Optimizing parameters in C function for MIPs/gcc -


i'm trying optimize code, , discovered gcc treats 2 uint_64 parameters differently struct 2 uint_64's in it. if have:

void testfn2parm( uint64_t p1, uint64_t p2 ) {     tp[0] = p1;     tp[1] = p2; }

it resolves to:

void testfn2parm( uint64_t p1, uint64_t p2 ) { tp[0] = p1; 1d18:       3c020000        lui     v0,0x0 1d1c:       fc440000        sd      a0,0(v0) tp[1] = p2; 1d20:       64430000        daddiu  v1,v0,0 1d24:       03e00008        jr      ra 1d28:       fc650008        sd      a1,8(v1) 1d2c:       00000000        nop

where a0 , a1 values of parameters -- no stack access. however, if do:

struct ts {      uint64_t    t64[2]; };  void testfntsparm( struct ts ts ) {     tp[0] = ts.t64[0];     tp[1] = ts.t64[1]; }

which same thing, get:

void testfntsparm( struct ts ts ) { 1d88:       dc830008        ld      v1,8(a0) tp[0] = ts.t64[0]; 1d8c:       3c020000        lui     v0,0x0 1d90:       dc840000        ld      a0,0(a0) tp[1] = ts.t64[1]; 1d94:       64450000        daddiu  a1,v0,0 1d98:       fca30008        sd      v1,8(a1) 1d9c:       03e00008        jr      ra 1da0:       fc440000        sd      a0,0(v0) 1da4:       00000000        nop

notice ld commands. in case a0 starts stack pointer. i'm wondering if there's clever ways around this, doesn't involve rewriting calling functions? (i'm using cross-compiler mips based on gcc 4.7)


Comments

Post a Comment

Popular posts from this blog

Command prompt result in label. Python 2.7 -

i want put result(output) of shell command label. command works, label shows "0", however, in command prompt, result shown correctly, need showed in label. doing ubuntu. myg1 = button(root, text="rodyti informacija", command=lambda: gauti()) myg1.pack(side=bottom) def gauti(): imti = tekstas.get("1.0", "end-1c") info = subprocess.call("id '{imti}' ".format(imti=imti), shell=true) w = label(root, text= info) w.pack(side = bottom) subprocess.call() returns exit code of process created (in case 0 success). if want text output of process, should instead call subprocess.check_output() .
Read more

javascript - How do I use URL parameters to change link href on page? -

i change href value of link using url parameters. example: default <a id="dlink" href="link-1">link</a> but, when user goes https://url.com/?dlink=link-2 it swaps out link new link <a id="dlink" href="link-2">link</a> first need value url. if you're not using javascript framework can create function using jquery. please check get url parameter jquery or how query string values in js it. after that, element "a" id , set value there. $("#dlink").attr("href", hreffromparam);
Read more

amazon web services - AWS Route53 Trying To Get Site To Resolve To www -

so have domain nameservers pointed aws route 53. site hosted on ec2 instance , reachable resolves site.com, if input www.site.com. i'm curious how site resolve www.site.com. have under route53 domains hosted zone 2 additional record sets outside of ns , soa: a site.com ec2 elastic ip cname www.site.com ec2 public dns i can reach site using both site.com , www.site.com, resolve site.com. there way make if enter either, resolves www.site.com? at first, both should record set. a site.com ec2 elastic ip www.site.com ec2 elastic ip and need redirect setting in web server (nginx, apache, ..) following. (source: how redirect www non-www nginx on centos 7 ) redirect non-www www if want redirect users plain, non-www domain www domain, add server block: server { server_name example.com; return 301 $scheme://www.example.com$request_uri; } save , exit. configures nginx redirect requests "example.com" "www.example.com". not...
Read more