Expand LDA testcases.

llvm-svn: 77926

llvm/test/Analysis/LoopDependenceAnalysis/siv-weak-crossing.ll

@@ -4,7 +4,7 @@
 @y = common global [256 x i32] zeroinitializer, align 4
 
 ;; for (i = 0; i < 256; i++)
-;;   x[i] = x[256 - i] + y[i]
+;;   x[i] = x[255 - i] + y[i]
 
 define void @f1(...) nounwind {
 entry:
@@ -12,8 +12,8 @@ entry:
 
 for.body:
   %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
-  %i.256 = sub i64 256, %i
-  %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i.256
+  %i.255 = sub i64 255, %i
+  %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i.255
   %x.ld.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i
   %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i
   %x = load i32* %x.ld.addr     ; 0
@@ -30,9 +30,8 @@ for.end:
   ret void
 }
 
-;; // the same example, using more realistic IR
-;; for (i = 0; i < 256; i++)
-;;   x[i] = x[256 - i] + y[i]
+;; for (i = 0; i < 100; i++)
+;;   x[i] = x[255 - i] + y[i]
 
 define void @f2(...) nounwind {
 entry:
@@ -40,9 +39,9 @@ entry:
 
 for.body:
   %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
-  %i.256 = sub i64 0, %i
+  %i.255 = sub i64 0, %i
   %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i
-  %x.ld.addr = getelementptr [256 x i32]* @x, i64 1, i64 %i.256
+  %x.ld.addr = getelementptr [256 x i32]* @x, i64 1, i64 %i.255
   %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i
   %x = load i32* %x.ld.addr     ; 0
   %y = load i32* %y.ld.addr     ; 1
@@ -51,14 +50,16 @@ for.body:
 ; CHECK: 0,2: dep
 ; CHECK: 1,2: ind
   %i.next = add i64 %i, 1
-  %exitcond = icmp eq i64 %i.next, 256
+  %exitcond = icmp eq i64 %i.next, 100
   br i1 %exitcond, label %for.end, label %for.body
 
 for.end:
   ret void
 }
 
-;; for (i = 0; i < 100; i++)
+;; // the first iteration (i=0) leads to an out-of-bounds access of x. as the
+;; // result of this access is undefined, _any_ dependence result is safe.
+;; for (i = 0; i < 256; i++)
 ;;   x[i] = x[256 - i] + y[i]
 
 define void @f3(...) nounwind {
@@ -76,9 +77,40 @@ for.body:
   %r = add i32 %y, %x
   store i32 %r, i32* %x.st.addr ; 2
 ; CHECK: 0,2: dep
-; CHECK: 1,2: ind
+; CHECK: 1,2:
   %i.next = add i64 %i, 1
-  %exitcond = icmp eq i64 %i.next, 100
+  %exitcond = icmp eq i64 %i.next, 256
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+;; // slightly contrived but valid IR for the following loop, where all
+;; // accesses in all iterations are within bounds. while this example's first
+;; // (ZIV-)subscript is (0, 1), accesses are dependent.
+;; for (i = 1; i < 256; i++)
+;;   x[i] = x[256 - i] + y[i]
+
+define void @f4(...) nounwind {
+entry:
+  br label %for.body
+
+for.body:
+  %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
+  %i.1 = add i64 1, %i
+  %i.256 = sub i64 -1, %i
+  %y.ld.addr = getelementptr [256 x i32]* @y, i64 0, i64 %i.1
+  %x.ld.addr = getelementptr [256 x i32]* @x, i64 1, i64 %i.256
+  %x.st.addr = getelementptr [256 x i32]* @x, i64 0, i64 %i.1
+  %x = load i32* %x.ld.addr     ; 0
+  %y = load i32* %y.ld.addr     ; 1
+  %r = add i32 %y, %x
+  store i32 %r, i32* %x.st.addr ; 2
+; CHECK: 0,2: dep
+; CHECK: 1,2: ind
+  %i.next = add i64 %i, 1
+  %exitcond = icmp eq i64 %i.next, 256
   br i1 %exitcond, label %for.end, label %for.body
 
 for.end:

llvm/test/Analysis/LoopDependenceAnalysis/ziv.ll

@@ -42,3 +42,22 @@ for.body:
 for.end:
   ret void
 }
+
+;; x[6] = x[6]
+
+define void @f3(...) nounwind {
+entry:
+  br label %for.body
+
+for.body:
+  %i = phi i64 [ 0, %entry ], [ %i.next, %for.body ]
+  %x = load i32* getelementptr ([256 x i32]* @x, i32 0, i64 6)
+  store i32 %x, i32* getelementptr ([256 x i32]* @x, i32 0, i64 6)
+; CHECK: 0,1: dep
+  %i.next = add i64 %i, 1
+  %exitcond = icmp eq i64 %i.next, 256
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}