34 lines
1.3 KiB
LLVM
34 lines
1.3 KiB
LLVM
; RUN: opt -loop-load-elim -S < %s | FileCheck %s
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; RUN: opt -passes=loop-load-elim -S < %s | FileCheck %s
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; Simple st->ld forwarding derived from a lexical backward dep.
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;
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; for (unsigned i = 0; i < 100; i++)
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; A[i+1] = A[i] + B[i];
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target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
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define void @f(i32* noalias nocapture %A, i32* noalias nocapture readonly %B, i64 %N) {
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entry:
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; CHECK: %load_initial = load i32, i32* %A
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br label %for.body
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for.body: ; preds = %for.body, %entry
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; CHECK: %store_forwarded = phi i32 [ %load_initial, %entry ], [ %add, %for.body ]
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%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
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%arrayidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
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%load = load i32, i32* %arrayidx, align 4
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%arrayidx2 = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
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%load_1 = load i32, i32* %arrayidx2, align 4
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; CHECK: %add = add i32 %load_1, %store_forwarded
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%add = add i32 %load_1, %load
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%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
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%arrayidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next
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store i32 %add, i32* %arrayidx_next, align 4
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%exitcond = icmp eq i64 %indvars.iv.next, %N
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br i1 %exitcond, label %for.end, label %for.body
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for.end: ; preds = %for.body
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ret void
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}
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