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Article #50901Branch prediction pragma
From: James Tsillas
Date: Sat, 24 Jul 1993 16:16
Date: Sat, 24 Jul 1993 16:16
19 lines
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1480 bytes
Has any consideration been given to implementing a pragma to indicate branch condition is more common for purposes of optimization. On most CPU's the cycles for a branch are more expensive than falling through the branch and engineers will frequently construct elaborate compound if-else clauses to ensure that the most frequently taken path has the fewest branches. A major win for gcc would be to provide a pragma which says: this given block is more frequently chosen by this if-condition. -Jim. -- *** James Tsillas jtsilla@damon.ccs.northeastern.edu *** *** Work: (508)898-2800, Home: (617)641-0513 *** *** "He is after me. Jim is after him." *** *** - Hop on Pop, Dr. Seuss ***
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 11318c,4e9ca1c0df4c621f,start X-Google-Attributes: gid11318c,public X-Google-ArrivalTime: 1993-07-24 08:56:26 PST Newsgroups: gnu.gcc.help Path: arc1-ca.pugleaf.net!gmd.de!Germany.EU.net!news.dfn.de!darwin.sura.net!howland.reston.ans.net!noc.near.net!lynx!random.ccs.northeastern.edu!news From: jtsilla@dec5200b.ccs.northeastern.edu (James Tsillas) Subject: Branch prediction pragma Message-ID: <JTSILLA.93Jul24111624@dec5200b.ccs.northeastern.edu> Sender: news@random.ccs.northeastern.edu Nntp-Posting-Host: dec5200b.ccs.northeastern.edu Organization: Northeastern University, Boston, MA Distribution: gnu Date: Sat, 24 Jul 1993 16:16:24 GMT Lines: 19