Some more tests for the global structure vectorizer

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175964 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 596 insertions, 20 deletions

diff --git a/test/Transforms/LoopVectorize/global_alias.ll b/test/Transforms/LoopVectorize/global_alias.ll
index 84499de..24e698b 100644
--- a/test/Transforms/LoopVectorize/global_alias.ll
+++ b/test/Transforms/LoopVectorize/global_alias.ll
@@ -3,11 +3,19 @@
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:64:128-a0:0:64-n32-S64"
 
 %struct.anon = type { [100 x i32], i32, [100 x i32] }
+%struct.anon.0 = type { [100 x [100 x i32]], i32, [100 x [100 x i32]] }
 
 @Foo = common global %struct.anon zeroinitializer, align 4
+@Bar = common global %struct.anon.0 zeroinitializer, align 4
+
 @PB = external global i32*
 @PA = external global i32*
 
+
+;; === First, the tests that should always vectorize, wither statically or by adding run-time checks ===
+
+
+; /// Different objects, positive induction, constant distance
 ; int noAlias01 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)
@@ -55,6 +63,7 @@ for.end:                                          ; preds = %for.cond
   ret i32 %7
 }
 
+; /// Different objects, positive induction with widening slide
 ; int noAlias02 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE-10; i++)
@@ -103,6 +112,7 @@ for.end:                                          ; preds = %for.cond
   ret i32 %7
 }
 
+; /// Different objects, positive induction with shortening slide
 ; int noAlias03 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)
@@ -151,17 +161,185 @@ for.end:                                          ; preds = %for.cond
   ret i32 %7
 }
 
-; int mayAlias01 (int a) {
+; /// Pointer access, positive stride, run-time check added
+; int noAlias04 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)
-;     Foo.A[i] = Foo.B[SIZE-i-1] + a;
-;   return Foo.A[a];
+;     *(PA+i) = *(PB+i) + a;
+;   return *(PA+a);
 ; }
-; CHECK: define i32 @mayAlias01
+; CHECK: define i32 @noAlias04
 ; CHECK-NOT: add nsw <4 x i32>
 ; CHECK ret
+;
+; TODO: This test vectorizes (with run-time check) on real targets with -O3)
+; Check why it's not being vectorized even when forcing vectorization
 
