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, 95 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopInterchange/interchange-no-deps.ll b/llvm/test/Transforms/LoopInterchange/interchange-no-deps.ll
new file mode 100644
index 00000000000..5423648ce14
--- /dev/null
+++ b/llvm/test/Transforms/LoopInterchange/interchange-no-deps.ll
@@ -0,0 +1,95 @@
+; REQUIRES: asserts
+; RUN: opt < %s -loop-interchange -simplifycfg -pass-remarks-output=%t \
+; RUN:     -pass-remarks=loop-interchange -pass-remarks-missed=loop-interchange -stats -S 2>&1 \
+; RUN:     | FileCheck -check-prefix=STATS %s
+; RUN: FileCheck -input-file %t %s
+
+
+; no_deps_interchange just accesses a single nested array and can be interchange.
+; CHECK:      Name:       Interchanged
+; CHECK-NEXT: Function:   no_deps_interchange
+define i32 @no_deps_interchange([1024 x i32]* nocapture %Arr) local_unnamed_addr #0 {
+entry:
+  br label %for1.header
+
+for1.header:                                         ; preds = %entry, %for1.inc
+  %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for1.inc ]
+  br label %for2
+
+for2:                                        ; preds = %for1.header, %for2
+  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next, %for2 ]
+  %arrayidx6 = getelementptr inbounds [1024 x i32], [1024 x i32]* %Arr, i64 %indvars.iv, i64 %indvars.iv19
+  store i32 0, i32* %arrayidx6, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp ne i64 %indvars.iv.next, 1024
+  br i1 %exitcond, label %for2, label %for1.inc
+
+for1.inc:
+  %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
+  %exitcond21 = icmp ne i64 %indvars.iv.next20, 1024
+  br i1 %exitcond21, label %for1.header, label %exit
+
+exit:                                 ; preds = %for1.inc
+  ret i32 0
+
+}
+
+; Only the inner loop induction variable is used for memory accesses.
+; Interchanging is not beneficial.
+; CHECK:      Name:       InterchangeNotProfitable
+; CHECK-NEXT: Function:   no_bad_order
+define i32 @no_bad_order(i32* %Arr) {
+entry:
+  br label %for1.header
+
+for1.header:                                         ; preds = %entry, %for1.inc
+  %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for1.inc ]
+  br label %for2
+
+for2:                                        ; preds = %for1.header, %for2
+  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next, %for2 ]
+  %arrayidx6 = getelementptr inbounds i32, i32* %Arr, i64 %indvars.iv
+  store i32 0, i32* %arrayidx6, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp ne i64 %indvars.iv.next, 1024
+  br i1 %exitcond, label %for2, label %for1.inc
+
+for1.inc:
+  %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
+  %exitcond21 = icmp ne i64 %indvars.iv.next20, 1024
+  br i1 %exitcond21, label %for1.header, label %exit
+
+exit:                                 ; preds = %for1.inc
+  ret i32 0
+}
+
+; No memory access using any induction variables, interchanging not beneficial.
+; CHECK:      Name:        InterchangeNotProfitable
+; CHECK-NEXT: Function:    no_mem_instrs
+define i32 @no_mem_instrs(i64* %ptr) {
+entry:
+  br label %for1.header
+
+for1.header:                                         ; preds = %entry, %for1.inc
+  %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for1.inc ]
+  br label %for2
+
+for2:                                        ; preds = %for1.header, %for2
+  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next, %for2 ]
+  store i64 %indvars.iv, i64* %ptr, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp ne i64 %indvars.iv.next, 1024
+  br i1 %exitcond, label %for2, label %for1.inc
+
+for1.inc:
+  %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
+  %exitcond21 = icmp ne i64 %indvars.iv.next20, 1024
+  br i1 %exitcond21, label %for1.header, label %exit
+
+exit:                                 ; preds = %for1.inc
+  ret i32 0
+}
+
+
+; Check stats, we interchanged 1 out of 3 loops.
+; STATS: 1 loop-interchange - Number of loops interchanged