• Shahid (16/16) Jun 02 2011 I'm working with 64bit iasm and I would like to have some constant data
• Shahid (16/16) Jun 03 2011 I made the Following change to backend/elfobj.c

Shahid <Shahid party.van> writes:

I'm working with 64bit iasm and I would like to have some constant data 
16 byte aligned.

I have near the top of my source file:

__gshared immutable 
{
	ulong[2] sse_0F = [0x0F0F_0F0F_0F0F_0F0F,0x0F0F_0F0F_0F0F_0F0F];
	ulong[2] sse_30 = [0x3030_3030_3030_3030,0x3030_3030_3030_3030];
}

However getting this to be 16 byte aligned is a bit of a headache.

I noticed in the DMD changelog:

DMD 2.007
"Data items in static data segment >= 16 bytes in size are now paragraph 
aligned."

I have no idea what "paragraph aligned" means.

If it's not possible, could someone point me whereabouts in the dmd 
source is responsible for static data alignment?

Shahid <Shahid party.van> writes:

I made the Following change to backend/elfobj.c
I have no idea what I just did but it has solved my problem
Could anyone explain?

-- align16.patch --

diff --u a/src/backend/elfobj.c b/src/backend/elfobj.c
--- a/src/backend/elfobj.c
+++ b/src/backend/elfobj.c
   -683,7 +683,7    void obj_init(Outbuffer *objbuf, const char *filename,
const char *csegname)
         elf_newsection2(0,               SHT_NULL,   0,                
0,0,0,0,0, 0,0);
         elf_newsection2(NAMIDX_TEXT,SHT_PROGDEF,SHF_ALLOC|SHF_
XECINSTR,0,0,0,0,0, 4,0);
         elf_newsection2(NAMIDX_RELTEXT,SHT_RELA, 0,0,0,0,SHI_SYMTAB,    
SHI_TEXT, 8,0x18);
-        elf_newsection2(NAMIDX_DATA,SHT_PROGDEF,SHF_ALLOC|SHF_WRITE,   
0,0,0,0,0, 8,0);
+        elf_newsection2(NAMIDX_DATA,SHT_PROGDEF,SHF_ALLOC|SHF_WRITE,   
0,0,0,0,0, 16,0);
         elf_newsection2(NAMIDX_RELDATA64,SHT_RELA, 0,0,0,0,SHI_SYMTAB,  
SHI_DATA, 8,0x18);
         elf_newsection2(NAMIDX_BSS, SHT_NOBITS,SHF_ALLOC|SHF_WRITE,    
0,0,0,0,0, 16,0);
         elf_newsection2(NAMIDX_RODATA,SHT_PROGDEF,SHF_ALLOC,           
0,0,0,0,0, 16,0);