> > Meanwhile, try piping objdump of a "-mmad" kernel
> > through "grep -i mad". I'd be stunned if a single MADD
> > turned up. If it gains nothing, but breaks builds, then
> > for heaven's sake banish -mmad from the kernel
> > makefiles!
>
> I managed to compile a 2.4.2 kernel with our bleeding edge toolchain. I
> had to get rid of the -mmad from the Makefile though. The kernel boots
> and runs and I ran Bonnie over NFS as well as on an IDE hard disk. I
> tried some other tests as well, and they all passed.
>
> Without the -mmad flag, I see the following mad instructions below. No
> "madd" though, just madd.s, madd16, mad, etc. So, can we get rid of this
> flag in the Makefile?
"MAD" is a synonym for "MADD", but it looks as if this was
a grep of the output of "objdump --diassemble-all". There
can't possibly be that many usefull floating point MADDs
in the kernel, and the actual bytes of the instructions look
suspiciously like ASCII strings. Likewise, "MADD16" and
"DMADD16" are R4100 instructions with a different opcode
and semantics from the Nevada/MIPS32 MADD. And of
course instructions like "mad $zero,$zero" aren't likely to
be real code. It's pretty obvious from context, but you
should really confirm that address 0x802c07f4 is data
before we confirm that *no* MAD/MADDS are being
generated in the kernel.
It is certainly conceivable that MADDs in some form
could be used in the kernel. Specifically, it would not
surprise me in the least to see them used in a software
modem on a VrLinux platform. But those modules can
and should be handled seperately (and are probably
written in assembler anyway). There's not need for
-mmad in the general set of flags.
Kevin K.
>
> 0000000080132690 <sys_madvise>:
> 801326dc: 1080fffc beqz $a0,801326d0 <sys_madvise+40>
> 801326e4: 04810004 bgez $a0,801326f8 <sys_madvise+68>
> 801326f8: 5440002e bnezl $v0,801327b4 <sys_madvise+124>
> 80132714: 54400027 bnezl $v0,801327b4 <sys_madvise+124>
> 8013271c: 12510024 beq $s2,$s1,801327b0
> <sys_madvise+120>
> 80132734: 1200001e beqz $s0,801327b0 <sys_madvise+120>
> 80132744: 10400003 beqz $v0,80132754 <sys_madvise+c4>
> 80132758: 1440000c bnez $v0,8013278c <sys_madvise+fc>
> 80132764: 10400007 beqz $v0,80132784 <sys_madvise+f4>
> 80132770: 0c04c988 jal 80132620 <madvise_vma>
> 8013277c: 5660000d bnezl $s3,801327b4 <sys_madvise+124>
> 80132784: 0804c9ec j 801327b0 <sys_madvise+120>
> 80132790: 0c04c988 jal 80132620 <madvise_vma>
> 8013279c: 56600005 bnezl $s3,801327b4 <sys_madvise+124>
> 801327a8: 0804c9cd j 80132734 <sys_madvise+a4>
> 801327c8: 1080fffc beqz $a0,801327bc <sys_madvise+12c>
> 801327d0: 1c800004 bgtz $a0,801327e4 <sys_madvise+154>
> 80250590: 4d4d2030 nmadd.s $f0,$f10,$f4,$f13
> 80250a84: 4f4e2820 madd.s $f0,$f26,$f5,$f14
> 802517bc: 00000029 dmadd16 $zero,$zero
> 80253c94: 00000029 dmadd16 $zero,$zero
> 802555a4: 00000029 dmadd16 $zero,$zero
> 80256178: 00000029 dmadd16 $zero,$zero
> 80259804: 4d445b20 madd.s $f12,$f10,$f11,$f4
