https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66239
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ramana at gcc dot gnu.org
--- Comment #2 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
(In reply to Maciej Andrzejewski from comment #1)
> It is getting even more interesting.
>
> I have disassabled 4 binaries compiled with options:
> 1) -mfloat-abi=softfp
> 2) -mfloat-abi=softfp -O
> 3) -mfloat-abi=hard
> 4) -mfloat-abi=hard -O
>
> and from what I understand if we turn ON the optimization the FPU is turned
> OFF!
> I dont see in assembler that FPU s** registers are used in those two cases
> where optimization is turned on:
Yeah it's called constant folding in the compiler. Why make the cpu do more
work at run time when the compiler can statically tell you the value for sqrt
of a floating point value. The cycles spent in compiling with -O have to give
you some value surely ... :)
I have no idea why your -O0 case fails though, offhand.
Ramana
>
> -- DISASSAMBLE OPTION 1 --
> 00010570 <main>:
> 10570: e92d4800 push {fp, lr}
> 10574: e28db004 add fp, sp, #4
> 10578: e24dd040 sub sp, sp, #64 ; 0x40
> 1057c: e3032333 movw r2, #13107 ; 0x3333
> 10580: e3432333 movt r2, #13107 ; 0x3333
> 10584: e3033333 movw r3, #13107 ; 0x3333
> 10588: e3443022 movt r3, #16418 ; 0x4022
> 1058c: e14b20fc strd r2, [fp, #-12]
> 10590: ed5b0b03 vldr d16, [fp, #-12]
> 10594: eef77be0 vcvt.f32.f64 s15, d16
> 10598: ee170a90 vmov r0, s15
> 1059c: ebffffa1 bl 10428 <sqrtf@plt>
> 105a0: ee070a90 vmov s15, r0
> 105a4: eef70ae7 vcvt.f64.f32 d16, s15
> 105a8: ed4b0b05 vstr d16, [fp, #-20] ; 0xffffffec
> 105ac: e30006cc movw r0, #1740 ; 0x6cc
> 105b0: e3400001 movt r0, #1
> 105b4: e14b21d4 ldrd r2, [fp, #-20] ; 0xffffffec
> 105b8: ebffffa0 bl 10440 <printf@plt>
> 105bc: e309399a movw r3, #39322 ; 0x999a
> 105c0: e3443111 movt r3, #16657 ; 0x4111
> 105c4: e50b3018 str r3, [fp, #-24] ; 0xffffffe8
> 105c8: e51b0018 ldr r0, [fp, #-24] ; 0xffffffe8
> 105cc: ebffff95 bl 10428 <sqrtf@plt>
> 105d0: ee070a90 vmov s15, r0
> 105d4: eef70ae7 vcvt.f64.f32 d16, s15
> 105d8: ed4b0b09 vstr d16, [fp, #-36] ; 0xffffffdc
> 105dc: e30006cc movw r0, #1740 ; 0x6cc
> 105e0: e3400001 movt r0, #1
> 105e4: e14b22d4 ldrd r2, [fp, #-36] ; 0xffffffdc
> 105e8: ebffff94 bl 10440 <printf@plt>
> 105ec: e3032333 movw r2, #13107 ; 0x3333
> 105f0: e3432333 movt r2, #13107 ; 0x3333
> 105f4: e3033333 movw r3, #13107 ; 0x3333
> 105f8: e3443022 movt r3, #16418 ; 0x4022
> 105fc: e14b22fc strd r2, [fp, #-44] ; 0xffffffd4
> 10600: e14b02dc ldrd r0, [fp, #-44] ; 0xffffffd4
> 10604: ebffff8a bl 10434 <sqrt@plt>
> 10608: e14b03f4 strd r0, [fp, #-52] ; 0xffffffcc
> 1060c: e30006cc movw r0, #1740 ; 0x6cc
> 10610: e3400001 movt r0, #1
> 10614: e14b23d4 ldrd r2, [fp, #-52] ; 0xffffffcc
