Rewrite the JDIMENSION argument management for x86 64-bit assembly to

simd/jdclrss2-64.asm

 ;
 ; jdclrss2-64.asm - colorspace conversion (64-bit SSE2)
 ;
 ; Copyright 2009, 2012 Pierre Ossman <ossman@cendio.se> for Cendio AB
 ; Copyright 2009, 2012 D. R. Commander
 ;
 ; Based on
 ; x86 SIMD extension for IJG JPEG library
 ; Copyright (C) 1999-2006, MIYASAKA Masaru.
 ; For conditions of distribution and use, see copyright notice in jsimdext.inc
@@ skipping 34 matching lines @@
         push    rbp
         mov     rax,rsp                         ; rax = original rbp
         sub     rsp, byte 4
         and     rsp, byte (-SIZEOF_XMMWORD)     ; align to 128 bits
         mov     [rsp],rax
         mov     rbp,rsp                         ; rbp = aligned rbp
         lea     rsp, [wk(0)]
         collect_args
         push    rbx
 
-        mov     rcx, r10        ; num_cols
+        mov     ecx, r10d       ; num_cols
         test    rcx,rcx
         jz      near .return
 
         push    rcx
 
         mov     rdi, r11
-        mov     rcx, r12
+        mov     ecx, r12d
         mov     rsi, JSAMPARRAY [rdi+0*SIZEOF_JSAMPARRAY]
         mov     rbx, JSAMPARRAY [rdi+1*SIZEOF_JSAMPARRAY]
         mov     rdx, JSAMPARRAY [rdi+2*SIZEOF_JSAMPARRAY]
         lea     rsi, [rsi+rcx*SIZEOF_JSAMPROW]
         lea     rbx, [rbx+rcx*SIZEOF_JSAMPROW]
         lea     rdx, [rdx+rcx*SIZEOF_JSAMPROW]
 
         pop     rcx
 
         mov     rdi, r13
@@ skipping 359 matching lines @@
         pop     rbx
         uncollect_args
         mov     rsp,rbp         ; rsp <- aligned rbp
         pop     rsp             ; rsp <- original rbp
         pop     rbp
         ret
 
 ; For some reason, the OS X linker does not honor the request to align the
 ; segment unless we do this.
         align   16