; RUN: opt < %s -loop-vectorize -force-vector-unroll=1 -force-vector-width=4 -dce -instcombine -S -enable-if-conversion | FileCheck %s 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" target triple = "x86_64-apple-macosx10.9.0" ; This is kernel11 from "LivermoreLoops". We can't vectorize it because we ; access both x[k] and x[k-1]. ; ; void kernel11(double *x, double *y, int n) { ; for ( int k=1 ; k<n ; k++ ) ; x[k] = x[k-1] + y[k]; ; } ; CHECK-LABEL: @kernel11( ; CHECK-NOT: <4 x double> ; CHECK: ret define i32 @kernel11(double* %x, double* %y, i32 %n) nounwind uwtable ssp { %1 = alloca double*, align 8 %2 = alloca double*, align 8 %3 = alloca i32, align 4 %k = alloca i32, align 4 store double* %x, double** %1, align 8 store double* %y, double** %2, align 8 store i32 %n, i32* %3, align 4 store i32 1, i32* %k, align 4 br label %4 ; <label>:4 ; preds = %25, %0 %5 = load i32* %k, align 4 %6 = load i32* %3, align 4 %7 = icmp slt i32 %5, %6 br i1 %7, label %8, label %28 ; <label>:8 ; preds = %4 %9 = load i32* %k, align 4 %10 = sub nsw i32 %9, 1 %11 = sext i32 %10 to i64 %12 = load double** %1, align 8 %13 = getelementptr inbounds double* %12, i64 %11 %14 = load double* %13, align 8 %15 = load i32* %k, align 4 %16 = sext i32 %15 to i64 %17 = load double** %2, align 8 %18 = getelementptr inbounds double* %17, i64 %16 %19 = load double* %18, align 8 %20 = fadd double %14, %19 %21 = load i32* %k, align 4 %22 = sext i32 %21 to i64 %23 = load double** %1, align 8 %24 = getelementptr inbounds double* %23, i64 %22 store double %20, double* %24, align 8 br label %25 ; <label>:25 ; preds = %8 %26 = load i32* %k, align 4 %27 = add nsw i32 %26, 1 store i32 %27, i32* %k, align 4 br label %4 ; <label>:28 ; preds = %4 ret i32 0 } ; We don't vectorize this function because A[i*7] is scalarized, and the ; different scalars can in theory wrap around and overwrite other scalar ; elements. At the moment we only allow read/write access to arrays ; that are consecutive. ; ; void foo(int *a) { ; for (int i=0; i<256; ++i) { ; int x = a[i*7]; ; if (x>3) ; x = x*x+x*4; ; a[i*7] = x+3; ; } ; } ; CHECK-LABEL: @func2( ; CHECK-NOT: <4 x i32> ; CHECK: ret define i32 @func2(i32* nocapture %a) nounwind uwtable ssp { br label %1 ; <label>:1 ; preds = %7, %0 %indvars.iv = phi i64 [ 0, %0 ], [ %indvars.iv.next, %7 ] %2 = mul nsw i64 %indvars.iv, 7 %3 = getelementptr inbounds i32* %a, i64 %2 %4 = load i32* %3, align 4 %5 = icmp sgt i32 %4, 3 br i1 %5, label %6, label %7 ; <label>:6 ; preds = %1 %tmp = add i32 %4, 4 %tmp1 = mul i32 %tmp, %4 br label %7 ; <label>:7 ; preds = %6, %1 %x.0 = phi i32 [ %tmp1, %6 ], [ %4, %1 ] %8 = add nsw i32 %x.0, 3 store i32 %8, i32* %3, align 4 %indvars.iv.next = add i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, 256 br i1 %exitcond, label %9, label %1 ; <label>:9 ; preds = %7 ret i32 0 }