %A, i64 %indvars.iv 63 %3 = load i32, i32* %2, align 4 64 %4 = add nsw i32 %3, 6 65 store i32 %4, i32* %2, align 4 66 %indvars.iv.next = add i64 %indvars.iv, 1 67 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 68 %exitcond = icmp eq i32 %lftr.wideiv, %n 69 br i1 %exitcond, label %._crit_edge, label %.lr.ph 70 71._crit_edge: ; preds = %.lr.ph, %0 72 ret i32 undef 73} 74 75; Also unroll if we need a runtime check but it was going to be added for 76; vectorization anyways. 77; CHECK-VECTOR-LABEL: @runtime_chk( 78; CHECK-VECTOR: store <4 x float> 79; CHECK-VECTOR: store <4 x float> 80; 81; But not if the unrolling would introduce the runtime check. 82; CHECK-SCALAR-LABEL: @runtime_chk( 83; CHECK-SCALAR: store float 84; CHECK-SCALAR-NOT: store float 85define void @runtime_chk(float* %A, float* %B, float %N) { 86entry: 87 br label %for.body 88 89for.body: 90 %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] 91 %arrayidx = getelementptr inbounds float, float* %B, i64 %indvars.iv 92 %0 = load float, float* %arrayidx, align 4 93 %mul = fmul float %0, %N 94 %arrayidx2 = getelementptr inbounds float, float* %A, i64 %indvars.iv 95 store float %mul, float* %arrayidx2, align 4 96 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 97 %exitcond = icmp eq i64 %indvars.iv.next, 256 98 br i1 %exitcond, label %for.end, label %for.body 99 100for.end: 101 ret void 102} 103