1 ; RUN: opt -loop-load-elim -S < %s | FileCheck %s 2 3 ; Simple st->ld forwarding derived from a lexical backward dep. 4 ; 5 ; for (unsigned i = 0; i < 100; i++) 6 ; A[i+1] = A[i] + B[i]; 7 8 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" 9 10 define void @f(i32* noalias nocapture %A, i32* noalias nocapture readonly %B, i64 %N) { 11 entry: 12 ; CHECK: %load_initial = load i32, i32* %A 13 br label %for.body 14 15 for.body: ; preds = %for.body, %entry 16 ; CHECK: %store_forwarded = phi i32 [ %load_initial, %entry ], [ %add, %for.body ] 17 %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] 18 %arrayidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv 19 %load = load i32, i32* %arrayidx, align 4 20 %arrayidx2 = getelementptr inbounds i32, i32* %B, i64 %indvars.iv 21 %load_1 = load i32, i32* %arrayidx2, align 4 22 ; CHECK: %add = add i32 %load_1, %store_forwarded 23 %add = add i32 %load_1, %load 24 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 25 %arrayidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next 26 store i32 %add, i32* %arrayidx_next, align 4 27 %exitcond = icmp eq i64 %indvars.iv.next, %N 28 br i1 %exitcond, label %for.end, label %for.body 29 30 for.end: ; preds = %for.body 31 ret void 32 } 33
