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Article #51956Re: asm() constraints
From: Bruce Evans
Date: Mon, 01 Mar 1993 07:28
Date: Mon, 01 Mar 1993 07:28
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1387 bytes
In article <1993Feb26.062103.20601@advtech.uswest.com> huntting@advtech.uswest.com (Brad Huntting) writes: > >But isn't quite correct. Do I need to specify registers in the >declaration of _x and _y? How do I tell it that the stack will be >poped? Do I need to add something to the last field in the asm() to >tell it that the floating point status word will be clobbered? gcc-2 has a new constraints for this: "t" for %st(0) and "u" for %st(1). I don't think this is documented except in the sources (i386.h REG_CLASS_FROM_LETTER). I don't think you can tell it that the stack will be popped. You probably have to push some junk onto the stack. You can tell it that the result is in %st(1). I think it assumes that the status word will be clobbered. Bruce -- Bruce Evans (bde@runx.oz.au)
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 11318c,6ef6a338c52a498a X-Google-Attributes: gid11318c,public X-Google-ArrivalTime: 1993-02-28 23:28:26 PST Newsgroups: gnu.gcc.help Path: arc1-ca.pugleaf.net!sparky!uunet!stanford.edu!agate!spool.mu.edu!sgiblab!munnari.oz.au!metro!ipso!runxtsa!bde From: bde@runx.oz.au (Bruce Evans) Subject: Re: asm() constraints Message-ID: <1993Mar1.072826.16476@runx.oz.au> Organization: RUNX Un*x Timeshare. Sydney, Australia. References: <1993Feb26.062103.20601@advtech.uswest.com> Date: Mon, 1 Mar 93 07:28:26 GMT Lines: 20