1 ; RUN: opt < %s -loop-unroll -unroll-runtime -unroll-allow-partial -S | FileCheck %s 2 3 declare void @f() convergent 4 5 ; Although this loop contains a convergent instruction, it should be 6 ; fully unrolled. 7 ; 8 ; CHECK-LABEL: @full_unroll( 9 define i32 @full_unroll() { 10 entry: 11 br label %l3 12 13 l3: 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() ;convergent 20 %inc = add nsw i32 %x.0, 1 21 %exitcond = icmp eq i32 %inc, 3 22 br i1 %exitcond, label %exit, label %l3 23 24 exit: 25 ret i32 0 26 } 27 28 ; This loop contains a convergent instruction, but it should be partially 29 ; unrolled. The unroll count is the largest power of 2 that divides the 30 ; multiple -- 4, in this case. 31 ; 32 ; CHECK-LABEL: @runtime_unroll( 33 define i32 @runtime_unroll(i32 %n) { 34 entry: 35 %loop_ctl = mul nsw i32 %n, 12 36 br label %l3 37 38 l3: 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() convergent 46 %inc = add nsw i32 %x.0, 1 47 %exitcond = icmp eq i32 %inc, %loop_ctl 48 br i1 %exitcond, label %exit, label %l3 49 50 exit: 51 ret i32 0 52 } 53 54 ; This loop contains a convergent instruction, so its partial unroll 55 ; count must divide its trip multiple. This overrides its unroll 56 ; pragma -- we unroll exactly 8 times, even though 16 is requested. 57 ; CHECK-LABEL: @pragma_unroll 58 define i32 @pragma_unroll(i32 %n) { 59 entry: 60 %loop_ctl = mul nsw i32 %n, 24 61 br label %l3, !llvm.loop !0 62 63 l3: 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() convergent 75 %inc = add nsw i32 %x.0, 1 76 %exitcond = icmp eq i32 %inc, %loop_ctl 77 br i1 %exitcond, label %exit, label %l3, !llvm.loop !0 78 79 exit: 80 ret i32 0 81 } 82 83 ; This loop contains a convergent instruction. Since the pragma loop unroll 84 ; count 2 divides trip count 4. The loop unroll should respect the pragma. 85 ; CHECK-LABEL: @pragma_unroll_divisible_trip_count 86 define void @pragma_unroll_divisible_trip_count() { 87 entry: 88 br label %l3, !llvm.loop !1 89 90 l3: 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() convergent 96 %inc = add nsw i32 %x.0, 1 97 %exitcond = icmp eq i32 %inc, 4 98 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1 99 100 exit: 101 ret void 102 } 103 104 ; This loop contains a convergent instruction. Since the pragma loop unroll 105 ; count 2 divides trip multiple 2. The loop unroll should respect the pragma. 106 ; CHECK-LABEL: @pragma_unroll_divisible_trip_multiple 107 define i32 @pragma_unroll_divisible_trip_multiple(i32 %n) { 108 entry: 109 %loop_ctl = mul nsw i32 %n, 2 110 br label %l3, !llvm.loop !1 111 112 l3: 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() convergent 118 %inc = add nsw i32 %x.0, 1 119 %exitcond = icmp eq i32 %inc, %loop_ctl 120 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1 121 122 exit: 123 ret i32 0 124 } 125 126 ; This loop contains a convergent instruction. Since the pragma loop unroll 127 ; count 2 is unknown to divide runtime trip count, the loop is not unrolled 128 ; since remainder is forbidden for unrolling convergent loop. 129 ; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed 130 ; in the future. 131 ; CHECK-LABEL: @pragma_unroll_indivisible_runtime_trip_count 132 define i32 @pragma_unroll_indivisible_runtime_trip_count(i32 %n) { 133 entry: 134 br label %l3, !llvm.loop !1 135 136 l3: 137 %x.0 = phi i32 [ 0, %entry ], [ %inc, %l3 ] 138 ; CHECK: call void @f() 139 ; CHECK-NOT: call void @f() 140 call void @f() convergent 141 %inc = add nsw i32 %x.0, 1 142 %exitcond = icmp eq i32 %inc, %n 143 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1 144 145 exit: 146 ret i32 0 147 } 148 149 ; This loop contains a convergent instruction. Since the pragma loop unroll 150 ; count 2 does not divide trip count 5, the loop is not unrolled by 2 151 ; since remainder is forbidden for unrolling convergent loop. Instead, the 152 ; loop gets fully unrolled. 153 ; ToDo: Forbidding remainder for unrolling convergent loop may be relaxed 154 ; in the future. 155 ; CHECK-LABEL: @pragma_unroll_indivisible_trip_count 156 define i32 @pragma_unroll_indivisible_trip_count() { 157 entry: 158 br label %l3, !llvm.loop !1 159 160 l3: 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() convergent 169 %inc = add nsw i32 %x.0, 1 170 %exitcond = icmp eq i32 %inc, 5 171 br i1 %exitcond, label %exit, label %l3, !llvm.loop !1 172 173 exit: 174 ret i32 0 175 } 176 177 !0 = !{!0, !{!"llvm.loop.unroll.count", i32 16}} 178 !1 = !{!1, !{!"llvm.loop.unroll.count", i32 2}} 179 180