-define i32 @mayAlias01(i32 %a) nounwind {
+define i32 @noAlias04(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32** @PB, align 4
+  %2 = load i32* %i, align 4
+  %add.ptr = getelementptr inbounds i32* %1, i32 %2
+  %3 = load i32* %add.ptr, align 4
+  %4 = load i32* %a.addr, align 4
+  %add = add nsw i32 %3, %4
+  %5 = load i32** @PA, align 4
+  %6 = load i32* %i, align 4
+  %add.ptr1 = getelementptr inbounds i32* %5, i32 %6
+  store i32 %add, i32* %add.ptr1, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %7 = load i32* %i, align 4
+  %inc = add nsw i32 %7, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %8 = load i32** @PA, align 4
+  %9 = load i32* %a.addr, align 4
+  %add.ptr2 = getelementptr inbounds i32* %8, i32 %9
+  %10 = load i32* %add.ptr2, align 4
+  ret i32 %10
+}
+
+; /// Different objects, positive induction, multi-array
+; int noAlias05 (int a) {
+;   int i, N=10;
+;   for (i=0; i<SIZE; i++)
+;     Bar.A[N][i] = Bar.B[N][i] + a;
+;   return Bar.A[N][a];
+; }
+; CHECK: define i32 @noAlias05
+; CHECK: add nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias05(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  %N = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 10, i32* %N, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %2 = load i32* %N, align 4
+  %arrayidx = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 2), i32 0, i32 %2
+  %arrayidx1 = getelementptr inbounds [100 x i32]* %arrayidx, i32 0, i32 %1
+  %3 = load i32* %arrayidx1, align 4
+  %4 = load i32* %a.addr, align 4
+  %add = add nsw i32 %3, %4
+  %5 = load i32* %i, align 4
+  %6 = load i32* %N, align 4
+  %arrayidx2 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %6
+  %arrayidx3 = getelementptr inbounds [100 x i32]* %arrayidx2, i32 0, i32 %5
+  store i32 %add, i32* %arrayidx3, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %7 = load i32* %i, align 4
+  %inc = add nsw i32 %7, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %8 = load i32* %a.addr, align 4
+  %9 = load i32* %N, align 4
+  %arrayidx4 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %9
+  %arrayidx5 = getelementptr inbounds [100 x i32]* %arrayidx4, i32 0, i32 %8
+  %10 = load i32* %arrayidx5, align 4
+  ret i32 %10
+}
+
+; /// Same objects, positive induction, multi-array, different sub-elements
+; int noAlias06 (int a) {
+;   int i, N=10;
+;   for (i=0; i<SIZE; i++)
+;     Bar.A[N][i] = Bar.A[N+1][i] + a;
+;   return Bar.A[N][a];
+; }
+; CHECK: define i32 @noAlias06
+; CHECK: add nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias06(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  %N = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 10, i32* %N, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %2 = load i32* %N, align 4
+  %add = add nsw i32 %2, 1
+  %arrayidx = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %add
+  %arrayidx1 = getelementptr inbounds [100 x i32]* %arrayidx, i32 0, i32 %1
+  %3 = load i32* %arrayidx1, align 4
+  %4 = load i32* %a.addr, align 4
+  %add2 = add nsw i32 %3, %4
+  %5 = load i32* %i, align 4
+  %6 = load i32* %N, align 4
+  %arrayidx3 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %6
+  %arrayidx4 = getelementptr inbounds [100 x i32]* %arrayidx3, i32 0, i32 %5
+  store i32 %add2, i32* %arrayidx4, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %7 = load i32* %i, align 4
+  %inc = add nsw i32 %7, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %8 = load i32* %a.addr, align 4
+  %9 = load i32* %N, align 4
+  %arrayidx5 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %9
+  %arrayidx6 = getelementptr inbounds [100 x i32]* %arrayidx5, i32 0, i32 %8
+  %10 = load i32* %arrayidx6, align 4
+  ret i32 %10
+}
+
+; /// Different objects, negative induction, constant distance
+; int noAlias07 (int a) {
+;   int i;
+;   for (i=0; i<SIZE; i++)
+;     Foo.A[SIZE-i-1] = Foo.B[SIZE-i-1] + a;
+;   return Foo.A[a];
+; }
+; CHECK: define i32 @noAlias07
+; CHECK: sub nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias07(i32 %a) #0 {
 entry:
   %a.addr = alloca i32, align 4
   %i = alloca i32, align 4
@@ -183,8 +361,10 @@ for.body:                                         ; preds = %for.cond
   %3 = load i32* %a.addr, align 4
   %add = add nsw i32 %2, %3
   %4 = load i32* %i, align 4
-  %arrayidx2 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %4
-  store i32 %add, i32* %arrayidx2, align 4
+  %sub2 = sub nsw i32 100, %4
+  %sub3 = sub nsw i32 %sub2, 1
+  %arrayidx4 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %sub3
+  store i32 %add, i32* %arrayidx4, align 4
   br label %for.inc
 
 for.inc:                                          ; preds = %for.body
@@ -195,22 +375,130 @@ for.inc:                                          ; preds = %for.body
 
 for.end:                                          ; preds = %for.cond
   %6 = load i32* %a.addr, align 4
-  %arrayidx3 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
-  %7 = load i32* %arrayidx3, align 4
+  %arrayidx5 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
+  %7 = load i32* %arrayidx5, align 4
+  ret i32 %7
+}
+
+; /// Different objects, negative induction, shortening slide
+; int noAlias08 (int a) {
+;   int i;
+;   for (i=0; i<SIZE-10; i++)
+;     Foo.A[SIZE-i-1] = Foo.B[SIZE-i-10] + a;
+;   return Foo.A[a];
+; }
+; CHECK: define i32 @noAlias08
+; CHECK: sub nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias08(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 90
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %sub = sub nsw i32 100, %1
+  %sub1 = sub nsw i32 %sub, 10
+  %arrayidx = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 2), i32 0, i32 %sub1
+  %2 = load i32* %arrayidx, align 4
+  %3 = load i32* %a.addr, align 4
+  %add = add nsw i32 %2, %3
+  %4 = load i32* %i, align 4
+  %sub2 = sub nsw i32 100, %4
+  %sub3 = sub nsw i32 %sub2, 1
+  %arrayidx4 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %sub3
+  store i32 %add, i32* %arrayidx4, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %5 = load i32* %i, align 4
+  %inc = add nsw i32 %5, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %6 = load i32* %a.addr, align 4
+  %arrayidx5 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
+  %7 = load i32* %arrayidx5, align 4
   ret i32 %7
 }
 
