Revert "Temporarily Revert "Add basic loop fusion pass.""

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopUnroll/full-unroll-heuristics-geps.ll b/llvm/test/Transforms/LoopUnroll/full-unroll-heuristics-geps.ll
new file mode 100644
index 00000000000..238869d120b
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/full-unroll-heuristics-geps.ll
@@ -0,0 +1,29 @@
+; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=100 -unroll-threshold=10 -unroll-max-percent-threshold-boost=200 | FileCheck %s
+; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop(unroll-full)' -unroll-max-iteration-count-to-analyze=100 -unroll-threshold=10 -unroll-max-percent-threshold-boost=200 | FileCheck %s
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+; When examining gep-instructions we shouldn't consider them simplified if the
+; corresponding memory access isn't simplified. Doing the opposite might bias
+; our estimate, so that we might decide to unroll even a simple memcpy loop.
+;
+; Thus, the following loop shouldn't be unrolled:
+; CHECK-LABEL: @not_simplified_geps
+; CHECK: br i1 %
+; CHECK: ret void
+define void @not_simplified_geps(i32* noalias %b, i32* noalias %c) {
+entry:
+  br label %for.body
+
+for.body:
+  %iv.0 = phi i64 [ 0, %entry ], [ %iv.1, %for.body ]
+  %arrayidx1 = getelementptr inbounds i32, i32* %b, i64 %iv.0
+  %x1 = load i32, i32* %arrayidx1, align 4
+  %arrayidx2 = getelementptr inbounds i32, i32* %c, i64 %iv.0
+  store i32 %x1, i32* %arrayidx2, align 4
+  %iv.1 = add nuw nsw i64 %iv.0, 1
+  %exitcond = icmp eq i64 %iv.1, 10
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}