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From: Segher Boessenkool <segher@kernel.crashing.org>
To: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, anton@samba.org,
	Matt Brown <matthew.brown.dev@gmail.com>
Subject: Re: [PATCH 1/5] powerpc/lib/sstep: Add cmpb instruction emulation
Date: Thu, 13 Jul 2017 02:10:46 -0500	[thread overview]
Message-ID: <20170713071046.GA13471@gate.crashing.org> (raw)
In-Reply-To: <20170713064352.GY13471@gate.crashing.org>

On Thu, Jul 13, 2017 at 01:43:53AM -0500, Segher Boessenkool wrote:
> On Thu, Jul 13, 2017 at 01:51:30PM +1000, Andrew Donnellan wrote:
> > On 13/07/17 13:25, Matt Brown wrote:
> > >@@ -1049,6 +1066,13 @@ int analyse_instr(struct instruction_op *op, struct 
> > >pt_regs *regs,
> > > 			do_cmp_unsigned(regs, val, val2, rd >> 2);
> > > 			goto instr_done;
> > >
> > >+		case 19173952: /* cmpb */
> > 
> > This looks wrong and should never trigger, given that the switch 
> > statement is comparing against ((instr >> 1) & 0x3ff).
> > 
> > How did you get this value?
> 
> The correct number is 508, and 19173952 = 37744*508.  How to get
> 37744 is a mystery though :-)

Ah.  Take the binary representation of 508, and interpret that as if
it were octal :-)  Those pesky meddling leading zeroes!


Segher

  reply	other threads:[~2017-07-13  7:10 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-13  3:25 [PATCH 1/5] powerpc/lib/sstep: Add cmpb instruction emulation Matt Brown
2017-07-13  3:25 ` [PATCH 2/5] powerpc/lib/sstep: Add popcnt " Matt Brown
2017-07-13  3:25 ` [PATCH 3/5] powerpc/lib/sstep: Add bpermd " Matt Brown
2017-07-13  7:16   ` Gabriel Paubert
2017-07-13  7:28   ` Segher Boessenkool
2017-07-14  4:19     ` Matt Brown
2017-07-14 16:17       ` Segher Boessenkool
2017-07-13  3:25 ` [PATCH 4/5] powerpc/lib/sstep: Add prty " Matt Brown
2017-07-13  7:37   ` Segher Boessenkool
2017-07-14  0:46     ` Matt Brown
2017-07-14 19:02   ` kbuild test robot
2017-07-13  3:25 ` [PATCH 5/5] powerpc/lib/sstep: Add isel " Matt Brown
2017-07-13  7:47   ` Segher Boessenkool
2017-07-14  0:49     ` Matt Brown
2017-07-13  3:51 ` [PATCH 1/5] powerpc/lib/sstep: Add cmpb " Andrew Donnellan
2017-07-13  6:43   ` Segher Boessenkool
2017-07-13  7:10     ` Segher Boessenkool [this message]
2017-07-13  6:46 ` Segher Boessenkool

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