forums.ps2dev.org Forum Index forums.ps2dev.org
Homebrew PS2, PSP & PS3 Development Discussions
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

freeze psp with asm inline function

 
Post new topic   Reply to topic    forums.ps2dev.org Forum Index -> PSP Development
View previous topic :: View next topic  
Author Message
gff_cruner



Joined: 01 May 2006
Posts: 11
Location: La Coruna - Spain
PostPosted: Mon May 01, 2006 11:29 am    Post subject: freeze psp with asm inline function Reply with quote
Hi everyone.
I am new in psp programing, in inline assembly coding and I am new in this forum too :).
I am trying to code a simple little 3d engine. Now, I was coding a simple function to multiply two matrix, but i have some problems with inline assembly code.
This is my code:

Code:
void multMatrix(float *matrix1, float *matrix2)
{
   __asm__ volatile(
      "lv.q c000,  0 + %0\n"
      "lv.q c010, 16 + %0\n"
      "lv.q c020, 32 + %0\n"
      "lv.q c030, 48 + %0\n"
      "lv.q c100,  0 + %1\n"
      "lv.q c110, 16 + %1\n"
      "lv.q c120, 32 + %1\n"
      "lv.q c130, 48 + %1\n"
      "vmmul.q m200, m000, m100\n"
      "sv.q c200,  0 + %1\n"
      "sv.q c210, 16 + %1\n"
      "sv.q c220, 32 + %1\n"
      "sv.q c230, 48 + %1\n"
      ::"m" (matrix1[0]),
        "m" (matrix2[0]));
}


I donīt know whatīs wrong, but I only get a freeze psp with this code.
Maybe my problem is shift registers. I donīt know.

Can someone help me to fix this??

Edited:
I have discovered that always I use lv or sv to load and store data, I get a freeze psp. But when I use mtv/mfv it works.
Generally, somebody knows how to save/load a 4x4 matrix to/from vfpu using simple vfpu instructions (without GUM)??

Thanks
Back to top
View user's profile Send private message
starman2049



Joined: 19 Sep 2005
Posts: 75
PostPosted: Thu May 04, 2006 8:15 am    Post subject: Reply with quote
lv.q and sv.q require data to be quadword aligned. meaning the starting address of the argumants needs to be multiples of 16 bytes.
Back to top
View user's profile Send private message
gff_cruner



Joined: 01 May 2006
Posts: 11
Location: La Coruna - Spain
PostPosted: Thu May 04, 2006 9:05 am    Post subject: Reply with quote
starman2049 wrote:
lv.q and sv.q require data to be quadword aligned. meaning the starting address of the argumants needs to be multiples of 16 bytes.


Thanks starman2049. I didnīt realize. Iīll test the code trying to align the bytes that compose the matrix that way. But, implies this that I have to realign the data pointed by matrix1 and matrix2 before the asm code, isnīt? Then, is not enough to shift the registers using '+'? (Sorry for this kind of questions, I am really n00b in asm coding)

Thanks a lot for the reply! ;)
Back to top
View user's profile Send private message
starman2049



Joined: 19 Sep 2005
Posts: 75
PostPosted: Thu May 04, 2006 9:53 am    Post subject: Reply with quote
You have to make sure that your matrices have 16 byte alignment. Meaning that the starting address of the [0][0] element is a multiple of 16 bytes for each matrix.

