43 lines
1.6 KiB
LLVM
43 lines
1.6 KiB
LLVM
; RUN: opt -S -loop-load-elim < %s | FileCheck %s
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; We can't hoist conditional loads to the preheader for the initial value.
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; E.g. in the loop below we'd access array[-1] if we did:
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;
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; for(int i = 0 ; i < n ; i++ )
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; array[i] = ( i > 0 ? array[i - 1] : 0 ) + 4;
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target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-apple-macosx10.11.0"
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define void @f(i32* %array, i32 %n) {
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entry:
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%cmp10 = icmp sgt i32 %n, 0
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br i1 %cmp10, label %for.body, label %for.cond.cleanup
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for.cond.cleanup: ; preds = %cond.end, %entry
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ret void
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for.body: ; preds = %entry, %cond.end
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%indvars.iv = phi i64 [ %indvars.iv.next, %cond.end ], [ 0, %entry ]
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; CHECK-NOT: %store_forwarded = phi
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%cmp1 = icmp sgt i64 %indvars.iv, 0
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br i1 %cmp1, label %cond.true, label %cond.end
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cond.true: ; preds = %for.body
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%0 = add nsw i64 %indvars.iv, -1
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%arrayidx = getelementptr inbounds i32, i32* %array, i64 %0
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%1 = load i32, i32* %arrayidx, align 4
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br label %cond.end
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cond.end: ; preds = %for.body, %cond.true
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%cond = phi i32 [ %1, %cond.true ], [ 0, %for.body ]
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; CHECK: %cond = phi i32 [ %1, %cond.true ], [ 0, %for.body ]
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%add = add nsw i32 %cond, 4
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%arrayidx3 = getelementptr inbounds i32, i32* %array, i64 %indvars.iv
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store i32 %add, i32* %arrayidx3, align 4
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%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
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%lftr.wideiv = trunc i64 %indvars.iv.next to i32
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%exitcond = icmp eq i32 %lftr.wideiv, %n
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br i1 %exitcond, label %for.cond.cleanup, label %for.body
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}
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