site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com On 4 nov. 06, at 20:09, Eric Albert wrote: gcc will realign the stack if it's given the -mstackrealign switch. Excerpt from man gcc Cédric _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... That's not actually necessary, though I can't remember if the compiler might do it anyway. -mstackrealign Realign the stack at entry. On the Intel x86, the - mstackrealign option will generate an alternate prologue/epilogue that realigns the runtime stack. This supports mixing legacy codes that keep a 4-byte aligned stack with modern codes that keep a 16- byte stack for SSE compatibility. The alternate prologue and epilogue are slower and bigger than the regular ones, and they require one dedi- cated register for the entire function. This also lowers the num- ber of registers available if used in conjunction with the "reg- parm" attribute. Nested functions encountered while - mstackrealign is on will generate warnings, and they will not realign the stack when called. This email sent to site_archiver@lists.apple.com