From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeffrey A Law To: "Martin v. Loewis" Cc: hjl@varesearch.com, medtekh@orc.ru, egcs@egcs.cygnus.com Subject: Re: gcc-2.7 creates faster code than pgcc-1.1.1 Date: Thu, 04 Mar 1999 18:08:00 -0000 Message-id: <13494.920599668@hurl.cygnus.com> In-reply-to: Your message of Fri, 05 Mar 1999 01:01:59 MST. < 199903050001.BAA00973@mira.isdn.cs.tu-berlin.de > References: <199903050001.BAA00973@mira.isdn.cs.tu-berlin.de> X-SW-Source: 1999-03/msg00197.html In message < 199903050001.BAA00973@mira.isdn.cs.tu-berlin.de >you write: > > - if ((TARGET_ZERO_EXTEND_WITH_AND || REGNO (operands[0]) == 0) > > + if ((TARGET_ZERO_EXTEND_WITH_AND || (0 & REGNO (operands[0]) == 0)) > > It's late, so I'm probably going to say stupid things, but ... > > Isn't (0 & REGNO (operands[0]) == 0) always 0? Why isn't the condition > just deleted? Disabling the code like that is actually the wrong thing to do for certain processor variants. I need to dust off my changes to this code which do the right thing when optimizing for size, PPro, Pent and older x86 variants. It's not as simple as just deleting the test like that. jeff From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeffrey A Law To: "Martin v. Loewis" Cc: hjl@varesearch.com, medtekh@orc.ru, egcs@egcs.cygnus.com Subject: Re: gcc-2.7 creates faster code than pgcc-1.1.1 Date: Wed, 31 Mar 1999 23:46:00 -0000 Message-ID: <13494.920599668@hurl.cygnus.com> References: <199903050001.BAA00973@mira.isdn.cs.tu-berlin.de> X-SW-Source: 1999-03n/msg00198.html Message-ID: <19990331234600.yyNEIbP0nUBDNSZm2-e4Vipldrm6ub2vzwwf3RQEc8k@z> In message < 199903050001.BAA00973@mira.isdn.cs.tu-berlin.de >you write: > > - if ((TARGET_ZERO_EXTEND_WITH_AND || REGNO (operands[0]) == 0) > > + if ((TARGET_ZERO_EXTEND_WITH_AND || (0 & REGNO (operands[0]) == 0)) > > It's late, so I'm probably going to say stupid things, but ... > > Isn't (0 & REGNO (operands[0]) == 0) always 0? Why isn't the condition > just deleted? Disabling the code like that is actually the wrong thing to do for certain processor variants. I need to dust off my changes to this code which do the right thing when optimizing for size, PPro, Pent and older x86 variants. It's not as simple as just deleting the test like that. jeff