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From: | "Andrew Jones" <xluminous AT hotmail DOT com> |
Newsgroups: | comp.os.msdos.djgpp |
References: | <fyoofqnexgrpubet DOT fniy770 DOT pminews AT nntp DOT generation DOT net> |
Subject: | Re: GCC optimization |
Lines: | 35 |
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Message-ID: | <4VLa4.70142$X47.388252@quark.idirect.com> |
Date: | Thu, 30 Dec 1999 16:39:28 GMT |
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NNTP-Posting-Date: | Thu, 30 Dec 1999 11:39:28 EST |
Organization: | Internet Direct - http://www.mydirect.com |
To: | djgpp AT delorie DOT com |
DJ-Gateway: | from newsgroup comp.os.msdos.djgpp |
Reply-To: | djgpp AT delorie DOT com |
> Does GCC optimize "something*1024" into "something << 10"? Let's see. TEST.C ~~~~ int glob; int main(void) { return(glob * 1024); } gcc -c -S test.c GLOB.S ~~~~~ [...] movl _glob,%eax movl %eax,%edx movl %edx,%ecx sall $10,%ecx movl %ecx,%eax [...] In a word: YES. Andrew Jones.
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