This is the mail archive of the
mailing list for the GCC project.
cmp and bcond patterns in md
- To: GCC Mailing List <gcc at gcc dot gnu dot org>
- Subject: cmp and bcond patterns in md
- From: Soubhik Bhattacharya <soubhik at cse dot iitk dot ac dot in>
- Date: Fri, 11 May 2001 15:29:16 +0530 (IST)
- Organization: Dept of Computer Science IIT Kanpur
i'm trying to port GCC to a hypothetical processor. right now i'm more
worried about the simplicity of the machine description and less about the
efficiency of the compiler / quality of the compiled code...
i've the following query:
the processor does not have any condition code register. however it has
branch instructions which compare two registers and based on the
result of the comparison, decide to branch / not to branch (very much
mips-like situation). now it seems to me that this single machine instr
does the work of both cmp and bcond patterns. so can i simply specify the
assembly template of cmp as a null string (or nop) and then generate the
branch instr with the bcond pattern?..... this seems a bit too
simple-minded to me. shud this work?
any insight will be highly appreciated.....