linux/include/asm-sparc
David S. Miller 405849610f [MATH-EMU]: Fix underflow exception reporting.
The underflow exception cases were wrong.

This is one weird area of ieee1754 handling in that the underflow
behavior changes based upon whether underflow is enabled in the trap
enable mask of the FPU control register.  As a specific case the Sparc
V9 manual gives us the following description:

--------------------
If UFM = 0:     Underflow occurs if a nonzero result is tiny and a
                loss of accuracy occurs.  Tininess may be detected
                before or after rounding.  Loss of accuracy may be
                either a denormalization loss or an inexact result.

If UFM = 1:     Underflow occurs if a nonzero result is tiny.
                Tininess may be detected before or after rounding.
--------------------

What this amounts to in the packing case is if we go subnormal,
we set underflow if any of the following are true:

1) rounding sets inexact
2) we ended up rounding back up to normal (this is the case where
   we set the exponent to 1 and set the fraction to zero), this
   should set inexact too
3) underflow is set in FPU control register trap-enable mask

The initially discovered example was "DBL_MIN / 16.0" which
incorrectly generated an underflow.  It should not, unless underflow
is set in the trap-enable mask of the FPU csr.

Another example, "0x0.0000000000001p-1022 / 16.0", should signal both
inexact and underflow.  The cpu implementations and ieee1754
literature is very clear about this.  This is case #2 above.

However, if underflow is set in the trap enable mask, only underflow
should be set and reported as a trap.  That is handled properly by the
prioritization logic in

arch/sparc{,64}/math-emu/math.c:record_exception().

