forked from OSchip/llvm-project
52 lines
2.0 KiB
LLVM
52 lines
2.0 KiB
LLVM
; RUN: opt -analyze --loop-accesses %s | FileCheck %s
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; This test verifies run-time boundary check of memory accesses.
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; The original loop:
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; void fastCopy(const char* src, char* op) {
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; int len = 32;
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; while (len > 0) {
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; *(reinterpret_cast<long long*>(op)) = *(reinterpret_cast<const long long*>(src));
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; src += 8;
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; op += 8;
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; len -= 8;
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; }
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; }
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; Boundaries calculations before this patch:
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; (Low: %src High: (24 + %src))
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; and the actual distance between two pointers was 31, (%op - %src = 31)
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; IsConflict = (24 > 31) = false -> execution is directed to the vectorized loop.
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; The loop was vectorized to 4, 32 byte memory access ( <4 x i64> ),
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; store a value at *%op touched memory under *%src.
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;CHECK: Printing analysis 'Loop Access Analysis' for function 'fastCopy'
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;CHECK: (Low: %op High: (32 + %op))
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;CHECK: (Low: %src High: (32 + %src))
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define void @fastCopy(i8* nocapture readonly %src, i8* nocapture %op) {
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entry:
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br label %while.body.preheader
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while.body.preheader: ; preds = %entry
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br label %while.body
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while.body: ; preds = %while.body.preheader, %while.body
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%len.addr.07 = phi i32 [ %sub, %while.body ], [ 32, %while.body.preheader ]
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%op.addr.06 = phi i8* [ %add.ptr1, %while.body ], [ %op, %while.body.preheader ]
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%src.addr.05 = phi i8* [ %add.ptr, %while.body ], [ %src, %while.body.preheader ]
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%0 = bitcast i8* %src.addr.05 to i64*
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%1 = load i64, i64* %0, align 8
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%2 = bitcast i8* %op.addr.06 to i64*
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store i64 %1, i64* %2, align 8
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%add.ptr = getelementptr inbounds i8, i8* %src.addr.05, i64 8
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%add.ptr1 = getelementptr inbounds i8, i8* %op.addr.06, i64 8
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%sub = add nsw i32 %len.addr.07, -8
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%cmp = icmp sgt i32 %len.addr.07, 8
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br i1 %cmp, label %while.body, label %while.end.loopexit
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while.end.loopexit: ; preds = %while.body
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br label %while.end
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while.end: ; preds = %while.end.loopexit, %entry
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ret void
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}
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