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