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, 179 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopUnroll/convergent.ll b/llvm/test/Transforms/LoopUnroll/convergent.ll
new file mode 100644
index 00000000000..8417c370f84
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/convergent.ll
@@ -0,0 +1,179 @@
+; RUN: opt < %s -loop-unroll -unroll-runtime -unroll-allow-partial -S | FileCheck %s
+
+declare void @f() convergent
+
+; Although this loop contains a convergent instruction, it should be
+; fully unrolled.
+;
+; CHECK-LABEL: @full_unroll(
+define i32 @full_unroll() {
+entry:
+  br label %l3
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() ;convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, 3
+  br i1 %exitcond, label %exit, label %l3
+
+exit:
+  ret i32 0
+}
+
+; This loop contains a convergent instruction, but it should be partially
+; unrolled.  The unroll count is the largest power of 2 that divides the
+; multiple -- 4, in this case.
+;
+; CHECK-LABEL: @runtime_unroll(
+define i32 @runtime_unroll(i32 %n) {
+entry:
+  %loop_ctl = mul nsw i32 %n, 12
+  br label %l3
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, %loop_ctl
+  br i1 %exitcond, label %exit, label %l3
+
+exit:
+  ret i32 0
+}
+
+; This loop contains a convergent instruction, so its partial unroll
+; count must divide its trip multiple.  This overrides its unroll
+; pragma -- we unroll exactly 8 times, even though 16 is requested.
+; CHECK-LABEL: @pragma_unroll
+define i32 @pragma_unroll(i32 %n) {
+entry:
+  %loop_ctl = mul nsw i32 %n, 24
+  br label %l3, !llvm.loop !0
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, %loop_ctl
+  br i1 %exitcond, label %exit, label %l3, !llvm.loop !0
+
+exit:
+  ret i32 0
+}
+
+; This loop contains a convergent instruction. Since the pragma loop unroll
+; count 2 divides trip count 4. The loop unroll should respect the pragma.
+; CHECK-LABEL: @pragma_unroll_divisible_trip_count
+define void @pragma_unroll_divisible_trip_count() {
+entry:
+  br label %l3, !llvm.loop !1
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, 4
+  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
+
+exit:
+  ret void
+}
+
+; This loop contains a convergent instruction. Since the pragma loop unroll
+; count 2 divides trip multiple 2. The loop unroll should respect the pragma.
+; CHECK-LABEL: @pragma_unroll_divisible_trip_multiple
+define i32 @pragma_unroll_divisible_trip_multiple(i32 %n) {
+entry:
+  %loop_ctl = mul nsw i32 %n, 2
+  br label %l3, !llvm.loop !1
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, %loop_ctl
+  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
+
+exit:
+  ret i32 0
+}
+
+; This loop contains a convergent instruction. Since the pragma loop unroll
+; count 2 is unknown to divide runtime trip count, the loop is not unrolled
+; since remainder is forbidden for unrolling convergent loop.
+; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed
+; in the future.
+; CHECK-LABEL: @pragma_unroll_indivisible_runtime_trip_count
+define i32 @pragma_unroll_indivisible_runtime_trip_count(i32 %n) {
+entry:
+  br label %l3, !llvm.loop !1
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, %n
+  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
+
+exit:
+  ret i32 0
+}
+
+; This loop contains a convergent instruction. Since the pragma loop unroll
+; count 2 does not divide trip count 5, the loop is not unrolled by 2
+; since remainder is forbidden for unrolling convergent loop. Instead, the
+; loop gets fully unrolled.
+; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed
+; in the future.
+; CHECK-LABEL: @pragma_unroll_indivisible_trip_count
+define i32 @pragma_unroll_indivisible_trip_count() {
+entry:
+  br label %l3, !llvm.loop !1
+
+l3:
+  %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK: call void @f()
+; CHECK-NOT: call void @f()
+  call void @f() convergent
+  %inc = add nsw i32 %x.0, 1
+  %exitcond = icmp eq i32 %inc, 5
+  br i1 %exitcond, label %exit, label %l3, !llvm.loop !1
+
+exit:
+  ret i32 0
+}
+
+!0 = !{!0, !{!"llvm.loop.unroll.count", i32 16}}
+!1 = !{!1, !{!"llvm.loop.unroll.count", i32 2}}
+