1; RUN: opt -verify-loop-info -irce-print-changed-loops -irce -S < %s 2>&1 | FileCheck %s 2; RUN: opt -verify-loop-info -irce-print-changed-loops -passes='require<branch-prob>,irce' -S < %s 2>&1 | FileCheck %s 3 4; The test demonstrates that incorrect behavior of Clamp may lead to incorrect 5; calculation of post-loop exit condition. 6 7; CHECK-LABEL: irce: in function test_01: constrained Loop at depth 1 containing: %loop<header><exiting>,%in_bounds<exiting>,%not_zero<latch><exiting> 8; CHECK-NOT: irce: in function test_02: constrained Loop 9 10define void @test_01() { 11 12; CHECK-LABEL: test_01 13 14entry: 15 %indvars.iv.next467 = add nuw nsw i64 2, 1 16 %length.i167 = load i32, i32 addrspace(1)* undef, align 8 17 %tmp21 = zext i32 %length.i167 to i64 18 %tmp34 = load atomic i32, i32 addrspace(1)* undef unordered, align 4 19 %tmp35 = add i32 %tmp34, -9581 20 %tmp36 = icmp ugt i32 %length.i167, 1 21 br i1 %tmp36, label %preheader, label %exit 22 23exit: ; preds = %in_bounds, %loop, %not_zero, %entry 24 ret void 25 26preheader: ; preds = %entry 27; CHECK: preheader: 28; CHECK-NEXT: %length_gep.i146 = getelementptr inbounds i8, i8 addrspace(1)* undef, i64 8 29; CHECK-NEXT: %length_gep_typed.i147 = bitcast i8 addrspace(1)* undef to i32 addrspace(1)* 30; CHECK-NEXT: %tmp43 = icmp ult i64 %indvars.iv.next467, %tmp21 31; CHECK-NEXT: %exit.mainloop.at = call i64 @llvm.umax.i64(i64 %tmp21, i64 1) 32; CHECK-NEXT: [[C1:%[^ ]+]] = icmp ult i64 1, %exit.mainloop.at 33; CHECK-NEXT: br i1 [[C1]], label %loop.preheader, label %main.pseudo.exit 34 35 %length_gep.i146 = getelementptr inbounds i8, i8 addrspace(1)* undef, i64 8 36 %length_gep_typed.i147 = bitcast i8 addrspace(1)* undef to i32 addrspace(1)* 37 %tmp43 = icmp ult i64 %indvars.iv.next467, %tmp21 38 br label %loop 39 40not_zero: ; preds = %in_bounds 41; CHECK: not_zero: 42; CHECK: %tmp56 = icmp ult i64 %indvars.iv.next, %tmp21 43; CHECK-NEXT: [[COND:%[^ ]+]] = icmp ult i64 %indvars.iv.next, %exit.mainloop.at 44; CHECK-NEXT: br i1 [[COND]], label %loop, label %main.exit.selector 45 46 %tmp51 = trunc i64 %indvars.iv.next to i32 47 %tmp53 = mul i32 %tmp51, %tmp51 48 %tmp54 = add i32 %tmp53, -9582 49 %tmp55 = add i32 %tmp54, %tmp62 50 %tmp56 = icmp ult i64 %indvars.iv.next, %tmp21 51 br i1 %tmp56, label %loop, label %exit 52 53loop: ; preds = %not_zero, %preheader 54 %tmp62 = phi i32 [ 1, %preheader ], [ %tmp55, %not_zero ] 55 %indvars.iv750 = phi i64 [ 1, %preheader ], [ %indvars.iv.next, %not_zero ] 56 %length.i148 = load i32, i32 addrspace(1)* %length_gep_typed.i147, align 8 57 %tmp68 = zext i32 %length.i148 to i64 58 %tmp97 = icmp ult i64 2, %tmp68 59 %or.cond = and i1 %tmp43, %tmp97 60 %tmp99 = icmp ult i64 %indvars.iv750, %tmp21 61 %or.cond1 = and i1 %or.cond, %tmp99 62 br i1 %or.cond1, label %in_bounds, label %exit 63 64in_bounds: ; preds = %loop 65 %indvars.iv.next = add nuw nsw i64 %indvars.iv750, 3 66 %tmp107 = icmp ult i64 %indvars.iv.next, 2 67 br i1 %tmp107, label %not_zero, label %exit 68} 69 70define void @test_02() { 71 72; Now IRCE is smart enough to understand that the safe range here is empty. 73; Previously it executed the entire loop in safe preloop and never actually 74; entered the main loop. 75 76entry: 77 br label %loop 78 79loop: ; preds = %in_bounds, %entry 80 %iv1 = phi i64 [ 3, %entry ], [ %iv1.next, %in_bounds ] 81 %iv2 = phi i64 [ 4294967295, %entry ], [ %iv2.next, %in_bounds ] 82 %iv2.offset = add i64 %iv2, 1 83 %rc = icmp ult i64 %iv2.offset, 400 84 br i1 %rc, label %in_bounds, label %bci_321 85 86bci_321: ; preds = %in_bounds, %loop 87 ret void 88 89in_bounds: ; preds = %loop 90 %iv1.next = add nuw nsw i64 %iv1, 2 91 %iv2.next = add nuw nsw i64 %iv2, 2 92 %cond = icmp ugt i64 %iv1, 204 93 br i1 %cond, label %bci_321, label %loop 94} 95