* finding floating point use in the kernel
@ 2004-05-12 18:02 richard.coe
2004-05-12 18:29 ` Chris Wedgwood
0 siblings, 1 reply; 2+ messages in thread
From: richard.coe @ 2004-05-12 18:02 UTC (permalink / raw)
To: linux-kernel
While trying to track down a problem with some floating point calculations,
I wrote the following script. Perhaps someone can add it to the
kernel Makefile to run when the Platform is I386.
#!/bin/bash
# probably runs faster in perl
# d[89a-f] are floating point insns on I386
find . -type f | egrep '\.o$' | while read fn ; do
objdump -d $fn | egrep ':.d[89a-f]' > /tmp/od1.$$
if [ -s "/tmp/od1.$$" ]; then
echo "$fn"
cat /tmp/od1.$$
rm /tmp/od1.$$
fi
done
On my 2.4.22 kernel, it found the following:
./fs/jbd/transaction.o
5f1: db 01 fildl (%ecx)
664: da 01 fiaddl (%ecx)
ae0: d9 02 flds (%edx)
14af: de 04 10 fiadd (%eax,%edx,1)
./fs/jbd/commit.o
7eb: d9 02 flds (%edx)
f64: dd 00 fldl (%eax)
./fs/jbd/journal.o
e30: da 03 fiaddl (%ebx)
./fs/jbd/jbd.o
5f1: db 01 fildl (%ecx)
664: da 01 fiaddl (%ecx)
ae0: d9 02 flds (%edx)
14af: de 04 10 fiadd (%eax,%edx,1)
2a2b: d9 02 flds (%edx)
31a4: dd 00 fldl (%eax)
467a: df fe (bad)
5eb0: da 03 fiaddl (%ebx)
./fs/nfs/pagelist.o
1ce: dd 0f fisttpll (%edi)
./fs/nfs/write.o
1704: db fd (bad)
./fs/nfs/nfs.o
9674: db fd (bad)
./fs/udf/udf.o
406d: db 74 06 83 (bad) 0xffffff83(%esi,%eax,1)
./fs/sysv/dir.o
530: dd 00 fldl (%eax)
./fs/sysv/sysv.o
2c20: dd 00 fldl (%eax)
./fs/fs.o
4d62: d8 89 04 24 75 e8 fmuls 0xe8752404(%ecx)
2e170: db 10 fistl (%eax)
2fdfa: db 10 fistl (%eax)
307d1: db 01 fildl (%ecx)
30844: da 01 fiaddl (%ecx)
30cc0: d9 02 flds (%edx)
32c0b: d9 02 flds (%edx)
33384: dd 00 fldl (%eax)
36090: da 03 fiaddl (%ebx)
46b8e: dd 0f fisttpll (%edi)
./mm/mmap.o
b77: de 02 fiadd (%edx)
./mm/bootmem.o
20e: db c7 fcmovnb %st(7),%st
363: d9 73 0a fnstenv 0xa(%ebx)
./mm/page_alloc.o
3b5: d9 00 flds (%eax)
./mm/mm.o
2747: de 02 fiadd (%edx)
b4e5: d9 00 flds (%eax)
c16d: d9 89 f6 53 8b 5c (bad) 0x5c8b53f6(%ecx)
406: d9 72 e7 fnstenv 0xffffffe7(%edx)
45e: db c7 fcmovnb %st(7),%st
5b3: d9 73 0a fnstenv 0xa(%ebx)
./ipc/ipc.o
36f9: da 8d b6 00 00 00 fimull 0xb6(%ebp)
./net/core/skbuff.o
d26: db 02 fildl (%edx)
./net/core/dev.o
859: d8 03 fadds (%ebx)
88b: df 03 fild (%ebx)
8c2: dd 03 fldl (%ebx)
./net/core/core.o
24a6: db 02 fildl (%edx)
58b9: d8 03 fadds (%ebx)
58eb: df 03 fild (%ebx)
5922: dd 03 fldl (%ebx)
./net/ipv4/netfilter/arp_tables.o
52e: db 00
./net/ipv4/ipv4.o
14693: d9 89 d0 d3 f8 e9 (bad) 0xe9f8d3d0(%ecx)
./net/network.o
4236: db 02 fildl (%edx)
7649: d8 03 fadds (%ebx)
767b: df 03 fild (%ebx)
76b2: dd 03 fldl (%ebx)
284c3: d9 89 d0 d3 f8 e9 (bad) 0xe9f8d3d0(%ecx)
2d385: dd 02 00
2d3b0: d8 02 00
./arch/i386/boot/bbootsect.o
197: df c3 ffreep %st(3)
./arch/i386/boot/bsetup.o
501: db 57 72 fistl 0x72(%edi)