> 10618: ebffff88 bl 10440 <printf@plt>
> 1061c: e309399a movw r3, #39322 ; 0x999a
> 10620: e3443111 movt r3, #16657 ; 0x4111
> 10624: e50b3038 str r3, [fp, #-56] ; 0xffffffc8
> 10628: ed5b7a0e vldr s15, [fp, #-56] ; 0xffffffc8
> 1062c: eef70ae7 vcvt.f64.f32 d16, s15
> 10630: ec510b30 vmov r0, r1, d16
> 10634: ebffff7e bl 10434 <sqrt@plt>
> 10638: e14b04f4 strd r0, [fp, #-68] ; 0xffffffbc
> 1063c: e30006cc movw r0, #1740 ; 0x6cc
> 10640: e3400001 movt r0, #1
> 10644: e14b24d4 ldrd r2, [fp, #-68] ; 0xffffffbc
> 10648: ebffff7c bl 10440 <printf@plt>
> 1064c: e3a03000 mov r3, #0
> 10650: e1a00003 mov r0, r3
> 10654: e24bd004 sub sp, fp, #4
> 10658: e8bd8800 pop {fp, pc}
> -- DISASSAMBLE OPTION 1 --
>
>
>
> -- DISASSAMBLE OPTION 2 --
> 000104f4 <main>:
> 104f4: e92d40d0 push {r4, r6, r7, lr}
> 104f8: e30045d4 movw r4, #1492 ; 0x5d4
> 104fc: e3404001 movt r4, #1
> 10500: e3a06000 mov r6, #0
> 10504: e302720a movw r7, #8714 ; 0x220a
> 10508: e3447008 movt r7, #16392 ; 0x4008
> 1050c: e1a00004 mov r0, r4
> 10510: e1a02006 mov r2, r6
> 10514: e1a03007 mov r3, r7
> 10518: ebffffa9 bl 103c4 <printf@plt>
> 1051c: e1a00004 mov r0, r4
> 10520: e1a02006 mov r2, r6
> 10524: e1a03007 mov r3, r7
> 10528: ebffffa5 bl 103c4 <printf@plt>
> 1052c: e1a00004 mov r0, r4
> 10530: e30f2d38 movw r2, #64824 ; 0xfd38
> 10534: e34f2ea1 movt r2, #65185 ; 0xfea1
> 10538: e3023209 movw r3, #8713 ; 0x2209
> 1053c: e3443008 movt r3, #16392 ; 0x4008
> 10540: ebffff9f bl 103c4 <printf@plt>
> 10544: e1a00004 mov r0, r4
> 10548: e3072c82 movw r2, #31874 ; 0x7c82
> 1054c: e340271e movt r2, #1822 ; 0x71e
> 10550: e302320a movw r3, #8714 ; 0x220a
> 10554: e3443008 movt r3, #16392 ; 0x4008
> 10558: ebffff99 bl 103c4 <printf@plt>
> 1055c: e3a00000 mov r0, #0
> 10560: e8bd80d0 pop {r4, r6, r7, pc}
> -- DISASSAMBLE OPTION 2 --
>
>
>
> -- DISASSAMBLE OPTION 3 --
> 00008578 <main>:
> 8578: e92d4800 push {fp, lr}
> 857c: e28db004 add fp, sp, #4
> 8580: e24dd040 sub sp, sp, #64 ; 0x40
> 8584: e3032333 movw r2, #13107 ; 0x3333
> 8588: e3432333 movt r2, #13107 ; 0x3333
> 858c: e3033333 movw r3, #13107 ; 0x3333
> 8590: e3443022 movt r3, #16418 ; 0x4022
> 8594: e14b20fc strd r2, [fp, #-12]
> 8598: ed5b0b03 vldr d16, [fp, #-12]
> 859c: eef77be0 vcvt.f32.f64 s15, d16
> 85a0: eeb00a67 vmov.f32 s0, s15
> 85a4: ebffffa1 bl 8430 <_init+0x44>
> 85a8: eef07a40 vmov.f32 s15, s0
> 85ac: eef70ae7 vcvt.f64.f32 d16, s15
> 85b0: ed4b0b05 vstr d16, [fp, #-20] ; 0xffffffec
> 85b4: e30806d4 movw r0, #34516 ; 0x86d4
> 85b8: e3400000 movt r0, #0
> 85bc: e14b21d4 ldrd r2, [fp, #-20] ; 0xffffffec
> 85c0: ebffffa0 bl 8448 <_init+0x5c>
> 85c4: e309399a movw r3, #39322 ; 0x999a
> 85c8: e3443111 movt r3, #16657 ; 0x4111
> 85cc: e50b3018 str r3, [fp, #-24]
