; RUN: opt -S -unroll-runtime -loop-unroll < %s | FileCheck %s target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" ;; Check that we don't emit expensive instructions to compute trip ;; counts when unrolling loops. define i32 @test(i64 %v12, i8* %array, i64* %loc) { ; CHECK-LABEL: @test( ; CHECK-NOT: udiv entry: %step = load i64, i64* %loc, !range !0 br label %loop loop: ; preds = %entry, %loop %k.015 = phi i64 [ %v15, %loop ], [ %v12, %entry ] %v14 = getelementptr inbounds i8, i8* %array, i64 %k.015 store i8 0, i8* %v14 %v15 = add nuw nsw i64 %k.015, %step %v16 = icmp slt i64 %v15, 8193 br i1 %v16, label %loop, label %loopexit loopexit: ; preds = %loop ret i32 0 } ;; Though SCEV for loop tripcount contains division, ;; it shouldn't be considered expensive, since the division already ;; exists in the code and we don't need to expand it once more. ;; Thus, it shouldn't prevent us from unrolling the loop. define i32 @test2(i64* %loc, i64 %conv7) { ; CHECK-LABEL: @test2( ; CHECK: udiv ; CHECK: udiv ; CHECK-NOT: udiv ; CHECK-LABEL: for.body entry: %rem0 = load i64, i64* %loc, align 8 %ExpensiveComputation = udiv i64 %rem0, 42 ; <<< Extra computations are added to the trip-count expression br label %bb1 bb1: %div11 = udiv i64 %ExpensiveComputation, %conv7 %cmp.i38 = icmp ugt i64 %div11, 1 %div12 = select i1 %cmp.i38, i64 %div11, i64 1 br label %for.body for.body: %rem1 = phi i64 [ %rem0, %bb1 ], [ %rem2, %for.body ] %k1 = phi i64 [ %div12, %bb1 ], [ %dec, %for.body ] %mul1 = mul i64 %rem1, 48271 %rem2 = urem i64 %mul1, 2147483647 %dec = add i64 %k1, -1 %cmp = icmp eq i64 %dec, 0 br i1 %cmp, label %exit, label %for.body exit: %rem3 = phi i64 [ %rem2, %for.body ] store i64 %rem3, i64* %loc, align 8 ret i32 0 } !0 = !{i64 1, i64 100}