<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 2010-01-27, at 9:28 AM, Eliot Miranda wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div class="gmail_quote"><div><div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;"># define DECL_MAYBE_SQ_GLOBAL_STRUCT register struct foo * foo = &fum;</span></font></div>
<div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;"># define DECL_MAYBE_VOLATILE_SQ_GLOBAL_STRUCT volatile register struct foo * foo = &fum;</span></font></div></div></div></div></blockquote><br></div><div>BTW the <span class="Apple-style-span" style="font-family: 'courier new', monospace; font-size: large; ">register struct foo * foo = &fum stuck in the different procedures, (interp() can be different btw), </span></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;">was based on usage, I think use of > twice or something then it was inserted, otherwise it was not. </span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;"><br></span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;">At the time on the PowerPC the compiler would need 2 instructions to reference foo->erk, loading foo out of the global area, then doing foo->fum</span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;">If foo was local to the procedure then it was one instruction taking foo in register N and loading with offset. So you needed > 2 references to </span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;">justify the cost of loading into a register then using. The use of register keyword over time is respected or not by the compiler and compiler version.</span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;"><br></span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;">For interp() the construct for referring to foo can significantly effect bytecode rates again depending on the compiler etc. </span></font></div><div><font class="Apple-style-span" face="'courier new', monospace"><span class="Apple-style-span" style="font-size: large;"><br></span></font></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">--</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">===========================================================================</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">John M. McIntosh <<a href="mailto:johnmci@smalltalkconsulting.com">johnmci@smalltalkconsulting.com</a>> Twitter: squeaker68882</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Corporate Smalltalk Consulting Ltd. <a href="http://www.smalltalkconsulting.com">http://www.smalltalkconsulting.com</a></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">===========================================================================</font></div><div><br></div></div></div></div></div></div></span></div></span><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline">
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