<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi! <div class=""><br class=""></div><div class="">The description looks good!</div><div class=""><br class=""></div><div class="">Although, I can’t get the point how this</div><div class=""><br class=""></div><div class="">> <span style="font-family: Menlo-Regular;" class="">(negative offset from the stack</span></div><div class=""><span style="font-family: Menlo-Regular;" class="">> pointer may appear positive and result is undefined memory access). </span><div><br class=""></div><div>can’t be applied to a constant? Hence, we’d need a check?</div><div><br class=""></div><div>Although, I’m trying to get into Mike’s business again. So it LGTM as a backport.</div><div><br class=""></div><div>Regards,</div><div>Sergos</div><div><br class=""></div><div><br class=""><blockquote type="cite" class=""><div class="">On 28 Oct 2021, at 14:36, Sergey Kaplun <<a href="mailto:skaplun@tarantool.org" class="">skaplun@tarantool.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta charset="UTF-8" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Hi, Sergos!</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Thanks for the review!</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">On 27.10.21, sergos wrote:</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">Hi!<br class=""><br class="">Thanks for the patch, see my comments below.<br class=""><br class="">Regards,<br class="">Sergos<br class=""><br class=""><blockquote type="cite" class="">On 18 Oct 2021, at 21:53, Sergey Kaplun <<a href="mailto:skaplun@tarantool.org" class="">skaplun@tarantool.org</a>> wrote:<br class=""><br class="">From: Mike Pall <mike><br class=""><br class="">Reported by Matthew Burk.<br class=""><br class="">(cherry picked from commit 9f0caad0e43f97a4613850b3874b851cb1bc301d)<br class=""><br class="">The simplify_conv_sext optimization is used for reduction of widening.<br class=""></blockquote><br class="">Whether it is part of narrowing itself?<span class="Apple-converted-space"> </span><br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Not exactly, it is fold optimization that can be used during narrowing.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">lj_opt_narrow_cindex -> lj_opt_fold (in emitir) -> fold_narrow_convert -></span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">lj_opt_narrow_convert -> narrow_conv_emit -> lj_opt_fold -></span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">fold_simplify_conv_sext</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br class=""><blockquote type="cite" class="">cdata indexing narrow optimization uses it for narrowing of a C array<br class=""></blockquote><br class="">The sentence is started with lowercase, making one to track back the start<br class="">of the sentence. “A narrow optimization for cdata…” in conjunction of<br class="">first sentence above should help.<br class=""><br class=""><br class=""><blockquote type="cite" class="">index. The optimization eliminates sign extension for corresponding<br class=""></blockquote><span class="Apple-tab-span" style="white-space: pre;"> </span><span class="Apple-tab-span" style="white-space: pre;"> </span><span class="Apple-tab-span" style="white-space: pre;"> </span><span class="Apple-tab-span" style="white-space: pre;"> </span><span class="Apple-tab-span" style="white-space: pre;"> </span><span class="Apple-tab-span" style="white-space: pre;"> </span><span class="Apple-converted-space"> </span> the<br class=""><br class=""><blockquote type="cite" class="">integer value. However, this conversion cannot be omitted for non<br class="">constant values (for example loading stack slots) as far as their sign<br class="">extension may change. The emitted machine code may be incorrect without<br class=""></blockquote><br class="">I believe you meant ‘with’ the conversion.<span class="Apple-converted-space"> </span><br class=""><br class=""><blockquote type="cite" class="">aforementioned conversion (for example mov instruction instead movsxd is<br class="">used on x86 architecture). As a result the value in a destination<br class=""></blockquote><br class="">The example is too much. Just “negative offset from the stack pointer<br class="">may appear positive and result in undefined memory access”<br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Fixed all your comments, see the updated commit message below.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Branch is force pushed.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">===================================================================</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Fix FOLD rule for strength reduction of widening.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Reported by Matthew Burk.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">(cherry picked from commit 9f0caad0e43f97a4613850b3874b851cb1bc301d)</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">The simplify_conv_sext optimization is used for reduction of widening.