> 80259810: 4d445b20 madd.s $f12,$f10,$f11,$f4
> 8025981c: 4d445b20 madd.s $f12,$f10,$f11,$f4
> 8025aa34: 00000029 dmadd16 $zero,$zero
> 8025bbf0: 4c257830 nmadd.s $f0,$f1,$f15,$f5
> 802618a8: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 80262018: 4e203a70 nmadd.s $f9,$f17,$f7,$f0
> 802625c4: 4c554e20 madd.s $f24,$f2,$f9,$f21
> 80262700: 4c554e20 madd.s $f24,$f2,$f9,$f21
> 80264d5c: 4c545220 madd.s $f8,$f2,$f10,$f20
> 80264d64: 00000029 dmadd16 $zero,$zero
> 80265148: 4e203d21 madd.d $f20,$f17,$f7,$f0
> 80265194: 4e203d21 madd.d $f20,$f17,$f7,$f0
> 8026534c: 00000029 dmadd16 $zero,$zero
> 80265b50: 4f495020 madd.s $f0,$f26,$f10,$f9
> 80265f70: 4c554e20 madd.s $f24,$f2,$f9,$f21
> 80266294: 4e554c20 madd.s $f16,$f18,$f9,$f21
> 802670bc: 4c4c4120 madd.s $f4,$f2,$f8,$f12
> 80267690: 4d207361 madd.d $f13,$f9,$f14,$f0
> 80267f5c: 00000029 dmadd16 $zero,$zero
> 80268314: 00000029 dmadd16 $zero,$zero
> 80268abc: 00000029 dmadd16 $zero,$zero
> 80269cd4: 4d435020 madd.s $f0,$f10,$f10,$f3
> 8026a504: 00000029 dmadd16 $zero,$zero
> 8026df88: 4c4c5020 madd.s $f0,$f2,$f10,$f12
> 8026e01c: 4c502070 nmadd.s $f1,$f2,$f4,$f16
> 8026f6bc: 4c622020 madd.s $f0,$f3,$f4,$f2
> 8026f71c: 4e622020 madd.s $f0,$f19,$f4,$f2
> 8026f944: 4c622020 madd.s $f0,$f3,$f4,$f2
> 8026f9f0: 4d772020 madd.s $f0,$f11,$f4,$f23
> 802702f8: 4d203231 nmadd.d $f8,$f9,$f6,$f0
> 80273830: 00000029 dmadd16 $zero,$zero
> 80276a24: 4f6d7361 madd.d $f13,$f27,$f14,$f13
> 80277498: 4e203d21 madd.d $f20,$f17,$f7,$f0
> 80279c10: 4d202020 madd.s $f0,$f9,$f4,$f0
> 80279ea4: 4d434920 madd.s $f4,$f10,$f9,$f3
> 8027c588: 4f494520 madd.s $f20,$f26,$f8,$f9
> 80280048: 4d642520 madd.s $f20,$f11,$f4,$f4
> 802802c8: 4d4f5220 madd.s $f8,$f10,$f10,$f15
> 802a0e00: 4e414d20 madd.s $f20,$f18,$f9,$f1
> 802a2988: 4c4f5720 madd.s $f28,$f2,$f10,$f15
> 802a2a30: 00000029 dmadd16 $zero,$zero
> 802a2c14: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802a336c: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802a39e4: 00000029 dmadd16 $zero,$zero
> 802a3a00: 00000029 dmadd16 $zero,$zero
> 802a3a1c: 00000029 dmadd16 $zero,$zero
> 802a3a70: 00000029 dmadd16 $zero,$zero
> 802a3ac8: 00000029 dmadd16 $zero,$zero
> 802a3ad0: 4d353531 nmadd.d $f20,$f9,$f6,$f21
> 802a3b3c: 00000029 dmadd16 $zero,$zero
> 802a427c: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802a50bc: 4d4f4320 madd.s $f12,$f10,$f8,$f15
> 802a5504: 4e414c20 madd.s $f16,$f18,$f9,$f1
> 802a57ec: 4c2e6920 madd.s $f4,$f1,$f13,$f14
> 802a5f18: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802a6378: 4d544120 madd.s $f4,$f10,$f8,$f20
> 802a63b4: 4d207161 madd.d $f5,$f9,$f14,$f0
> 802a6d5c: 00000029 dmadd16 $zero,$zero
> 802a6ea8: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802a6ebc: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802a73c0: 4e414c20 madd.s $f16,$f18,$f9,$f1
> 802a74cc: 4e414c20 madd.s $f16,$f18,$f9,$f1
> 802a75a0: 4f505420 madd.s $f16,$f26,$f10,$f16
> 802a7994: 4d502031 nmadd.d $f0,$f10,$f4,$f16
> 802a7ac0: 4e414c20 madd.s $f16,$f18,$f9,$f1
