<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Feb 12, 2013, at 7:01 PM, Eric Christopher <<a href="mailto:echristo@gmail.com">echristo@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="font-family: Optima; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; ">My idea is that we could track what location it is separately via abi and encode that and then any changes, but I was mostly thinking of not copying the incoming value into an alloca in the front end and rather having the dbg.value reference the function argument rather than the alloca. I'm not sure what changes we'd need to make in allocation to track this though offhand, my guess is some. The dbg.value on entry should have the function argument via the prologue (or we just add them as part of the prologue) which will have the ABI location and then any changes later would be marked by a dbg.value as well if we spilled or killed the argument value (in the case of unused arguments), but we'd be correct at the end of the prologue.</div><div style="font-family: Optima; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><br></div><div style="font-family: Optima; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; ">Sound plausible?</div></blockquote></div><br><div>Are you thinking of -O0 code here? The LDV pass and the coalescer only run when optimizing.</div><div><br></div><div>/jakob</div><div><br></div></body></html>