> 85d0: ed1b0a06 vldr s0, [fp, #-24] ; 0xffffffe8
> 85d4: ebffff95 bl 8430 <_init+0x44>
> 85d8: eef07a40 vmov.f32 s15, s0
> 85dc: eef70ae7 vcvt.f64.f32 d16, s15
> 85e0: ed4b0b09 vstr d16, [fp, #-36] ; 0xffffffdc
> 85e4: e30806d4 movw r0, #34516 ; 0x86d4
> 85e8: e3400000 movt r0, #0
> 85ec: e14b22d4 ldrd r2, [fp, #-36] ; 0xffffffdc
> 85f0: ebffff94 bl 8448 <_init+0x5c>
> 85f4: e3032333 movw r2, #13107 ; 0x3333
> 85f8: e3432333 movt r2, #13107 ; 0x3333
> 85fc: e3033333 movw r3, #13107 ; 0x3333
> 8600: e3443022 movt r3, #16418 ; 0x4022
> 8604: e14b22fc strd r2, [fp, #-44] ; 0xffffffd4
> 8608: ed1b0b0b vldr d0, [fp, #-44] ; 0xffffffd4
> 860c: ebffff8a bl 843c <_init+0x50>
> 8610: ed0b0b0d vstr d0, [fp, #-52] ; 0xffffffcc
> 8614: e30806d4 movw r0, #34516 ; 0x86d4
> 8618: e3400000 movt r0, #0
> 861c: e14b23d4 ldrd r2, [fp, #-52] ; 0xffffffcc
> 8620: ebffff88 bl 8448 <_init+0x5c>
> 8624: e309399a movw r3, #39322 ; 0x999a
> 8628: e3443111 movt r3, #16657 ; 0x4111
> 862c: e50b3038 str r3, [fp, #-56] ; 0x38
> 8630: ed5b7a0e vldr s15, [fp, #-56] ; 0xffffffc8
> 8634: eef70ae7 vcvt.f64.f32 d16, s15
> 8638: eeb00b60 vmov.f64 d0, d16
> 863c: ebffff7e bl 843c <_init+0x50>
> 8640: ed0b0b11 vstr d0, [fp, #-68] ; 0xffffffbc
> 8644: e30806d4 movw r0, #34516 ; 0x86d4
> 8648: e3400000 movt r0, #0
> 864c: e14b24d4 ldrd r2, [fp, #-68] ; 0xffffffbc
> 8650: ebffff7c bl 8448 <_init+0x5c>
> 8654: e3a03000 mov r3, #0
> 8658: e1a00003 mov r0, r3
> 865c: e24bd004 sub sp, fp, #4
> 8660: e8bd8800 pop {fp, pc}
>
> -- DISASSAMBLE OPTION 3 --
>
>
>
> -- DISASSAMBLE OPTION 4 --
> 000084fc <main>:
> 84fc: e92d40d0 push {r4, r6, r7, lr}
> 8500: e30845dc movw r4, #34268 ; 0x85dc
> 8504: e3404000 movt r4, #0
> 8508: e3a06000 mov r6, #0
> 850c: e302720a movw r7, #8714 ; 0x220a
> 8510: e3447008 movt r7, #16392 ; 0x4008
> 8514: e1a00004 mov r0, r4
> 8518: e1a02006 mov r2, r6
> 851c: e1a03007 mov r3, r7
> 8520: ebffffa9 bl 83cc <_init+0x44>
> 8524: e1a00004 mov r0, r4
> 8528: e1a02006 mov r2, r6
> 852c: e1a03007 mov r3, r7
> 8530: ebffffa5 bl 83cc <_init+0x44>
> 8534: e1a00004 mov r0, r4
> 8538: e30f2d38 movw r2, #64824 ; 0xfd38
> 853c: e34f2ea1 movt r2, #65185 ; 0xfea1
> 8540: e3023209 movw r3, #8713 ; 0x2209
> 8544: e3443008 movt r3, #16392 ; 0x4008
> 8548: ebffff9f bl 83cc <_init+0x44>
> 854c: e1a00004 mov r0, r4
> 8550: e3072c82 movw r2, #31874 ; 0x7c82
> 8554: e340271e movt r2, #1822 ; 0x71e
> 8558: e302320a movw r3, #8714 ; 0x220a
> 855c: e3443008 movt r3, #16392 ; 0x4008
> 8560: ebffff99 bl 83cc <_init+0x44>
> 8564: e3a00000 mov r0, #0
> 8568: e8bd80d0 pop {r4, r6, r7, pc}
> -- DISASSAMBLE OPTION 4 --
>
> (In reply to Maciej Andrzejewski from comment #0)
> > Tested both on GCC 4.9.1 (compiled toolchain using crosstool-ng) and 4.9.2
> > (compiled toolchain using buildroot).
