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1; RUN: opt < %s -passes=loop-unroll -unroll-runtime -unroll-allow-partial -S | FileCheck %s2 3declare void @f() convergent4 5; Although this loop contains a convergent instruction, it should be6; fully unrolled.7;8; CHECK-LABEL: @full_unroll(9define i32 @full_unroll() {10entry:11 br label %l312 13l3:14 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]15; CHECK: call void @f()16; CHECK: call void @f()17; CHECK: call void @f()18; CHECK-NOT: call void @f()19 call void @f() ;convergent20 %inc = add nsw i32 %x.0, 121 %exitcond = icmp eq i32 %inc, 322 br i1 %exitcond, label %exit, label %l323 24exit:25 ret i32 026}27 28; This loop contains a convergent instruction, but it should be partially29; unrolled. The unroll count is the largest power of 2 that divides the30; multiple -- 4, in this case.31;32; CHECK-LABEL: @runtime_unroll(33define i32 @runtime_unroll(i32 %n) {34entry:35 %loop_ctl = mul nsw i32 %n, 1236 br label %l337 38l3:39 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]40; CHECK: call void @f()41; CHECK: call void @f()42; CHECK: call void @f()43; CHECK: call void @f()44; CHECK-NOT: call void @f()45 call void @f() convergent46 %inc = add nsw i32 %x.0, 147 %exitcond = icmp eq i32 %inc, %loop_ctl48 br i1 %exitcond, label %exit, label %l349 50exit:51 ret i32 052}53 54; This loop contains a convergent instruction, so its partial unroll55; count must divide its trip multiple. This overrides its unroll56; pragma -- we unroll exactly 8 times, even though 16 is requested.57; CHECK-LABEL: @pragma_unroll58define i32 @pragma_unroll(i32 %n) {59entry:60 %loop_ctl = mul nsw i32 %n, 2461 br label %l3, !llvm.loop !062 63l3:64 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]65; CHECK: call void @f()66; CHECK: call void @f()67; CHECK: call void @f()68; CHECK: call void @f()69; CHECK: call void @f()70; CHECK: call void @f()71; CHECK: call void @f()72; CHECK: call void @f()73; CHECK-NOT: call void @f()74 call void @f() convergent75 %inc = add nsw i32 %x.0, 176 %exitcond = icmp eq i32 %inc, %loop_ctl77 br i1 %exitcond, label %exit, label %l3, !llvm.loop !078 79exit:80 ret i32 081}82 83; This loop contains a convergent instruction. Since the pragma loop unroll84; count 2 divides trip count 4. The loop unroll should respect the pragma.85; CHECK-LABEL: @pragma_unroll_divisible_trip_count86define void @pragma_unroll_divisible_trip_count() {87entry:88 br label %l3, !llvm.loop !189 90l3:91 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]92; CHECK: call void @f()93; CHECK: call void @f()94; CHECK-NOT: call void @f()95 call void @f() convergent96 %inc = add nsw i32 %x.0, 197 %exitcond = icmp eq i32 %inc, 498 br i1 %exitcond, label %exit, label %l3, !llvm.loop !199 100exit:101 ret void102}103 104; This loop contains a convergent instruction. Since the pragma loop unroll105; count 2 divides trip multiple 2. The loop unroll should respect the pragma.106; CHECK-LABEL: @pragma_unroll_divisible_trip_multiple107define i32 @pragma_unroll_divisible_trip_multiple(i32 %n) {108entry:109 %loop_ctl = mul nsw i32 %n, 2110 br label %l3, !llvm.loop !1111 112l3:113 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]114; CHECK: call void @f()115; CHECK: call void @f()116; CHECK-NOT: call void @f()117 call void @f() convergent118 %inc = add nsw i32 %x.0, 1119 %exitcond = icmp eq i32 %inc, %loop_ctl120 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1121 122exit:123 ret i32 0124}125 126; This loop contains a convergent instruction. Since the pragma loop unroll127; count 2 is unknown to divide runtime trip count, the loop is not unrolled128; since remainder is forbidden for unrolling convergent loop.129; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed130; in the future.131; CHECK-LABEL: @pragma_unroll_indivisible_runtime_trip_count132define i32 @pragma_unroll_indivisible_runtime_trip_count(i32 %n) {133entry:134 br label %l3, !llvm.loop !1135 136l3:137 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]138; CHECK: call void @f()139; CHECK-NOT: call void @f()140 call void @f() convergent141 %inc = add nsw i32 %x.0, 1142 %exitcond = icmp eq i32 %inc, %n143 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1144 145exit:146 ret i32 0147}148 149; This loop contains a convergent instruction. Since the pragma loop unroll150; count 2 does not divide trip count 5, the loop is not unrolled by 2151; since remainder is forbidden for unrolling convergent loop. Instead, the152; loop gets fully unrolled.153; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed154; in the future.155; CHECK-LABEL: @pragma_unroll_indivisible_trip_count156define i32 @pragma_unroll_indivisible_trip_count() {157entry:158 br label %l3, !llvm.loop !1159 160l3:161 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ]162; CHECK: call void @f()163; CHECK: call void @f()164; CHECK: call void @f()165; CHECK: call void @f()166; CHECK: call void @f()167; CHECK-NOT: call void @f()168 call void @f() convergent169 %inc = add nsw i32 %x.0, 1170 %exitcond = icmp eq i32 %inc, 5171 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1172 173exit:174 ret i32 0175}176 177!0 = !{!0, !{!"llvm.loop.unroll.count", i32 16}}178!1 = !{!1, !{!"llvm.loop.unroll.count", i32 2}}179 180