> 802a7b54: 4e206870 nmadd.s $f1,$f17,$f13,$f0
> 802a7e8c: 4d502820 madd.s $f0,$f10,$f5,$f16
> 802a7f84: 4e5b2061 madd.d $f1,$f18,$f4,$f27
> 802a7f90: 4e5b2061 madd.d $f1,$f18,$f4,$f27
> 802a7f9c: 4e5b2061 madd.d $f1,$f18,$f4,$f27
> 802a7fa8: 4e5b2061 madd.d $f1,$f18,$f4,$f27
> 802a8068: 00000029 dmadd16 $zero,$zero
> 802a8290: 4d5b2030 nmadd.s $f0,$f10,$f4,$f27
> 802a8c94: 4f525020 madd.s $f0,$f26,$f10,$f18
> 802a9088: 4e207370 nmadd.s $f13,$f17,$f14,$f0
> 802a94ec: 4d544120 madd.s $f4,$f10,$f8,$f20
> 802a962c: 4d544120 madd.s $f4,$f10,$f8,$f20
> 802a9c10: 00000029 dmadd16 $zero,$zero
> 802a9d64: 00000029 dmadd16 $zero,$zero
> 802a9d80: 00000029 dmadd16 $zero,$zero
> 802a9e2c: 00000029 dmadd16 $zero,$zero
> 802ab81c: 00000029 dmadd16 $zero,$zero
> 802ac17c: 00000029 dmadd16 $zero,$zero
> 802ac65c: 4d207861 madd.d $f1,$f9,$f15,$f0
> 802ac740: 4d207861 madd.d $f1,$f9,$f15,$f0
> 802ac79c: 4c525320 madd.s $f12,$f2,$f10,$f18
> 802ad3e4: 4e206c61 madd.d $f17,$f17,$f13,$f0
> 802ad954: 4d202d20 madd.s $f20,$f9,$f5,$f0
> 802ae994: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802af200: 4e415720 madd.s $f28,$f18,$f10,$f1
> 802b10cc: 4e414320 madd.s $f12,$f18,$f8,$f1
> 802b167c: 4e454420 madd.s $f16,$f18,$f8,$f5
> 802b1690: 4c554d20 madd.s $f20,$f2,$f9,$f21
> 802b1d88: 4d4f4320 madd.s $f12,$f10,$f8,$f15
> 802b1df0: 00000029 dmadd16 $zero,$zero
> 802b2428: 00000029 dmadd16 $zero,$zero
> 802b2458: 4d206e61 madd.d $f25,$f9,$f13,$f0
> 802b30e0: 00000029 dmadd16 $zero,$zero
> 802b3140: 00000029 dmadd16 $zero,$zero
> 802b3c68: 00000029 dmadd16 $zero,$zero
> 802b3ff8: 4f525020 madd.s $f0,$f26,$f10,$f18
> 802b4010: 4f525020 madd.s $f0,$f26,$f10,$f18
> 802b4120: 4d472030 nmadd.s $f0,$f10,$f4,$f7
> 802b453c: 4f2f4920 madd.s $f4,$f25,$f9,$f15
> 802b5d80: 00000029 dmadd16 $zero,$zero
> 802b6e38: 00000028 madd16 $zero,$zero
> 802b6e40: 00000029 dmadd16 $zero,$zero
> 802b7350: 00000028 madd16 $zero,$zero
> 802b80a8: 00000028 madd16 $zero,$zero
> 802b80b0: 00000029 dmadd16 $zero,$zero
> 802b81d8: 00000028 madd16 $zero,$zero
> 802b81e0: 00000029 dmadd16 $zero,$zero
> 802bdda4: 00000028 madd16 $zero,$zero
> 802bddd8: 00000028 madd16 $zero,$zero
> 802bde7c: 00000029 dmadd16 $zero,$zero
> 802bdeac: 00000028 madd16 $zero,$zero
> 802bdeb8: 00000028 madd16 $zero,$zero
> 802bdf14: 00000028 madd16 $zero,$zero
> 802be6d8: 00000028 madd16 $zero,$zero
> 802be764: 00000028 madd16 $zero,$zero
> 802c0578: 70000000 mad $zero,$zero
> 802c07f4: 72070000 mad $s0,$a3
> 802c1490: 00000028 madd16 $zero,$zero
> 802c957c: 00000029 dmadd16 $zero,$zero
> 802c96b0: 00000028 madd16 $zero,$zero
> 802ccdcc: 00000028 madd16 $zero,$zero
> 802cddb0: 00290028 madd16 $at,$t1
> 802cdfb0: 00290028 madd16 $at,$t1
> 802ce1b0: 00290028 madd16 $at,$t1
> 802ce6b8: 00290028 madd16 $at,$t1
> 802d4150: 4e534331 nmadd.d $f12,$f18,$f8,$f19
> 802d667c: 00000028 madd16 $zero,$zero
> 802d7614: 00290028 madd16 $at,$t1
> 802d9770: 00000028 madd16 $zero,$zero
> 802d9820: 00000029 dmadd16 $zero,$zero