-; int mayAlias04 (int a) {
+; /// Different objects, negative induction, widening slide
+; int noAlias09 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)
-;     *(PA+i) = *(PB+i) + a;
+;     Foo.A[SIZE-i-10] = Foo.B[SIZE-i-1] + a;
 ;   return Foo.A[a];
 ; }
-; CHECK: define i32 @mayAlias04
-; CHECK-NOT: add nsw <4 x i32>
+; CHECK: define i32 @noAlias09
+; CHECK: sub nsw <4 x i32>
 ; CHECK ret
 
-define i32 @mayAlias04(i32 %a) {
+define i32 @noAlias09(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %sub = sub nsw i32 100, %1
+  %sub1 = sub nsw i32 %sub, 1
+  %arrayidx = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 2), i32 0, i32 %sub1
+  %2 = load i32* %arrayidx, align 4
+  %3 = load i32* %a.addr, align 4
+  %add = add nsw i32 %2, %3
+  %4 = load i32* %i, align 4
+  %sub2 = sub nsw i32 100, %4
+  %sub3 = sub nsw i32 %sub2, 10
+  %arrayidx4 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %sub3
+  store i32 %add, i32* %arrayidx4, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %5 = load i32* %i, align 4
+  %inc = add nsw i32 %5, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %6 = load i32* %a.addr, align 4
+  %arrayidx5 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
+  %7 = load i32* %arrayidx5, align 4
+  ret i32 %7
+}
+
+; /// Pointer access, negative stride, run-time check added
+; int noAlias10 (int a) {
+;   int i;
+;   for (i=0; i<SIZE; i++)
+;     *(PA+SIZE-i-1) = *(PB+SIZE-i-1) + a;
+;   return *(PA+a);
+; }
+; CHECK: define i32 @noAlias10
+; CHECK-NOT: sub nsw <4 x i32>
+; CHECK ret
+;
+; TODO: This test vectorizes (with run-time check) on real targets with -O3)
+; Check why it's not being vectorized even when forcing vectorization
+
+define i32 @noAlias10(i32 %a) #0 {
 entry:
   %a.addr = alloca i32, align 4
   %i = alloca i32, align 4
@@ -225,15 +513,21 @@ for.cond:                                         ; preds = %for.inc, %entry
 
 for.body:                                         ; preds = %for.cond
   %1 = load i32** @PB, align 4
+  %add.ptr = getelementptr inbounds i32* %1, i32 100
   %2 = load i32* %i, align 4
-  %add.ptr = getelementptr inbounds i32* %1, i32 %2
-  %3 = load i32* %add.ptr, align 4
+  %idx.neg = sub i32 0, %2
+  %add.ptr1 = getelementptr inbounds i32* %add.ptr, i32 %idx.neg
+  %add.ptr2 = getelementptr inbounds i32* %add.ptr1, i32 -1
+  %3 = load i32* %add.ptr2, align 4
   %4 = load i32* %a.addr, align 4
   %add = add nsw i32 %3, %4
   %5 = load i32** @PA, align 4
+  %add.ptr3 = getelementptr inbounds i32* %5, i32 100
   %6 = load i32* %i, align 4
-  %add.ptr1 = getelementptr inbounds i32* %5, i32 %6
-  store i32 %add, i32* %add.ptr1, align 4
+  %idx.neg4 = sub i32 0, %6
+  %add.ptr5 = getelementptr inbounds i32* %add.ptr3, i32 %idx.neg4
+  %add.ptr6 = getelementptr inbounds i32* %add.ptr5, i32 -1
+  store i32 %add, i32* %add.ptr6, align 4
   br label %for.inc
 
