| .file "shr_Xsig.S" |
| /*---------------------------------------------------------------------------+ |
| | shr_Xsig.S | |
| | | |
| | 12 byte right shift function | |
| | | |
| | Copyright (C) 1992,1994,1995 | |
| | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | |
| | Australia. E-mail billm@jacobi.maths.monash.edu.au | |
| | | |
| | Call from C as: | |
| | void shr_Xsig(Xsig *arg, unsigned nr) | |
| | | |
| | Extended shift right function. | |
| | Fastest for small shifts. | |
| | Shifts the 12 byte quantity pointed to by the first arg (arg) | |
| | right by the number of bits specified by the second arg (nr). | |
| | | |
| +---------------------------------------------------------------------------*/ |
| |
| #include "fpu_emu.h" |
| |
| .text |
| ENTRY(shr_Xsig) |
| push %ebp |
| movl %esp,%ebp |
| pushl %esi |
| movl PARAM2,%ecx |
| movl PARAM1,%esi |
| cmpl $32,%ecx /* shrd only works for 0..31 bits */ |
| jnc L_more_than_31 |
| |
| /* less than 32 bits */ |
| pushl %ebx |
| movl (%esi),%eax /* lsl */ |
| movl 4(%esi),%ebx /* midl */ |
| movl 8(%esi),%edx /* msl */ |
| shrd %cl,%ebx,%eax |
| shrd %cl,%edx,%ebx |
| shr %cl,%edx |
| movl %eax,(%esi) |
| movl %ebx,4(%esi) |
| movl %edx,8(%esi) |
| popl %ebx |
| popl %esi |
| leave |
| ret |
| |
| L_more_than_31: |
| cmpl $64,%ecx |
| jnc L_more_than_63 |
| |
| subb $32,%cl |
| movl 4(%esi),%eax /* midl */ |
| movl 8(%esi),%edx /* msl */ |
| shrd %cl,%edx,%eax |
| shr %cl,%edx |
| movl %eax,(%esi) |
| movl %edx,4(%esi) |
| movl $0,8(%esi) |
| popl %esi |
| leave |
| ret |
| |
| L_more_than_63: |
| cmpl $96,%ecx |
| jnc L_more_than_95 |
| |
| subb $64,%cl |
| movl 8(%esi),%eax /* msl */ |
| shr %cl,%eax |
| xorl %edx,%edx |
| movl %eax,(%esi) |
| movl %edx,4(%esi) |
| movl %edx,8(%esi) |
| popl %esi |
| leave |
| ret |
| |
| L_more_than_95: |
| xorl %eax,%eax |
| movl %eax,(%esi) |
| movl %eax,4(%esi) |
| movl %eax,8(%esi) |
| popl %esi |
| leave |
| ret |
