Add -unroll-allow-partial command line option that enabled the loop unroller to

partially unroll a loop when fully unrolling would not fit under the threshold.

Patch by Mikael Lepistö.

llvm-svn: 54160

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopUnroll/partial.ll b/llvm/test/Transforms/LoopUnroll/partial.ll
new file mode 100644
index 00000000000..26da82b3b2b
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/partial.ll
@@ -0,0 +1,15 @@
+; RUN: llvm-as < %s | opt -debug -loop-unroll |& grep {will not try to unroll partially because}
+; RUN: llvm-as < %s | opt -debug -loop-unroll -unroll-allow-partial |& grep {partially unrolling with count}
+; RUN: llvm-as < %s | opt -debug -loop-unroll -unroll-allow-partial -unroll-threshold=3 |& grep {could not unroll partially}
+
+define i32 @main() {
+entry:
+	br label %no_exit
+no_exit:		; preds = %no_exit, %entry
+	%indvar = phi i32 [ 0, %entry ], [ %indvar.next, %no_exit ]		; <i32> [#uses=1]
+	%indvar.next = add i32 %indvar, 1		; <i32> [#uses=2]
+	%exitcond = icmp ne i32 %indvar.next, 100	; <i1> [#uses=1]
+	br i1 %exitcond, label %no_exit, label %loopexit
+loopexit:		; preds = %no_exit
+	ret i32 0
+}