> >
> > Simple code:
> >
> > -- CODE --
> > #include <stdio.h>
> > #include <cmath>
> > #include <math.h>
> >
> >
> > int main( void )
> > {
> > double sq3 = 9.1;
> > double ret3 = sqrtf(sq3);
> > printf("%f\n", ret3);
> >
> > float sq4 = 9.1;
> > double ret4 = sqrtf(sq4);
> > printf("%f\n", ret4);
> >
> > double sq1 = 9.1;
> > double ret1 = sqrt(sq1);
> > printf("%f\n", ret1);
> >
> > float sq2 = 9.1;
> > double ret2 = sqrt(sq2);
> > printf("%f\n", ret2);
> >
> > return 0;
> > }
> > -- CODE --
> >
> > compiled with command:
> > g++ -mcpu=cortex-a8 -march=armv7-a -mtune=cortex-a8 -mfpu=neon
> > -mthumb-interwork -mfpu=neon -Wall -Wextra -mfloat-abi=softfp
> >
> > or
> >
> > g++ -mcpu=cortex-a8 -march=armv7-a -mtune=cortex-a8 -mfpu=neon
> > -mthumb-interwork -mfpu=neon -Wall -Wextra -mfloat-abi=soft
> >
> > prints output when run:
> > -- OUTPUT --
> > 0.000000
> > 0.000000
> > 89884613882771507935772421602449274280826426490922860415370742828850803088708
> > 43656890933893326861538272573183614877997670352187692139688355386197138142676
> > 33945847309741616433412271681163246268102419739642257742722331754068434663711
> > 41886318608237834273423597057507238373804952327520531541920130815989439791104
> > .000000
> > 89884613882771507935772421602449274280826426490922860415370742828850803088708
> > 43656890933893326861538272573183614877997670352187692139688355386197138142676
> > 33945847309741616433412271681163246268102419739642257742722331754068434663711
> > 41886318608237834273423597057507238373804952327520531541920130815989439791104
> > .000000
> > -- OUTPUT --
> >
> > when compiled with added ANY optimization flag (O, O1, O2, O3, Og) prints
> > proper output:
> > -- OUTPUT 2 --
> > 3.016621
> > 3.016621
> > 3.016621
> > 3.016621
> > -- OUTPUT 2 --
> >
> >
> >
> >
> > *** Additional info ***
> >
> > g++ --version:
> > arm-none-linux-gnueabi-g++ (Buildroot 2015.02) 4.9.2
> >
> > readelf -a a.out:
> > -- READELF --
> > macieja@ubuntu:~/Projects/sqrtf$ readelf -a a.out
> > ELF Header:
> > Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
> > Class: ELF32
> > Data: 2's complement, little endian
> > Version: 1 (current)
> > OS/ABI: UNIX - System V
> > ABI Version: 0
> > Type: EXEC (Executable file)
> > Machine: ARM
> > Version: 0x1
> > Entry point address: 0x103d0
> > Start of program headers: 52 (bytes into file)
> > Start of section headers: 5012 (bytes into file)
> > Flags: 0x5000202, has entry point, Version5
> > EABI, soft-float ABI
> > Size of this header: 52 (bytes)
> > Size of program headers: 32 (bytes)
> > Number of program headers: 8
> > Size of section headers: 40 (bytes)
> > Number of section headers: 29
> > Section header string table index: 26
> >
> > Section Headers:
> > [Nr] Name Type Addr Off Size ES Flg Lk
> > Inf Al
> > [ 0] NULL 00000000 000000 000000 00 0
> > 0 0
> > [ 1] .interp PROGBITS 00010134 000134 000013 00 A 0
> > 0 1
> > [ 2] .note.ABI-tag NOTE 00010148 000148 000020 00 A 0
> > 0 4
> > [ 3] .hash HASH 00010168 000168 000038 04 A 4
