unknown-dep.ll
1.72 KB
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; RUN: opt -basicaa -loop-load-elim -S < %s | FileCheck %s
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
; Give up in the presence of unknown deps. Here, the different strides result
; in unknown dependence:
;
; for (unsigned i = 0; i < 100; i++) {
; A[i+1] = B[i] + 2;
; A[2*i] = C[i] + 2;
; D[i] = A[i] + 2;
; }
define void @f(i32* noalias %A, i32* noalias %B, i32* noalias %C,
i32* noalias %D, i64 %N) {
entry:
; for.body.ph:
; CHECK-NOT: %load_initial =
br label %for.body
for.body: ; preds = %for.body, %entry
; CHECK-NOT: %store_forwarded =
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
%Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
%Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
%Didx = getelementptr inbounds i32, i32* %D, i64 %indvars.iv
%Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
%indvars.m2 = mul nuw nsw i64 %indvars.iv, 2
%A2idx = getelementptr inbounds i32, i32* %A, i64 %indvars.m2
%b = load i32, i32* %Bidx, align 4
%a_p1 = add i32 %b, 2
store i32 %a_p1, i32* %Aidx_next, align 4
%c = load i32, i32* %Cidx, align 4
%a_m2 = add i32 %c, 2
store i32 %a_m2, i32* %A2idx, align 4
%a = load i32, i32* %Aidx, align 4
; CHECK-NOT: %d = add i32 %store_forwarded, 2
; CHECK: %d = add i32 %a, 2
%d = add i32 %a, 2
store i32 %d, i32* %Didx, 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
}