Check for side effects before splitting loop.

Patch by Jakub Staszak!

llvm-svn: 102928

2 files changed, 61 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopIndexSplit/PR4174-2.ll b/llvm/test/Transforms/LoopIndexSplit/PR4174-2.ll
new file mode 100644
index 00000000000..cc17bc0a933
--- /dev/null
+++ b/llvm/test/Transforms/LoopIndexSplit/PR4174-2.ll
@@ -0,0 +1,38 @@
+; RUN: llvm-as < %s | opt -loop-index-split | llvm-dis | not grep clone
+
+declare void @f()
+
+define fastcc i32 @main() nounwind {
+entry:
+        br label %bb1552
+
+bb1552:
+        %j295.0.reg2mem.0 = phi i32 [ %storemerge110, %bb1669 ], [ 0, %entry ]
+        br label %bb1553
+
+bb1553:
+        call void @f()
+        %tmp1628 = icmp sgt i32 %j295.0.reg2mem.0, -3
+        br i1 %tmp1628, label %bb1588, label %bb1616
+
+bb1588:
+        br label %bb1616
+
+bb1616:
+        %tmp1629 = icmp sgt i32 %j295.0.reg2mem.0, -3
+        br i1 %tmp1629, label %bb1649, label %bb1632
+
+bb1632:
+        br label %bb1669
+
+bb1649:
+        br label %bb1669
+
+bb1669:
+        %storemerge110 = add i32 %j295.0.reg2mem.0, 1
+        %tmp1672 = icmp sgt i32 %storemerge110, 3
+        br i1 %tmp1672, label %bb1678, label %bb1552
+
+bb1678:
+        ret i32 0
+}
diff --git a/llvm/test/Transforms/LoopIndexSplit/PR4174.ll b/llvm/test/Transforms/LoopIndexSplit/PR4174.ll
new file mode 100644
index 00000000000..e8f5a737f05
--- /dev/null
+++ b/llvm/test/Transforms/LoopIndexSplit/PR4174.ll
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | opt -loop-index-split | llvm-dis | not grep clone
+
+declare void @f()
+
+define i32 @main() {
+entry:
+        br label %head
+head:
+        %i = phi i32 [0, %entry], [%i1, %tail]
+        call void @f()
+        %splitcond = icmp slt i32 %i, 2
+        br i1 %splitcond, label %yes, label %no
+yes:
+        br label %tail
+no:
+        br label %tail
+tail:
+        %i1 = add i32 %i, 1
+        %exitcond = icmp slt i32 %i1, 4
+        br i1 %exitcond, label %head, label %exit
+exit:
+        ret i32 0
+}