 for.inc:                                          ; preds = %for.body
@@ -245,11 +539,288 @@ for.inc:                                          ; preds = %for.body
 for.end:                                          ; preds = %for.cond
   %8 = load i32** @PA, align 4
   %9 = load i32* %a.addr, align 4
-  %add.ptr2 = getelementptr inbounds i32* %8, i32 %9
-  %10 = load i32* %add.ptr2, align 4
+  %add.ptr7 = getelementptr inbounds i32* %8, i32 %9
+  %10 = load i32* %add.ptr7, align 4
+  ret i32 %10
+}
+
+; /// Different objects, negative induction, multi-array
+; int noAlias11 (int a) {
+;   int i, N=10;
+;   for (i=0; i<SIZE; i++)
+;     Bar.A[N][SIZE-i-1] = Bar.B[N][SIZE-i-1] + a;
+;   return Bar.A[N][a];
+; }
+; CHECK: define i32 @noAlias11
+; CHECK: sub nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias11(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  %N = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 10, i32* %N, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %sub = sub nsw i32 100, %1
+  %sub1 = sub nsw i32 %sub, 1
+  %2 = load i32* %N, align 4
+  %arrayidx = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 2), i32 0, i32 %2
+  %arrayidx2 = getelementptr inbounds [100 x i32]* %arrayidx, i32 0, i32 %sub1
+  %3 = load i32* %arrayidx2, align 4
+  %4 = load i32* %a.addr, align 4
+  %add = add nsw i32 %3, %4
+  %5 = load i32* %i, align 4
+  %sub3 = sub nsw i32 100, %5
+  %sub4 = sub nsw i32 %sub3, 1
+  %6 = load i32* %N, align 4
+  %arrayidx5 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %6
+  %arrayidx6 = getelementptr inbounds [100 x i32]* %arrayidx5, i32 0, i32 %sub4
+  store i32 %add, i32* %arrayidx6, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %7 = load i32* %i, align 4
+  %inc = add nsw i32 %7, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %8 = load i32* %a.addr, align 4
+  %9 = load i32* %N, align 4
+  %arrayidx7 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %9
+  %arrayidx8 = getelementptr inbounds [100 x i32]* %arrayidx7, i32 0, i32 %8
+  %10 = load i32* %arrayidx8, align 4
+  ret i32 %10
+}
+
+; /// Same objects, negative induction, multi-array, different sub-elements
+; int noAlias12 (int a) {
+;   int i, N=10;
+;   for (i=0; i<SIZE; i++)
+;     Bar.A[N][SIZE-i-1] = Bar.A[N+1][SIZE-i-1] + a;
+;   return Bar.A[N][a];
+; }
+; CHECK: define i32 @noAlias12
+; CHECK: sub nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias12(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  %N = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 10, i32* %N, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %sub = sub nsw i32 100, %1
+  %sub1 = sub nsw i32 %sub, 1
+  %2 = load i32* %N, align 4
+  %add = add nsw i32 %2, 1
+  %arrayidx = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %add
+  %arrayidx2 = getelementptr inbounds [100 x i32]* %arrayidx, i32 0, i32 %sub1
+  %3 = load i32* %arrayidx2, align 4
+  %4 = load i32* %a.addr, align 4
+  %add3 = add nsw i32 %3, %4
+  %5 = load i32* %i, align 4
+  %sub4 = sub nsw i32 100, %5
+  %sub5 = sub nsw i32 %sub4, 1
+  %6 = load i32* %N, align 4
+  %arrayidx6 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %6
+  %arrayidx7 = getelementptr inbounds [100 x i32]* %arrayidx6, i32 0, i32 %sub5
+  store i32 %add3, i32* %arrayidx7, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %7 = load i32* %i, align 4
+  %inc = add nsw i32 %7, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %8 = load i32* %a.addr, align 4
+  %9 = load i32* %N, align 4
+  %arrayidx8 = getelementptr inbounds [100 x [100 x i32]]* getelementptr inbounds (%struct.anon.0* @Bar, i32 0, i32 0), i32 0, i32 %9
+  %arrayidx9 = getelementptr inbounds [100 x i32]* %arrayidx8, i32 0, i32 %8
+  %10 = load i32* %arrayidx9, align 4
   ret i32 %10
 }
 
