Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!mips!rogerk
From: rogerk@mips.com (Roger B.A. Klorese)
Newsgroups: comp.sys.mips
Subject: Re: li.s,li.d
Message-ID: <1691@spim.mips.COM>
Date: 1 Apr 91 20:28:59 GMT
References: <1991Apr1.182811.28382@aero.org>
Sender: news@mips.COM
Organization: MIPS Computer Systems, Sunnyvale, California
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In article <1991Apr1.182811.28382@aero.org> jordan@aero.org (Larry M. Jordan) writes:
>
>Any ideas how these two assembler macros (li.s, li.d) are
>really implemented?

Yes, they are implemented as load-word-to-coprocessor-1 (lwc1) instructions
or pairs.  They "immediate" values are stored in the .lit4 (single) and
.lit8 (double) sections.

>Also, (and this may be the solution to my question) is
>there a disassembler for the .o files?  The .s files, I'm
>afraid, hide too much of what is going on--I really want to
>know what machine instructions are generated.


Script started on Mon Apr  1 12:24:00 1991
% [tecate:rogerk] 101) cat foo.s
.set noreorder
li.s    $f0, 1.23456e+5
nop
li.d        $f2, 2.46810121416e+123
% [tecate:rogerk] 102) as foo.s
% [tecate:rogerk] 103) size a.out

Size of a.out:48        

        Section         Size      Physical Address    Virtual Address

          .text          16                0                  0 
          .lit8          16               16                 16 
          .lit4          16               32                 32 
% [tecate:rogerk] 104) dis a.out
  0x0:  c7808020        lwc1    $f0,-32736(gp)
  0x4:  00000000        nop
  0x8:  c7838010        lwc1    $f3,-32752(gp)
  0xc:  c7828014        lwc1    $f2,-32748(gp)
% [tecate:rogerk] 105) dis -s .lit8 a.out
  0x10: 598dde5b        blezl   t4,0xffff7980
  0x14: ea6964fd        swc2    $9,25853(s3)
  0x18: 00000000        nop
  0x1c: 00000000        nop
% [tecate:rogerk] 106) dis -s .lit4 a.out
  0x20: 47f12000        
  0x24: 00000000        nop
  0x28: 00000000        nop
  0x2c: 00000000        nop
% [tecate:rogerk] 107) exit
% [tecate:rogerk] 108) 

script done on Mon Apr  1 12:24:58 1991
-- 
ROGER B.A. KLORESE                                  MIPS Computer Systems, Inc.
MS 6-05    930 DeGuigne Dr.   Sunnyvale, CA  94088              +1 408 524-7421
"10 years of Reagan/Bush have brought us to a new place: postconstitutional
America." - Jon Carroll     rogerk@mips.COM | {ames,decwrl,pyramid}!mips!rogerk