On 08/30/2011 11:58 AM, Duncan Sands wrote:
Hi Zachary, this patch can cause a compile failure if the compiler
chooses to
use a memory location for mul_frac rather than a register (as allowed
by the
"m" in the constraints):
pvclock.s:229: Error: no instruction mnemonic suffix given and no
register operands; can't size instruction
In this example the assembler is:
#APP
mul -48(%rbp) ; shrd $32, %rdx, %rax
#NO_APP
A simple solution is to use mulq, as in the following patch:
Signed-off-by: Duncan Sands <baldrick@xxxxxxx>
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -44,7 +44,7 @@ static inline u64 pvclock_scale_delta(u64 delta, u32
mul_frac, int shift)
: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2"
(mul_frac) );
#elif defined(__x86_64__)
__asm__ (
- "mul %[mul_frac] ; shrd $32, %[hi], %[lo]"
+ "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
: [lo]"=a"(product),
[hi]"=d"(tmp)
: "0"(delta),
Thanks, applied.
--
error compiling committee.c: too many arguments to function
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