> > 0 4
> > [ 4] .dynsym DYNSYM 000101a0 0001a0 000090 10 A 5
> > 1 4
> > [ 5] .dynstr STRTAB 00010230 000230 0000d3 00 A 0
> > 0 1
> > [ 6] .gnu.version VERSYM 00010304 000304 000012 02 A 4
> > 0 2
> > [ 7] .gnu.version_r VERNEED 00010318 000318 000040 00 A 5
> > 2 4
> > [ 8] .rel.dyn REL 00010358 000358 000008 08 A 4
> > 0 4
> > [ 9] .rel.plt REL 00010360 000360 000020 08 AI 4
> > 11 4
> > [10] .init PROGBITS 00010380 000380 00000c 00 AX 0
> > 0 4
> > [11] .plt PROGBITS 0001038c 00038c 000044 04 AX 0
> > 0 4
> > [12] .text PROGBITS 000103d0 0003d0 0001f8 00 AX 0
> > 0 4
> > [13] .fini PROGBITS 000105c8 0005c8 000008 00 AX 0
> > 0 4
> > [14] .rodata PROGBITS 000105d0 0005d0 000008 00 A 0
> > 0 4
> > [15] .ARM.exidx ARM_EXIDX 000105d8 0005d8 000018 00 AL 12
> > 0 4
> > [16] .eh_frame PROGBITS 000105f0 0005f0 000004 00 A 0
> > 0 4
> > [17] .init_array INIT_ARRAY 000205f4 0005f4 000004 00 WA 0
> > 0 4
> > [18] .fini_array FINI_ARRAY 000205f8 0005f8 000004 00 WA 0
> > 0 4
> > [19] .jcr PROGBITS 000205fc 0005fc 000004 00 WA 0
> > 0 4
> > [20] .dynamic DYNAMIC 00020600 000600 000100 08 WA 5
> > 0 4
> > [21] .got PROGBITS 00020700 000700 000020 04 WA 0
> > 0 4
> > [22] .data PROGBITS 00020720 000720 000008 00 WA 0
> > 0 4
> > [23] .bss NOBITS 00020728 000728 000004 00 WA 0
> > 0 1
> > [24] .comment PROGBITS 00000000 000728 00001f 01 MS 0
> > 0 1
> > [25] .ARM.attributes ARM_ATTRIBUTES 00000000 000747 000037 00 0
> > 0 1
> > [26] .shstrtab STRTAB 00000000 00077e 0000f3 00 0
> > 0 1
> > [27] .symtab SYMTAB 00000000 000874 000700 10 28
> > 86 4
> > [28] .strtab STRTAB 00000000 000f74 00041e 00 0
> > 0 1
> > Key to Flags:
> > W (write), A (alloc), X (execute), M (merge), S (strings)
> > I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
> > O (extra OS processing required) o (OS specific), p (processor specific)
> >
> > There are no section groups in this file.
> >
> > Program Headers:
> > Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
> > EXIDX 0x0005d8 0x000105d8 0x000105d8 0x00018 0x00018 R 0x4
> > PHDR 0x000034 0x00010034 0x00010034 0x00100 0x00100 R E 0x4
> > INTERP 0x000134 0x00010134 0x00010134 0x00013 0x00013 R 0x1
> > [Requesting program interpreter: /lib/ld-linux.so.3]
> > LOAD 0x000000 0x00010000 0x00010000 0x005f4 0x005f4 R E 0x10000
> > LOAD 0x0005f4 0x000205f4 0x000205f4 0x00134 0x00138 RW 0x10000
> > DYNAMIC 0x000600 0x00020600 0x00020600 0x00100 0x00100 RW 0x4
> > NOTE 0x000148 0x00010148 0x00010148 0x00020 0x00020 R 0x4
> > GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0x10
> >
> > Section to Segment mapping:
> > Segment Sections...
> > 00 .ARM.exidx
> > 01
> > 02 .interp
> > 03 .interp .note.ABI-tag .hash .dynsym .dynstr .gnu.version
> > .gnu.version_r .rel.dyn .rel.plt .init .plt .text .fini .rodata .ARM.exidx
> > .eh_frame
> > 04 .init_array .fini_array .jcr .dynamic .got .data .bss
> > 05 .dynamic
> > 06 .note.ABI-tag
> > 07
> >
> > Dynamic section at offset 0x600 contains 27 entries:
> > Tag Type Name/Value
