vrp bitfield miscompilation (WAS: [Regression] snd_emu10k1 doesn't work after GCC 4.2 upgrade)

From: Yuriy Tsibizov <Yuriy.Tsibizov_at_gfk.ru>
Date: Mon, 28 May 2007 10:22:03 +0400
 

> -----Original Message-----
> From: Yuriy Tsibizov 
> Sent: Sunday, May 27, 2007 1:42 AM
> To: Yuriy Tsibizov; kabaev_at_gmail.com
> Cc: current_at_freebsd.org
> Subject: Re: [Regression] snd_emu10k1 doesn't work after GCC 
> 4.2 upgrade
> 
> See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32100
> 
>
Use of following variables _can_ be affected by above miscompilation
(these are signed single-bit variables):

amd64/amd64/mp_machdep.c:	int	cpu_present:1;
amd64/amd64/mp_machdep.c:	int	cpu_bsp:1;
amd64/amd64/mp_machdep.c:	int	cpu_disabled:1;
dev/acpica/acpi_pci_link.c:	int	l_routed:1;
dev/acpica/acpi_pci_link.c:	int	l_isa_irq:1;
dev/sound/isa/ess.c:    	int type, duplex:1, newspeed:1;
dev/sound/pci/emu10k1.c:	int b16:1, stereo:1, busy:1, running:1,
ismaster:1;
dev/sound/pci/solo.c:    	int simplex_dir, type, duplex:1,
newspeed:1, dmasz[2];
dev/puc/puc.c:	int		p_hasintr:1;
dev/puc/puc_bfe.h:	int		sc_fastintr:1;
dev/puc/puc_bfe.h:	int		sc_leaving:1;
dev/puc/puc_bfe.h:	int		sc_polled:1;
dev/rp/rpvar.h:	int			rp_rts_iflow:1;
dev/rp/rpvar.h:	int			rp_disable_writes:1;
dev/rp/rpvar.h:	int			rp_cts:1;
dev/rp/rpvar.h:	int			rp_waiting:1;
dev/rp/rpvar.h:	int			rp_xmit_stopped:1;
dev/scc/scc_bfe.h:	int		m_attached:1;
dev/scc/scc_bfe.h:	int		m_fastintr:1;
dev/scc/scc_bfe.h:	int		m_hasintr:1;
dev/scc/scc_bfe.h:	int		m_probed:1;
dev/scc/scc_bfe.h:	int		m_sysdev:1;
dev/scc/scc_bfe.h:	int		ch_enabled:1;
dev/scc/scc_bfe.h:	int		ch_sysdev:1;
dev/scc/scc_bfe.h:	int		sc_fastintr:1;
dev/scc/scc_bfe.h:	int		sc_leaving:1;
dev/scc/scc_bfe.h:	int		sc_polled:1;
dev/uart/uart_bus.h:	int		sc_callout:1;	/* This UART is
opened for callout. */
dev/uart/uart_bus.h:	int		sc_fastintr:1;	/* This UART
uses fast interrupts. */
dev/uart/uart_bus.h:	int		sc_hwiflow:1;	/* This UART has
HW input flow ctl. */
dev/uart/uart_bus.h:	int		sc_hwoflow:1;	/* This UART has
HW output flow ctl. */
dev/uart/uart_bus.h:	int		sc_leaving:1;	/* This UART is
going away. */
dev/uart/uart_bus.h:	int		sc_opened:1;	/* This UART is
open for business. */
dev/uart/uart_bus.h:	int		sc_polled:1;	/* This UART has
no interrupts. */
dev/uart/uart_bus.h:	int		sc_txbusy:1;	/* This UART is
transmitting. */
fs/pseudofs/pseudofs_internal.h:	int		 pvd_dead:1;
geom/part/g_part.h:	int		gpe_created:1;	/* Entry is
newly created. */
geom/part/g_part.h:	int		gpe_deleted:1;	/* Entry has
been deleted. */
geom/part/g_part.h:	int		gpe_modified:1;	/* Entry has
been modified. */
geom/part/g_part.h:	int		gpt_isleaf:1;	/* Cannot be
sub-partitioned. */
geom/part/g_part.h:	int		gpt_created:1;	/* Newly
created. */
geom/part/g_part.h:	int		gpt_modified:1;	/* Table changes
have been made. */
geom/part/g_part.h:	int		gpt_opened:1;	/* Permissions
obtained. */
i386/i386/mp_machdep.c:	int	cpu_present:1;
i386/i386/mp_machdep.c:	int	cpu_bsp:1;
i386/i386/mp_machdep.c:	int	cpu_disabled:1;
i386/include/npx.h:	int	fp_sgn:1;	/* mantissa sign */
sparc64/pci/psycho.c:		int apb:1;
sparc64/pci/psycho.c:		int ppb:1;

I can't say that there _is_ a miscompilation related to all variables in
this list.

Should most of them (I'm not shure for fp_sign) be changed to unsigned
int? With (signed) int these flags have values of (-1;0), with unsigned
int they will use more obvious (0;1) values.


Yuriy.
Received on Mon May 28 2007 - 04:19:18 UTC

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