[LoopInterchange] Split up interchange.ll test case (NFC).

Summary:
Currently most tests for the loop interchange pass are in
test/Transforms/LoopInterchange/interchange.ll. This patch splits up the
large test file in smaller pieces, which makes debugging test failures
easier.

Reviewers: karthikthecool, blitz.opensource, hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, mcrosier, mkuper, mzolotukhin, mssimpso, llvm-commits

Differential Revision: https://reviews.llvm.org/D35488

llvm-svn: 308284
diff --git a/llvm/test/Transforms/LoopInterchange/interchange-simple-count-down.ll b/llvm/test/Transforms/LoopInterchange/interchange-simple-count-down.ll
new file mode 100644
index 0000000..70ba594
--- /dev/null
+++ b/llvm/test/Transforms/LoopInterchange/interchange-simple-count-down.ll
@@ -0,0 +1,69 @@
+; RUN: opt < %s -basicaa -loop-interchange -S | FileCheck %s
+;; We test the complete .ll for adjustment in outer loop header/latch and inner loop header/latch.
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@A = common global [100 x [100 x i32]] zeroinitializer
+@B = common global [100 x i32] zeroinitializer
+
+;; for(int i=0;i<100;i++)
+;;   for(int j=100;j>=0;j--)
+;;     A[j][i] = A[j][i]+k;
+
+define void @interchange_02(i32 %k) {
+entry:
+  br label %for.cond1.preheader
+
+for.cond1.preheader:
+  %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for.inc10 ]
+  br label %for.body3
+
+for.body3:
+  %indvars.iv = phi i64 [ 100, %for.cond1.preheader ], [ %indvars.iv.next, %for.body3 ]
+  %arrayidx5 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv19
+  %0 = load i32, i32* %arrayidx5
+  %add = add nsw i32 %0, %k
+  store i32 %add, i32* %arrayidx5
+  %indvars.iv.next = add nsw i64 %indvars.iv, -1
+  %cmp2 = icmp sgt i64 %indvars.iv, 0
+  br i1 %cmp2, label %for.body3, label %for.inc10
+
+for.inc10:
+  %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
+  %exitcond = icmp eq i64 %indvars.iv.next20, 100
+  br i1 %exitcond, label %for.end11, label %for.cond1.preheader
+
+for.end11:
+  ret void
+}
+
+; CHECK-LABEL: @interchange_02
+; CHECK: entry:
+; CHECK:   br label %for.body3.preheader
+; CHECK: for.cond1.preheader.preheader:
+; CHECK:   br label %for.cond1.preheader
+; CHECK: for.cond1.preheader:
+; CHECK:   %indvars.iv19 = phi i64 [ %indvars.iv.next20, %for.inc10 ], [ 0, %for.cond1.preheader.preheader ]
+; CHECK:   br label %for.body3.split1
+; CHECK: for.body3.preheader:
+; CHECK:   br label %for.body3
+; CHECK: for.body3:
+; CHECK:   %indvars.iv = phi i64 [ %indvars.iv.next, %for.body3.split ], [ 100, %for.body3.preheader ]
+; CHECK:   br label %for.cond1.preheader.preheader
+; CHECK: for.body3.split1:                                 ; preds = %for.cond1.preheader
+; CHECK:   %arrayidx5 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv19
+; CHECK:   %0 = load i32, i32* %arrayidx5
+; CHECK:   %add = add nsw i32 %0, %k
+; CHECK:   store i32 %add, i32* %arrayidx5
+; CHECK:   br label %for.inc10
+; CHECK: for.body3.split:
+; CHECK:   %indvars.iv.next = add nsw i64 %indvars.iv, -1
+; CHECK:   %cmp2 = icmp sgt i64 %indvars.iv, 0
+; CHECK:   br i1 %cmp2, label %for.body3, label %for.end11
+; CHECK: for.inc10:
+; CHECK:   %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
+; CHECK:   %exitcond = icmp eq i64 %indvars.iv.next20, 100
+; CHECK:   br i1 %exitcond, label %for.body3.split, label %for.cond1.preheader
+; CHECK: for.end11:
+; CHECK:   ret void