> > 0x00000001 (NEEDED) Shared library: [libstdc++.so.6]
> > 0x00000001 (NEEDED) Shared library: [libm.so.6]
> > 0x00000001 (NEEDED) Shared library: [libgcc_s.so.1]
> > 0x00000001 (NEEDED) Shared library: [libc.so.6]
> > 0x0000000c (INIT) 0x10380
> > 0x0000000d (FINI) 0x105c8
> > 0x00000019 (INIT_ARRAY) 0x205f4
> > 0x0000001b (INIT_ARRAYSZ) 4 (bytes)
> > 0x0000001a (FINI_ARRAY) 0x205f8
> > 0x0000001c (FINI_ARRAYSZ) 4 (bytes)
> > 0x00000004 (HASH) 0x10168
> > 0x00000005 (STRTAB) 0x10230
> > 0x00000006 (SYMTAB) 0x101a0
> > 0x0000000a (STRSZ) 211 (bytes)
> > 0x0000000b (SYMENT) 16 (bytes)
> > 0x00000015 (DEBUG) 0x0
> > 0x00000003 (PLTGOT) 0x20700
> > 0x00000002 (PLTRELSZ) 32 (bytes)
> > 0x00000014 (PLTREL) REL
> > 0x00000017 (JMPREL) 0x10360
> > 0x00000011 (REL) 0x10358
> > 0x00000012 (RELSZ) 8 (bytes)
> > 0x00000013 (RELENT) 8 (bytes)
> > 0x6ffffffe (VERNEED) 0x10318
> > 0x6fffffff (VERNEEDNUM) 2
> > 0x6ffffff0 (VERSYM) 0x10304
> > 0x00000000 (NULL) 0x0
> >
> > Relocation section '.rel.dyn' at offset 0x358 contains 1 entries:
> > Offset Info Type Sym.Value Sym. Name
> > 0002071c 00000415 R_ARM_GLOB_DAT 00000000 __gmon_start__
> >
> > Relocation section '.rel.plt' at offset 0x360 contains 4 entries:
> > Offset Info Type Sym.Value Sym. Name
> > 0002070c 00000116 R_ARM_JUMP_SLOT 00000000 abort
> > 00020710 00000216 R_ARM_JUMP_SLOT 00000000 __libc_start_main
> > 00020714 00000416 R_ARM_JUMP_SLOT 00000000 __gmon_start__
> > 00020718 00000816 R_ARM_JUMP_SLOT 00000000 printf
> >
> > Unwind table index '.ARM.exidx' at offset 0x5d8 contains 3 entries:
> >
> > 0x103d0 <_start>: 0x1 [cantunwind]
> >
> > 0x104f4 <main>: 0x80840db0
> > Compact model index: 0
> > 0x84 0x0d pop {r4, r6, r7, r14}
> > 0xb0 finish
> >
> > 0x10564 <__libc_csu_init>: 0x1 [cantunwind]
> >
> >
> > Symbol table '.dynsym' contains 9 entries:
> > Num: Value Size Type Bind Vis Ndx Name
> > 0: 00000000 0 NOTYPE LOCAL DEFAULT UND
> > 1: 00000000 0 FUNC GLOBAL DEFAULT UND abort@GLIBC_2.4 (2)
> > 2: 00000000 0 FUNC GLOBAL DEFAULT UND
> > __libc_start_main@GLIBC_2.4 (2)
> > 3: 00000000 0 FUNC GLOBAL DEFAULT UND
> > __aeabi_unwind_cpp_pr0@GCC_3.5 (3)
> > 4: 00000000 0 NOTYPE WEAK DEFAULT UND __gmon_start__
> > 5: 00000000 0 NOTYPE WEAK DEFAULT UND _Jv_RegisterClasses
> > 6: 00000000 0 NOTYPE WEAK DEFAULT UND _ITM_deregisterTMCloneTab
> > 7: 00000000 0 NOTYPE WEAK DEFAULT UND _ITM_registerTMCloneTable
> > 8: 00000000 0 FUNC GLOBAL DEFAULT UND printf@GLIBC_2.4 (2)
> >
> > Symbol table '.symtab' contains 112 entries:
> > Num: Value Size Type Bind Vis Ndx Name
> > 0: 00000000 0 NOTYPE LOCAL DEFAULT UND
> > 1: 00010134 0 SECTION LOCAL DEFAULT 1
> > 2: 00010148 0 SECTION LOCAL DEFAULT 2
> > 3: 00010168 0 SECTION LOCAL DEFAULT 3
> > 4: 000101a0 0 SECTION LOCAL DEFAULT 4
> > 5: 00010230 0 SECTION LOCAL DEFAULT 5
> > 6: 00010304 0 SECTION LOCAL DEFAULT 6
> > 7: 00010318 0 SECTION LOCAL DEFAULT 7
> > 8: 00010358 0 SECTION LOCAL DEFAULT 8
> > 9: 00010360 0 SECTION LOCAL DEFAULT 9
