; 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}}