I define a float matrix as:
Code:
typedef float   FMATRIX[4][4] __attribute__((aligned(16)));


I have sw and hw versions of some of these functions becasue it is not always possible to make sure a matrix (or more commonly a vector) is aligned to 16 bytes, particularily when working on complex streams such as particle effects, etc where you might pack arrays so they are exactly a cache line (64 bytes) for cache performance, but then data might not be aligned inside the array for best VFPU/lq/sq usage. Sometimes it's a tradeoff...
Back to top
View user's profile Send private message
chp



Joined: 23 Jun 2004
Posts: 313
PostPosted: Thu May 04, 2006 9:52 pm    Post subject: Reply with quote
You can also use the unaligned version if you cannot guarantee that something is aligned to qword boundary (like when you declare a matrix on the stack since GCC doesn't align stack variables), ulv.q/usv.q exist for this purpose. They are actually macro-instructions for lvl/lvr and svl/svr, but you don't want to spend your time computing offsets every time you use them so I recommend the macro-versions. :) And instead of reinventing the wheel you can look at the code in pspgum_vfpu.c, it should give good ideas on how to work with the vfpu.
_________________
GE Dominator
Back to top
View user's profile Send private message
gff_cruner



Joined: 01 May 2006
Posts: 11
Location: La Coruna - Spain
PostPosted: Mon May 08, 2006 5:13 am    Post subject: Reply with quote
First of all, thank you both. Your replies were very helpful for me ;)

My first try was to align the bytes of the matrix using "__attribute__((aligned(16)))", as starman2049 said, but the function returned strange results (I don't know why).
I followed the advice from chp as well, and after some tests and some reading of pspvfpu.h, psptypes.h and pspgum_vfpu.h, I realized that the vfputypes.h includes declarations of matrices built as structs:

Code:
typedef struct ScePspIMatrix4 {
   ScePspIVector4    x;
   ScePspIVector4    y;
   ScePspIVector4    z;
   ScePspIVector4    w;
} ScePspIMatrix4 __attribute__((aligned(16)));


...which also use the alignement that starman said.

I used this struct (where the vectors are also declared as structs) with this function (thanks to pspgum_vfpu.h code):

Code:
void aceMultMatrix(ScePspFMatrix4 *m0, ScePspFMatrix4 *m1)
{
   pspvfpu_use_matrices(pspvfpu_initcontext(), 0, VMAT0 | VMAT1 |VMAT2);

   __asm__ volatile (
      "ulv.q r000, 0+%0\n"
      "ulv.q r001, 16+%0\n"
      "ulv.q r002, 32+%0\n"
      "ulv.q r003, 48+%0\n"

      "ulv.q r100, 0+%1\n"
      "ulv.q r101, 16+%1\n"
      "ulv.q r102, 32+%1\n"
      "ulv.q r103, 48+%1\n"

      "vmmul.q   m200, m000, m100\n"

      "usv.q r200, 0+%0\n"
      "usv.q r201, 16+%0\n"
      "usv.q r202, 32+%0\n"
      "usv.q r203, 48+%0\n"
      :"+m"(*m1): "m"(*m0));
}


And finally, IT WORKED ;)

Anyway, it's quite strange using these matrices as structs and it's hard to code this way when your matrices are declared as arrays, so I'm looking for a way to do it that way. I'll be very thankfully if somebody gives me some kind of hint about this topic.
Back to top
View user's profile Send private message
Rekai



Joined: 12 Sep 2006
Posts: 5
PostPosted: Fri Sep 29, 2006 5:49 am    Post subject: Reply with quote
well I have not actually coded it but you sould be able to overload the = operator to look something like this:

Code:

ScePspFMatrix4 operator=(float** m){
   ScePspFMatrix4 ret={{m[0][0],m[0][1],m[0][2],m[0][3],},
          {m[1][0],m[1][1],m[1][2],m[1][3],},
          {m[2][0],m[2][1],m[2][2],m[2][3],},
          {m[3][0],m[3][1],m[3][2],m[3][3],},}
   return ret;
}


that sould do, and if doesnt, try making a macro to switch from one type to the other.
Back to top
View user's profile Send private message
gff_cruner



Joined: 01 May 2006
Posts: 11
Location: La Coruna - Spain
PostPosted: Fri Oct 06, 2006 1:40 am    Post subject: Reply with quote
Thanks Rekai, i will use it
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    forums.ps2dev.org Forum Index -> PSP Development All times are GMT + 10 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group