+; /// Same objects, positive induction, constant distance, just enough for vector size
+; int noAlias13 (int a) {
+;   int i;
+;   for (i=0; i<SIZE; i++)
+;     Foo.A[i] = Foo.A[i+4] + a;
+;   return Foo.A[a];
+; }
+; CHECK: define i32 @noAlias13
+; CHECK: add nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias13(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %add = add nsw i32 %1, 4
+  %arrayidx = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %add
+  %2 = load i32* %arrayidx, align 4
+  %3 = load i32* %a.addr, align 4
+  %add1 = add nsw i32 %2, %3
+  %4 = load i32* %i, align 4
+  %arrayidx2 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %4
+  store i32 %add1, i32* %arrayidx2, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %5 = load i32* %i, align 4
+  %inc = add nsw i32 %5, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %6 = load i32* %a.addr, align 4
+  %arrayidx3 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
+  %7 = load i32* %arrayidx3, align 4
+  ret i32 %7
+}
+
+; /// Same objects, negative induction, constant distance, just enough for vector size
+; int noAlias14 (int a) {
+;   int i;
+;   for (i=0; i<SIZE; i++)
+;     Foo.A[SIZE-i-1] = Foo.A[SIZE-i-5] + a;
+;   return Foo.A[a];
+; }
+; CHECK: define i32 @noAlias14
+; CHECK: sub nsw <4 x i32>
+; CHECK ret
+
+define i32 @noAlias14(i32 %a) #0 {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %sub = sub nsw i32 100, %1
+  %sub1 = sub nsw i32 %sub, 5
+  %arrayidx = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %sub1
+  %2 = load i32* %arrayidx, align 4
+  %3 = load i32* %a.addr, align 4
+  %add = add nsw i32 %2, %3
+  %4 = load i32* %i, align 4
+  %sub2 = sub nsw i32 100, %4
+  %sub3 = sub nsw i32 %sub2, 1
+  %arrayidx4 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %sub3
+  store i32 %add, i32* %arrayidx4, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %5 = load i32* %i, align 4
+  %inc = add nsw i32 %5, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %6 = load i32* %a.addr, align 4
+  %arrayidx5 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
+  %7 = load i32* %arrayidx5, align 4
+  ret i32 %7
+}
+
+
+;; === Now, the tests that we could vectorize with induction changes or run-time checks ===
+
+
+; /// Different objects, swapped induction, alias at the end
+; int mayAlias01 (int a) {
+;   int i;
+;   for (i=0; i<SIZE; i++)
+;     Foo.A[i] = Foo.B[SIZE-i-1] + a;
+;   return Foo.A[a];
+; }
+; CHECK: define i32 @mayAlias01
+; CHECK-NOT: add nsw <4 x i32>
+; CHECK ret
+
+define i32 @mayAlias01(i32 %a) nounwind {
+entry:
+  %a.addr = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  store i32 0, i32* %i, align 4
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %0 = load i32* %i, align 4
+  %cmp = icmp slt i32 %0, 100
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %1 = load i32* %i, align 4
+  %sub = sub nsw i32 100, %1
+  %sub1 = sub nsw i32 %sub, 1
+  %arrayidx = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 2), i32 0, i32 %sub1
+  %2 = load i32* %arrayidx, align 4
+  %3 = load i32* %a.addr, align 4
+  %add = add nsw i32 %2, %3
+  %4 = load i32* %i, align 4
+  %arrayidx2 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %4
+  store i32 %add, i32* %arrayidx2, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %5 = load i32* %i, align 4
+  %inc = add nsw i32 %5, 1
+  store i32 %inc, i32* %i, align 4
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  %6 = load i32* %a.addr, align 4
+  %arrayidx3 = getelementptr inbounds [100 x i32]* getelementptr inbounds (%struct.anon* @Foo, i32 0, i32 0), i32 0, i32 %6
+  %7 = load i32* %arrayidx3, align 4
+  ret i32 %7
+}
+
+; /// Different objects, swapped induction, alias at the beginning
 ; int mayAlias02 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)
@@ -299,6 +870,7 @@ for.end:                                          ; preds = %for.cond
   ret i32 %7
 }
 
+; /// Pointer access, run-time check added
 ; int mayAlias03 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)
@@ -352,6 +924,10 @@ for.end:                                          ; preds = %for.cond
   ret i32 %10
 }
 
+
+;; === Finally, the tests that should only vectorize with care (or if we ignore undefined behaviour at all) ===
+
+
 ; int mustAlias01 (int a) {
 ;   int i;
 ;   for (i=0; i<SIZE; i++)