• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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
8target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
9
10define void @f(i32* noalias nocapture %A, i32* noalias nocapture readonly %B, i64 %N) {
11entry:
12; CHECK: %load_initial = load i32, i32* %A
13  br label %for.body
14
15for.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
30for.end:                                          ; preds = %for.body
31  ret void
32}
33