[lkml]   [2003]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Runaway cron task on 2.5.63/4 bk?
Linus Torvalds <> wrote:
> On Tue, 11 Mar 2003, Andrew Morton wrote:
> >
> > gcc will generate 64bit * 64bit multiplies without resorting to
> > any library code
> However, gcc is unable to do-the-right-thing and generate 32x32->64
> multiplies, or 32x64->64 multiplies, even though those are both a _lot_
> faster than the full 64x64->64 case.

2.95.3 and 3.2.1 seem to do it right?

long a;
long b;
long long c;

void foo(void)
c = a * b;

.file "t.c"
.version "01.01"
.align 4
.globl foo
.type foo,@function
pushl %ebp
movl %esp,%ebp
movl a,%eax
imull b,%eax
movl %eax,c
movl %edx,c+4
movl %ebp,%esp
popl %ebp
.size foo,.Lfe1-foo
.comm a,4,4
.comm b,4,4
.comm c,8,4
.ident "GCC: (GNU) 2.95.3 20010315 (release)"

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:33    [W:0.110 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site