| ; RUN: opt -passes=loop-load-elim -S < %s | FileCheck %s |
| |
| ; In this case the later store forward to the load: |
| ; |
| ; for (unsigned i = 0; i < 100; i++) { |
| ; B[i] = A[i] + 1; |
| ; A[i+1] = C[i] + 2; |
| ; A[i+1] = D[i] + 3; |
| ; } |
| |
| target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" |
| |
| define void @f(ptr noalias nocapture %A, ptr noalias nocapture readonly %B, |
| ptr noalias nocapture %C, ptr noalias nocapture readonly %D, |
| i64 %N) { |
| entry: |
| ; CHECK: %load_initial = load i32, ptr %A |
| br label %for.body |
| |
| for.body: ; preds = %for.body, %entry |
| ; CHECK: %store_forwarded = phi i32 [ %load_initial, %entry ], [ %addD, %for.body ] |
| %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] |
| %arrayidxA = getelementptr inbounds i32, ptr %A, i64 %indvars.iv |
| %loadA = load i32, ptr %arrayidxA, align 4 |
| ; CHECK: %addA = add i32 %store_forwarded, 1 |
| %addA = add i32 %loadA, 1 |
| |
| %arrayidxB = getelementptr inbounds i32, ptr %B, i64 %indvars.iv |
| store i32 %addA, ptr %arrayidxB, align 4 |
| |
| %arrayidxC = getelementptr inbounds i32, ptr %C, i64 %indvars.iv |
| %loadC = load i32, ptr %arrayidxC, align 4 |
| %addC = add i32 %loadC, 2 |
| %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 |
| %arrayidxA_next = getelementptr inbounds i32, ptr %A, i64 %indvars.iv.next |
| store i32 %addC, ptr %arrayidxA_next, align 4 |
| |
| %arrayidxD = getelementptr inbounds i32, ptr %D, i64 %indvars.iv |
| %loadD = load i32, ptr %arrayidxD, align 4 |
| %addD = add i32 %loadD, 3 |
| store i32 %addD, ptr %arrayidxA_next, align 4 |
| |
| %exitcond = icmp eq i64 %indvars.iv.next, %N |
| br i1 %exitcond, label %for.end, label %for.body |
| |
| for.end: ; preds = %for.body |
| ret void |
| } |