Based upon a report and test case from Jakub Jelinek.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-16 22:59:49 -07:00
..
a.out.h arch: personality independent stack top 2007-07-19 10:04:45 -07:00
apc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
asi.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
asmmacro.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
atomic.h [SPARC]: Emulate cmpxchg like parisc 2007-05-29 02:51:13 -07:00
auxio.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
auxvec.h [PATCH] auxiliary vector cleanups 2005-09-07 16:57:21 -07:00
bitext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
bitops.h [SPARC]: Make bitops use same spinlocks as atomics. 2006-12-17 16:18:47 -08:00
bpp.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
bsderrno.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
btfixup.h [PATCH] fix the breakage in sparc headers 2005-10-05 07:33:42 -07:00
bug.h [PATCH] remove all kernel BUGs 2005-05-01 08:59:01 -07:00
bugs.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
byteorder.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cache.h [PATCH] Kill L1_CACHE_SHIFT_MAX 2006-01-08 20:13:39 -08:00
cacheflush.h [PATCH] Optimize D-cache alias handling on fork 2006-12-13 09:27:08 -08:00
checksum.h [SPARC32]: Fix over-optimization by GCC near ip_fast_csum. 2007-02-01 20:24:35 -08:00
clock.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
contregs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cpudata.h [SPARC]: Try to start getting SMP back into shape. 2006-03-23 22:36:19 -08:00
cputime.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
current.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cypress.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
delay.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
device.h [SPARC64]: Fix conflicts in SBUS/PCI/EBUS/ISA DMA handling. 2007-07-30 00:27:34 -07:00
div64.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dma-mapping.h [PATCH] sparc: have dma-mapping.h include generic/dma-mapping-broken in non-PCI case 2007-03-14 15:27:49 -07:00
dma.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
ebus.h [SPARC]: Port of_device layer and make ebus use it. 2006-06-23 23:15:47 -07:00
ecc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
eeprom.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
elf.h [SPARC]: Clean up asm-sparc/elf.h pollution in userspace. 2006-10-20 00:29:33 -07:00
emergency-restart.h [PATCH] Add emergency_restart() 2005-07-26 14:35:41 -07:00
errno.h [PATCH] add EOWNERDEAD and ENOTRECOVERABLE version 2 2005-05-01 08:59:06 -07:00
fb.h [SPARC]: Implement fb_is_primary_device(). 2007-07-20 17:15:09 -07:00
fbio.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fcntl.h [SPARC32]: Fix build. 2007-08-04 21:17:18 -07:00
fixmap.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
floppy.h [SPARC32]: Fix modular build of floppy driver. 2007-08-03 14:08:42 -07:00
futex.h [PATCH] consolidate asm/futex.h 2006-01-08 20:13:39 -08:00
hardirq.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
head.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
highmem.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
hw_irq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ide.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
idprom.h [SPARC]: Clean up idprom header files. 2006-03-20 01:12:08 -08:00
io-unit.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
io.h [PATCH] add missing io...._rep() on sparc32 2007-02-11 11:18:07 -08:00
ioctl.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctls.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
iommu.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
ipc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ipcbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
irq_regs.h [PATCH] sparc32 pt_regs fixes 2006-10-08 12:32:35 -07:00
irq.h [SPARC32]: Fix modular build of floppy driver. 2007-08-03 14:08:42 -07:00
jsflash.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Kbuild Fix exported headers for SPARC, SPARC64 2006-09-21 08:48:27 +01:00
kdebug.h [SPARC32]: Fix sparc32 kdebug changes. 2007-05-14 03:22:08 -07:00
kgdb.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kmap_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
linkage.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
local.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machines.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mbus.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
mc146818rtc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
memreg.h [PATCH] sun4c_memerr_reg __iomem annotations 2005-12-15 10:01:29 -08:00
mman.h [PATCH] IA64,sparc: local DoS with corrupted ELFs 2006-09-08 08:40:46 -07:00
mmu_context.h [PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destruction 2007-05-02 19:27:14 +02:00
mmu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
module.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mostek.h [SPARC]: sparc64 gcc-4.2.0 20070317 -Werror failure 2007-03-27 01:13:55 -07:00
mpmbox.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msgbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msi.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
mutex.h [PATCH] mutex subsystem, add default include/asm-*/mutex.h files 2006-01-09 15:59:19 -08:00
mxcc.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
namei.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
obio.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
of_device.h Create linux/of_platorm.h 2007-07-20 14:25:22 +10:00
of_platform.h Create linux/of_platorm.h 2007-07-20 14:25:22 +10:00
openprom.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
openpromio.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
oplib.h [SPARC]: Fix serial console device detection. 2007-07-20 16:59:26 -07:00
page.h Fix exported headers for SPARC, SPARC64 2006-09-21 08:48:27 +01:00
param.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pbm.h [SPARC]: Port sparc64 in-kernel device tree code to sparc32. 2006-06-23 23:15:45 -07:00
pci.h PCI: remove pci_dac_dma_... APIs 2007-07-11 16:02:11 -07:00
pcic.h [PATCH] fix iomem annotations in sparc32 pcic code 2005-12-15 10:01:28 -08:00
pconf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
percpu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfctr.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgalloc.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
pgtable.h [SPARC32]: Make PAGE_SHARED a read-mostly variable. 2007-07-21 19:20:34 -07:00
pgtsrmmu.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
pgtsun4.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgtsun4c.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
poll.h Consolidate asm/poll.h 2007-05-11 08:29:34 -07:00
posix_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
processor.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
prom.h [SPARC]: Centralize find_in_proplist() instead of duplicating N times. 2007-08-07 18:46:36 -07:00
psr.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
ptrace.h [PATCH] consolidate sys_ptrace() 2005-11-07 07:53:42 -08:00
reg.h fix file specification in comments 2006-10-03 23:01:26 +02:00
resource.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ross.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rtc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sbi.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
sbus.h [SPARC32]: Remove iommu from struct sbus_bus and use archdata like sparc64. 2007-08-10 15:52:06 -07:00
scatterlist.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sections.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
semaphore.h [PATCH] semaphore: Remove __MUTEX_INITIALIZER() 2005-10-30 17:37:27 -08:00
sembuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
setup.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sfp-machine.h [MATH-EMU]: Fix underflow exception reporting. 2007-08-16 22:59:49 -07:00
shmbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
shmparam.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sigcontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
siginfo.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal.h [SPARC]: Fix SA_STATIC_ALLOC value. 2006-07-24 22:34:00 -07:00
smp.h Remove hardcoding of hard_smp_processor_id on UP systems 2007-05-09 12:30:48 -07:00
smpprim.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
socket.h [NET]: Adding SO_TIMESTAMPNS / SCM_TIMESTAMPNS support 2007-04-25 22:24:21 -07:00
sockios.h [NET]: Introduce SIOCGSTAMPNS ioctl to get timestamps with nanosec resolution 2007-04-25 22:24:04 -07:00
solerrno.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
spinlock_types.h [PATCH] spinlock consolidation 2005-09-10 10:06:21 -07:00
spinlock.h [PATCH] sparc32 rwlock fix 2006-10-08 12:32:35 -07:00
stat.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
statfs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
string.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sun4paddr.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sun4prom.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sunbpp.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
svr4.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
swift.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sysen.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
system.h [PATCH] sched: sched_cacheflush is now unused 2007-07-19 21:28:35 +02:00
termbits.h [PATCH] tty: preparatory structures for termios revamp 2006-12-08 08:28:56 -08:00
termios.h [PATCH] consolidate line discipline number definitions 2007-02-11 10:51:26 -08:00
thread_info.h [SPARC]: Add support for *at(), ppoll, and pselect syscalls. 2006-01-19 02:42:49 -08:00
timer.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
timex.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tlb.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tlbflush.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
topology.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
traps.h [SPARC]: "extern inline" doesn't make much sense. 2005-10-03 17:37:02 -07:00
tsunami.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
turbosparc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
types.h [PATCH] sab: consolidate kmem_bufctl_t 2005-09-05 00:05:48 -07:00
uaccess.h [SPARC]: Kill off these __put_user_ret things. 2006-03-20 01:13:15 -08:00
unaligned.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
unistd.h [SPARC]: Add sys_fallocate() entries. 2007-07-19 21:26:47 -07:00
user.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vac-ops.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
vaddrs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vfc_ioctls.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vga.h [PATCH] sparc32 vga support 2006-04-11 06:18:54 -07:00
viking.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
winmacro.h Don't include linux/config.h from anywhere else in include/ 2006-04-26 12:56:16 +01:00
xor.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00