1 ; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=100 -unroll-threshold=12 -unroll-max-percent-threshold-boost=400 | FileCheck %s 2 ; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop(unroll-full)' -unroll-max-iteration-count-to-analyze=100 -unroll-threshold=12 -unroll-max-percent-threshold-boost=400 | FileCheck %s 3 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" 4 5 @known_constant = internal unnamed_addr constant [10 x i32] [i32 0, i32 0, i32 0, i32 0, i32 1, i32 0, i32 0, i32 0, i32 0, i32 0], align 16 6 7 ; If a load becomes a constant after loop unrolling, we sometimes can simplify 8 ; CFG. This test verifies that we handle such cases. 9 ; After one operand in an instruction is constant-folded and the 10 ; instruction is simplified, the other operand might become dead. 11 ; In this test we have:: 12 ; for i in 1..10: 13 ; r += A[i] * B[i] 14 ; A[i] is 0 almost at every iteration, so there is no need in loading B[i] at 15 ; all. 16 17 18 ; CHECK-LABEL: @unroll_dce 19 ; CHECK-NOT: br i1 %exitcond, label %for.end, label %for.body 20 define i32 @unroll_dce(i32* noalias nocapture readonly %b) { 21 entry: 22 br label %for.body 23 24 for.body: ; preds = %for.body, %entry 25 %iv.0 = phi i64 [ 0, %entry ], [ %iv.1, %for.body ] 26 %r.0 = phi i32 [ 0, %entry ], [ %r.1, %for.body ] 27 %arrayidx1 = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv.0 28 %x1 = load i32, i32* %arrayidx1, align 4 29 %arrayidx2 = getelementptr inbounds i32, i32* %b, i64 %iv.0 30 %x2 = load i32, i32* %arrayidx2, align 4 31 %mul = mul i32 %x1, %x2 32 %r.1 = add i32 %mul, %r.0 33 %iv.1 = add nuw nsw i64 %iv.0, 1 34 %exitcond = icmp eq i64 %iv.1, 10 35 br i1 %exitcond, label %for.end, label %for.body 36 37 for.end: ; preds = %for.body 38 ret i32 %r.1 39 } 40