5a6: db cd fcmovne %st(5),%st
668: db 31 (bad) (%ecx)
693: db 31 (bad) (%ecx)
b51: d8 05 b0 78 e8 08 fadds 0x8e878b0
ccf: df ad 83 f8 fd 74 fildll 0x74fdf883(%ebp)
f1d: db 01 fildl (%ecx)
./arch/i386/kernel/i387.o
50: db e3 fninit
77: db e2 fnclex
90: dd b2 b0 02 00 00 fnsave 0x2b0(%edx)
c5: db e2 fnclex
e0: dd b1 b0 02 00 00 fnsave 0x2b0(%ecx)
120: dd a2 b0 02 00 00 frstor 0x2b0(%edx)
./arch/i386/kernel/kernel.o
7710: db e3 fninit
7737: db e2 fnclex
7750: dd b2 b0 02 00 00 fnsave 0x2b0(%edx)
7785: db e2 fnclex
77a0: dd b1 b0 02 00 00 fnsave 0x2b0(%ecx)
77e0: dd a2 b0 02 00 00 frstor 0x2b0(%edx)
./arch/i386/kernel/head.o
19d: db e3 fninit
1b7: db e4 fnsetpm(287 only)
./init/main.o
65: db e3 fninit
67: dd 05 20 00 00 00 fldl 0x20
6d: dc 35 28 00 00 00 fdivl 0x28
73: dc 0d 28 00 00 00 fmull 0x28
79: dd 05 20 00 00 00 fldl 0x20
7f: de e1 fsubp %st,%st(1)
81: db 1d 70 00 00 00 fistpl 0x70
./drivers/ide/pci/siimage.o
272: db 00 fildl (%eax)
./drivers/ide/pci/idedriver-pci.o
9ff2: db 00 fildl (%eax)
./drivers/ide/idedriver.o
9ff2: db 00 fildl (%eax)
./drivers/ide/ide-tape.o
d42: de 08 fimul (%eax)
./drivers/net/wireless/orinoco.o
30b2: de 09 fimul (%ecx)
./drivers/net/wireless/wireless_net.o
30b2: de 09 fimul (%ecx)
./drivers/net/bonding/bond_main.o
1dd: d8 5b c3 fcomps 0xffffffc3(%ebx)
./drivers/net/bonding/bonding.o
1dd: d8 5b c3 fcomps 0xffffffc3(%ebx)
./drivers/net/natsemi.o
2e39: db fe (bad)
./drivers/net/tg3.o
21b6: de 06 fiadd (%esi)
21c3: da 06 fiaddl (%esi)
./drivers/net/amd8111e.o
1ee3: df 2c 24 fildll (%esp,1)
1ee9: d9 7c 24 0a fnstcw 0xa(%esp,1)
1ef9: dc 05 00 00 00 00 faddl 0x0
1eff: d9 6c 24 08 fldcw 0x8(%esp,1)
1f03: df 3c 24 fistpll (%esp,1)
1f06: d9 6c 24 0a fldcw 0xa(%esp,1)
1fe5: df 2c 24 fildll (%esp,1)
1feb: d9 7c 24 0a fnstcw 0xa(%esp,1)
1ffb: dc 05 08 00 00 00 faddl 0x8
2001: d9 6c 24 08 fldcw 0x8(%esp,1)
2005: df 3c 24 fistpll (%esp,1)
2008: d9 6c 24 0a fldcw 0xa(%esp,1)
2369: df 2c 24 fildll (%esp,1)
236f: d9 7c 24 12 fnstcw 0x12(%esp,1)
237f: dc 05 10 00 00 00 faddl 0x10
2385: d9 6c 24 10 fldcw 0x10(%esp,1)
2389: df 7c 24 08 fistpll 0x8(%esp,1)
238d: d9 6c 24 12 fldcw 0x12(%esp,1)
./drivers/usb/host/uhci.o
1bd8: df
./drivers/usb/host/usb-uhci.o
1089: df
./drivers/block/ll_rw_blk.o
5d9: d9 01 flds (%ecx)
5e0: df 0f fisttp (%edi)
./drivers/block/block.o
5d9: d9 01 flds (%ecx)
5e0: df 0f fisttp (%edi)
3a01: dc 00 00
5f68: db 00 00
./drivers/sound/via82cxxx_audio.o
3a8: db 02 fildl (%edx)
./drivers/video/sis/sis_main.o
1c0c: df 2c 24 fildll (%esp,1)
1c16: df 2c 24 fildll (%esp,1)
1c19: d9 c9 fxch %st(1)
1c22: dc 3d 00 00 00 00 fdivrl 0x0
1c28: de f1 fdivp %st,%st(1)
1c2a: df 2c 24 fildll (%esp,1)
1c30: d9 7c 24 12 fnstcw 0x12(%esp,1)
1c34: de f9 fdivrp %st,%st(1)
1c36: d8 c0 fadd %st(0),%st
1c44: dc 05 08 00 00 00 faddl 0x8