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">An indexing narrow optimization for cdata uses it for narrowing of a C</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">array index. The optimization eliminates sign extension for the</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">corresponding integer value. However, this conversion cannot be omitted</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">for non constant values (for example loading stack slots) as far as</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">their sign extension may change. The emitted machine code may be</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">incorrect with aforementioned conversion (negative offset from the stack</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">pointer may appear positive and result is undefined memory access). As a</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">result the value in a destination register during trace execution is</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">invalid.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">This patch allows this optimization only for constant integer values.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Sergey Kaplun:</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">* added the description and the test for the problem</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">===================================================================</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br class=""><blockquote type="cite" class="">register during trace execution is invalid.<br class=""><br class="">This patch allows this optimization only for constant integer values.<br class=""></blockquote><br class="">Should it check if integer - even a constant one - is positive?<span class="Apple-converted-space"> </span><br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">No, why? In fold rule are declared both types: INT64 and UINT64.</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br class=""><blockquote type="cite" class=""><br class="">Sergey Kaplun:<br class="">* added the description and the test for the problem<br class="">---<br class=""><br class="">Tarantool branch: <a href="https://github.com/tarantool/tarantool/tree/skaplun/gh-noticket-fix-fold-simplify-conv-sext" class="">https://github.com/tarantool/tarantool/tree/skaplun/gh-noticket-fix-fold-simplify-conv-sext</a><br class="">Branch: <a href="https://github.com/tarantool/luajit/tree/skaplun/gh-noticket-fix-fold-simplify-conv-sext" class="">https://github.com/tarantool/luajit/tree/skaplun/gh-noticket-fix-fold-simplify-conv-sext</a><br class=""><br class="">src/lj_opt_fold.c | 2 +-<br class="">.../lj-fix-fold-simplify-conv-sext.test.lua | 35 +++++++++++++++++++<br class="">2 files changed, 36 insertions(+), 1 deletion(-)<br class="">create mode 100644 test/tarantool-tests/lj-fix-fold-simplify-conv-sext.test.lua<br class=""><br class="">diff --git a/src/lj_opt_fold.c b/src/lj_opt_fold.c<br class="">index 3c508062..276dc040 100644<br class="">--- a/src/lj_opt_fold.c<br class="">+++ b/src/lj_opt_fold.c<br class="">@@ -1227,7 +1227,7 @@ LJFOLDF(simplify_conv_sext)<br class=""> if (ref == J->scev.idx) {<br class=""> IRRef lo = J->scev.dir ? J->scev.start : J->scev.stop;<br class=""> lua_assert(irt_isint(J->scev.t));<br class="">- if (lo && IR(lo)->i + ofs >= 0) {<br class="">+ if (lo && IR(lo)->o == IR_KINT && IR(lo)->i + ofs >= 0) {<br class=""> ok_reduce:<br class="">#if LJ_TARGET_X64<br class=""> /* Eliminate widening. All 32 bit ops do an implicit zero-extension. */<br class="">diff --git a/test/tarantool-tests/lj-fix-fold-simplify-conv-sext.test.lua b/test/tarantool-tests/lj-fix-fold-simplify-conv-sext.test.lua<br class="">new file mode 100644<br class="">index 00000000..bd3738c5<br class="">--- /dev/null<br class="">+++ b/test/tarantool-tests/lj-fix-fold-simplify-conv-sext.test.lua<br class="">@@ -0,0 +1,35 @@<br class="">+local tap = require('tap')<br class="">+local ffi = require('ffi')<br class="">+<br class="">+local test = tap.test('lj-fix-fold-simplify-conv-sext')<br class="">+<br class="">+local NSAMPLES = 4<br class="">+local NTEST = NSAMPLES * 2 + 1<br class=""></blockquote></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Also fixed typo here: s/+/-/</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" class="">+test:plan(NTEST)<br class="">+<br class="">+local samples = ffi.new('int [?]', NSAMPLES)<br class="">+<br class="">+-- Prepare data.<br class="">+for i = 0, NSAMPLES - 1 do samples[i] = i end<br class="">+<br class="">+local expected = {3, 2, 1, 0, 3, 2, 1}<br class="">+<br class="">+local START = 3<br class="">+local STOP = -START<br class="">+<br class="">+local results = {}<br class="">+jit.opt.start('hotloop=1')<br class="">+for i = START, STOP, -1 do<br class="">+ -- While recording cdata indexing the fold CONV SEXT<br class="">+ -- optimization eliminate sign extension for the corresponding<br class="">+ -- non constant value (i.e. stack slot). As a result the read<br class="">+ -- out of bounds was occurring.<br class="">+ results[#results + 1] = samples[i % NSAMPLES]<br class="">+end<br class="">+<br class="">+for i = 1, NTEST do<br class="">+ test:ok(results[i] == expected[i], 'correct cdata indexing')<br class="">+end<br class="">+<br class="">+os.exit(test:check() and 0 or 1)<br class="">+<br class="">--<span class="Apple-converted-space"> </span><br class="">2.31.0<br class=""><br class=""></blockquote><br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">--<span class="Apple-converted-space"> </span></span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Best regards,</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 11px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Sergey Kaplun</span></div></blockquote></div><br class=""></div></body></html>