Re: [Valgrind-developers] [PATCH 1/2] x86: optimize XCHG to MOV for same-register forms
Christian Ludloff <[email protected]>
| Newsgroups | gmane.comp.gnu.binutils |
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| Message-ID | <CAKSQd8U6E=xOBoCF7EgGBNyc_Hiq+8vKL2FTWrxd=cx6w+pW3Q@mail.gmail.com> |
> https://sourceware.org/bugzilla/show_bug.cgi?id=34343 There is an additional case that breaks because of the optimization. Transmeta processors provided translation control via XCHG eSP,eSP. 67h,87h,E4h forced BOT on Crusoe, i.e. begin-of-translation. 66h,87h,E4h forced EOT on Crusoe, i.e. end-of-translation. 67h,87h,E4h forced BOT+EOT on Efficeon, i.e. break-translation-here. 66h,87h,E4h no longer forced EOT on Efficeon. Granted, Transmeta processors are historical by now. Still... this gas optimization is... perhaps better left to higher level tools. -- C.