1c4a: d9 6c 24 10 fldcw 0x10(%esp,1)
1c4e: df 7c 24 08 fistpll 0x8(%esp,1)
1c52: d9 6c 24 12 fldcw 0x12(%esp,1)
26c6: df 2c 24 fildll (%esp,1)
26d7: da 0c 24 fimull (%esp,1)
26e7: dc 0d 10 00 00 00 fmull 0x10
26ed: da 0c 24 fimull (%esp,1)
26f3: d9 7c 24 32 fnstcw 0x32(%esp,1)
2703: dc 3d 18 00 00 00 fdivrl 0x18
2709: d9 6c 24 30 fldcw 0x30(%esp,1)
270d: df 7c 24 28 fistpll 0x28(%esp,1)
2711: d9 6c 24 32 fldcw 0x32(%esp,1)
./drivers/video/sis/sisfb.o
1c0c: df 2c 24 fildll (%esp,1)
1c16: df 2c 24 fildll (%esp,1)
1c19: d9 c9 fxch %st(1)
1c22: dc 3d 00 00 00 00 fdivrl 0x0
1c28: de f1 fdivp %st,%st(1)
1c2a: df 2c 24 fildll (%esp,1)
1c30: d9 7c 24 12 fnstcw 0x12(%esp,1)
1c34: de f9 fdivrp %st,%st(1)
1c36: d8 c0 fadd %st(0),%st
1c44: dc 05 08 00 00 00 faddl 0x8
1c4a: d9 6c 24 10 fldcw 0x10(%esp,1)
1c4e: df 7c 24 08 fistpll 0x8(%esp,1)
1c52: d9 6c 24 12 fldcw 0x12(%esp,1)
26c6: df 2c 24 fildll (%esp,1)
26d7: da 0c 24 fimull (%esp,1)
26e7: dc 0d 10 00 00 00 fmull 0x10
26ed: da 0c 24 fimull (%esp,1)
26f3: d9 7c 24 32 fnstcw 0x32(%esp,1)
2703: dc 3d 18 00 00 00 fdivrl 0x18
2709: d9 6c 24 30 fldcw 0x30(%esp,1)
270d: df 7c 24 28 fistpll 0x28(%esp,1)
2711: d9 6c 24 32 fldcw 0x32(%esp,1)
./drivers/video/matrox/matroxfb_DAC1064.o
e57: df ff ff
./drivers/video/matrox/matroxfb_misc.o
15ab: d8 03 00
15b5: d8 03 00
./drivers/message/i2o/i2o_core.o
20b2: de
./drivers/ieee1394/ieee1394_transactions.o
491: de 8d b4 26 00 00 fimul 0x26b4(%ebp)
./drivers/ieee1394/dma.o
489: db 8b 44 24 1c 39 fisttpl 0x391c2444(%ebx)
./drivers/ieee1394/ieee1394.o
20c1: de 8d b4 26 00 00 fimul 0x26b4(%ebp)
7809: db 8b 44 24 1c 39 fisttpl 0x391c2444(%ebx)
--
Rich Coe richard.coe@med.ge.com
General Electric Healthcare
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: finding floating point use in the kernel
2004-05-12 18:02 finding floating point use in the kernel richard.coe
@ 2004-05-12 18:29 ` Chris Wedgwood
0 siblings, 0 replies; 2+ messages in thread
From: Chris Wedgwood @ 2004-05-12 18:29 UTC (permalink / raw)
To: richard.coe; +Cc: linux-kernel
On Wed, May 12, 2004 at 01:02:45PM -0500, richard.coe@med.ge.com wrote:
> While trying to track down a problem with some floating point
> calculations, I wrote the following script. Perhaps someone can add
> it to the kernel Makefile to run when the Platform is I386.
As was just pointed out to me, this finds instructions which are never
executed (they are just part of alignment/padding) and decodes them
resulting in false positives.
Christoph pointed out -mm has -msoft-float which I think should be
sufficient to catch anything bad going on by accident.
--cw
^ permalink raw reply [flat|nested] 2+ messages in thread
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2004-05-12 18:29 ` Chris Wedgwood
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