svn commit: r314087 - head/sys/x86/x86

[Konstantin Belousov]

On Thu, Feb 23, 2017 at 06:33:43AM +1100, Bruce Evans wrote:
> On Wed, 22 Feb 2017, Konstantin Belousov wrote:
> 
> > Log:
> >  More fixes for regression in r313898 on i386.
> >  Use long long constants where needed.
> 
> The long long abomination is never needed, and is always a style bug.
I never saw any explanation behind this claim.  Esp. the first part
of it, WRT 'never needed'.

> I don't like using explicit long constants either.  Here the number of bits
> in the register is fixed by the hardware at 64.  The number of bits in a
> long on amd64 and a long on i386 is only fixed by ABI because the ABI is
> broken for historical reasons.
I really cannot make any sense of this statement.

>  Only very MD code can safely assume the
> size of long and long long.  This code was MD enough before it was merged,
> but now it shouldn't use long since that varies between amd64 and i386,
> and it shouldn't use long long since that is a style bug.

Well, I do not see anything wrong with long long, at least until
explained.

Anyway, below is the patch to use uint64_t cast in important place,
and removal of LL suffix in unimportant expression.

diff --git a/sys/x86/x86/x86_mem.c b/sys/x86/x86/x86_mem.c
index d639224f840..8bc4d3917a0 100644
--- a/sys/x86/x86/x86_mem.c
+++ b/sys/x86/x86/x86_mem.c
@@ -260,7 +260,7 @@ x86_mrfetch(struct mem_range_softc *sc)
 
 		/* Compute the range from the mask. Ick. */
 		mrd->mr_len = (~(msrv & mtrr_physmask) &
-		    (mtrr_physmask | 0xfffLL)) + 1;
+		    (mtrr_physmask | 0xfff)) + 1;
 		if (!mrvalid(mrd->mr_base, mrd->mr_len))
 			mrd->mr_flags |= MDF_BOGUS;
 
@@ -638,7 +638,8 @@ x86_mrinit(struct mem_range_softc *sc)
 	 * Determine the size of the PhysMask and PhysBase fields in
 	 * the variable range MTRRs.
 	 */
-	mtrr_physmask = (((uint64_t)1 << cpu_maxphyaddr) - 1) & ~0xfffULL;
+	mtrr_physmask = (((uint64_t)1 << cpu_maxphyaddr) - 1) &
+	    ~(uint64_t)0xfff;
 
 	/* If fixed MTRRs supported and enabled. */
 	if ((mtrrcap & MTRR_CAP_FIXED) && (mtrrdef & MTRR_DEF_FIXED_ENABLE)) {