> > 10: 00010380 0 SECTION LOCAL DEFAULT 10
> > 11: 0001038c 0 SECTION LOCAL DEFAULT 11
> > 12: 000103d0 0 SECTION LOCAL DEFAULT 12
> > 13: 000105c8 0 SECTION LOCAL DEFAULT 13
> > 14: 000105d0 0 SECTION LOCAL DEFAULT 14
> > 15: 000105d8 0 SECTION LOCAL DEFAULT 15
> > 16: 000105f0 0 SECTION LOCAL DEFAULT 16
> > 17: 000205f4 0 SECTION LOCAL DEFAULT 17
> > 18: 000205f8 0 SECTION LOCAL DEFAULT 18
> > 19: 000205fc 0 SECTION LOCAL DEFAULT 19
> > 20: 00020600 0 SECTION LOCAL DEFAULT 20
> > 21: 00020700 0 SECTION LOCAL DEFAULT 21
> > 22: 00020720 0 SECTION LOCAL DEFAULT 22
> > 23: 00020728 0 SECTION LOCAL DEFAULT 23
> > 24: 00000000 0 SECTION LOCAL DEFAULT 24
> > 25: 00000000 0 SECTION LOCAL DEFAULT 25
> > 26: 00000000 0 FILE LOCAL DEFAULT ABS /home/macieja/Documents/b
> > 27: 00010148 0 NOTYPE LOCAL DEFAULT 2 $d
> > 28: 00000000 0 FILE LOCAL DEFAULT ABS /home/macieja/Documents/b
> > 29: 000103d0 0 NOTYPE LOCAL DEFAULT 12 $a
> > 30: 000105d8 0 NOTYPE LOCAL DEFAULT 15 $d
> > 31: 00010400 0 NOTYPE LOCAL DEFAULT 12 $d
> > 32: 00000000 0 FILE LOCAL DEFAULT ABS init.c
> > 33: 000105d0 0 NOTYPE LOCAL DEFAULT 14 $d
> > 34: 00020720 0 NOTYPE LOCAL DEFAULT 22 $d
> > 35: 00000000 0 FILE LOCAL DEFAULT ABS /usr/local/buildroot_cort
> > 36: 0001040c 0 NOTYPE LOCAL DEFAULT 12 $a
> > 37: 0001040c 0 FUNC LOCAL DEFAULT 12 call_weak_fn
> > 38: 00010428 0 NOTYPE LOCAL DEFAULT 12 $d
> > 39: 00010380 0 NOTYPE LOCAL DEFAULT 10 $a
> > 40: 000105c8 0 NOTYPE LOCAL DEFAULT 13 $a
> > 41: 00000000 0 FILE LOCAL DEFAULT ABS /usr/local/buildroot_cort
> > 42: 00010388 0 NOTYPE LOCAL DEFAULT 10 $a
> > 43: 000105cc 0 NOTYPE LOCAL DEFAULT 13 $a
> > 44: 00000000 0 FILE LOCAL DEFAULT ABS crtstuff.c
> > 45: 000205fc 0 OBJECT LOCAL DEFAULT 19 __JCR_LIST__
> > 46: 00010430 0 NOTYPE LOCAL DEFAULT 12 $a
> > 47: 00010430 0 FUNC LOCAL DEFAULT 12 deregister_tm_clones
> > 48: 00010454 0 NOTYPE LOCAL DEFAULT 12 $d
> > 49: 00010460 0 NOTYPE LOCAL DEFAULT 12 $a
> > 50: 00010460 0 FUNC LOCAL DEFAULT 12 register_tm_clones
> > 51: 0001048c 0 NOTYPE LOCAL DEFAULT 12 $d
> > 52: 00020724 0 NOTYPE LOCAL DEFAULT 22 $d
> > 53: 00010498 0 NOTYPE LOCAL DEFAULT 12 $a
> > 54: 00010498 0 FUNC LOCAL DEFAULT 12 __do_global_dtors_aux
> > 55: 000104bc 0 NOTYPE LOCAL DEFAULT 12 $d
> > 56: 00020728 1 OBJECT LOCAL DEFAULT 23 completed.8966
> > 57: 000205f8 0 NOTYPE LOCAL DEFAULT 18 $d
> > 58: 000205f8 0 OBJECT LOCAL DEFAULT 18 __do_global_dtors_aux_fin
> > 59: 000104c0 0 NOTYPE LOCAL DEFAULT 12 $a
> > 60: 000104c0 0 FUNC LOCAL DEFAULT 12 frame_dummy
> > 61: 000104ec 0 NOTYPE LOCAL DEFAULT 12 $d
> > 62: 000205f4 0 NOTYPE LOCAL DEFAULT 17 $d
> > 63: 000205f4 0 OBJECT LOCAL DEFAULT 17 __frame_dummy_init_array_
> > 64: 00020728 0 NOTYPE LOCAL DEFAULT 23 $d
> > 65: 00000000 0 FILE LOCAL DEFAULT ABS main.c
> > 66: 000104f4 0 NOTYPE LOCAL DEFAULT 12 $a
> > 67: 000105e0 0 NOTYPE LOCAL DEFAULT 15 $d
> > 68: 000105d4 0 NOTYPE LOCAL DEFAULT 14 $d
> > 69: 00000000 0 FILE LOCAL DEFAULT ABS elf-init.c
> > 70: 00010564 0 NOTYPE LOCAL DEFAULT 12 $a
