1 files changed, 110 insertions, 0 deletions
diff --git a/test/Transforms/LoopVectorize/same-base-access.ll b/test/Transforms/LoopVectorize/same-base-access.ll
new file mode 100644
index 0000000..1573893
--- /dev/null
+++ b/test/Transforms/LoopVectorize/same-base-access.ll
@@ -0,0 +1,110 @@
+; 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: @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: @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
+}