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

simd/jiss2flt-64.asm

 ;
 ; jiss2flt-64.asm - floating-point IDCT (64-bit SSE & SSE2)
 ;
 ; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
 ; Copyright 2009 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 308 matching lines @@
         prefetchnta [rsi + (DCTSIZE2-8)*SIZEOF_JCOEF + 0*32]
         prefetchnta [rsi + (DCTSIZE2-8)*SIZEOF_JCOEF + 1*32]
         prefetchnta [rsi + (DCTSIZE2-8)*SIZEOF_JCOEF + 2*32]
         prefetchnta [rsi + (DCTSIZE2-8)*SIZEOF_JCOEF + 3*32]
 
         ; ---- Pass 2: process rows from work array, store into output array.
 
         mov     rax, [original_rbp]
         lea     rsi, [workspace]                        ; FAST_FLOAT * wsptr
         mov     rdi, r12        ; (JSAMPROW *)
-        mov     rax, r13
+        mov     eax, r13d
         mov     rcx, DCTSIZE/4                          ; ctr
 .rowloop:
 
         ; -- Even part
 
         movaps  xmm0, XMMWORD [XMMBLOCK(0,0,rsi,SIZEOF_FAST_FLOAT)]
         movaps  xmm1, XMMWORD [XMMBLOCK(2,0,rsi,SIZEOF_FAST_FLOAT)]
         movaps  xmm2, XMMWORD [XMMBLOCK(4,0,rsi,SIZEOF_FAST_FLOAT)]
         movaps  xmm3, XMMWORD [XMMBLOCK(6,0,rsi,SIZEOF_FAST_FLOAT)]
 
@@ skipping 134 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