> > 71: 000105bc 0 NOTYPE LOCAL DEFAULT 12 $d
> > 72: 000105c4 0 NOTYPE LOCAL DEFAULT 12 $a
> > 73: 00000000 0 FILE LOCAL DEFAULT ABS crtstuff.c
> > 74: 000105f0 0 NOTYPE LOCAL DEFAULT 16 $d
> > 75: 000105f0 0 OBJECT LOCAL DEFAULT 16 __FRAME_END__
> > 76: 000205fc 0 NOTYPE LOCAL DEFAULT 19 $d
> > 77: 000205fc 0 OBJECT LOCAL DEFAULT 19 __JCR_END__
> > 78: 00000000 0 FILE LOCAL DEFAULT ABS
> > 79: 00020700 0 OBJECT LOCAL DEFAULT 21 _GLOBAL_OFFSET_TABLE_
> > 80: 000205f8 0 NOTYPE LOCAL DEFAULT 17 __init_array_end
> > 81: 000205f4 0 NOTYPE LOCAL DEFAULT 17 __init_array_start
> > 82: 00020600 0 OBJECT LOCAL DEFAULT 20 _DYNAMIC
> > 83: 0001038c 0 NOTYPE LOCAL DEFAULT 11 $a
> > 84: 0001039c 0 NOTYPE LOCAL DEFAULT 11 $d
> > 85: 000103a0 0 NOTYPE LOCAL DEFAULT 11 $a
> > 86: 00020720 0 NOTYPE WEAK DEFAULT 22 data_start
> > 87: 00000000 0 FUNC GLOBAL DEFAULT UND abort@@GLIBC_2.4
> > 88: 000105c4 4 FUNC GLOBAL DEFAULT 12 __libc_csu_fini
> > 89: 000103d0 0 FUNC GLOBAL DEFAULT 12 _start
> > 90: 00000000 0 FUNC GLOBAL DEFAULT UND __libc_start_main@@GLIBC_
> > 91: 00000000 0 FUNC GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr0@@G
> > 92: 00000000 0 NOTYPE WEAK DEFAULT UND __gmon_start__
> > 93: 00000000 0 NOTYPE WEAK DEFAULT UND _Jv_RegisterClasses
> > 94: 000105c8 0 FUNC GLOBAL DEFAULT 13 _fini
> > 95: 00000000 0 NOTYPE WEAK DEFAULT UND _ITM_deregisterTMCloneTab
> > 96: 000105d0 4 OBJECT GLOBAL DEFAULT 14 _IO_stdin_used
> > 97: 00000000 0 NOTYPE WEAK DEFAULT UND _ITM_registerTMCloneTable
> > 98: 00020720 0 NOTYPE GLOBAL DEFAULT 22 __data_start
> > 99: 00020728 0 NOTYPE GLOBAL DEFAULT 23 __bss_start__
> > 100: 00020728 0 OBJECT GLOBAL HIDDEN 22 __TMC_END__
> > 101: 00020724 0 OBJECT GLOBAL HIDDEN 22 __dso_handle
> > 102: 0002072c 0 NOTYPE GLOBAL DEFAULT 23 __end__
> > 103: 00010564 96 FUNC GLOBAL DEFAULT 12 __libc_csu_init
> > 104: 0002072c 0 NOTYPE GLOBAL DEFAULT 23 __bss_end__
> > 105: 00000000 0 FUNC GLOBAL DEFAULT UND printf@@GLIBC_2.4
> > 106: 00020728 0 NOTYPE GLOBAL DEFAULT 23 __bss_start
> > 107: 0002072c 0 NOTYPE GLOBAL DEFAULT 23 _bss_end__
> > 108: 0002072c 0 NOTYPE GLOBAL DEFAULT 23 _end
> > 109: 00020728 0 NOTYPE GLOBAL DEFAULT 22 _edata
> > 110: 000104f4 112 FUNC GLOBAL DEFAULT 12 main
> > 111: 00010380 0 FUNC GLOBAL DEFAULT 10 _init
> >
> > Histogram for bucket list length (total of 3 buckets):
> > Length Number % of total Coverage
> > 0 0 ( 0.0%)
> > 1 0 ( 0.0%) 0.0%
> > 2 2 ( 66.7%) 50.0%
> > 3 0 ( 0.0%) 50.0%
> > 4 1 ( 33.3%) 100.0%
> >
> > Version symbols section '.gnu.version' contains 9 entries:
> > Addr: 0000000000010304 Offset: 0x000304 Link: 4 (.dynsym)
> > 000: 0 (*local*) 2 (GLIBC_2.4) 2 (GLIBC_2.4) 3 (GCC_3.5)
> >
> > 004: 0 (*local*) 0 (*local*) 0 (*local*) 0 (*local*)
> >
> > 008: 2 (GLIBC_2.4)
> >
> > Version needs section '.gnu.version_r' contains 2 entries:
> > Addr: 0x0000000000010318 Offset: 0x000318 Link: 5 (.dynstr)
> > 000000: Version: 1 File: libgcc_s.so.1 Cnt: 1
> > 0x0010: Name: GCC_3.5 Flags: none Version: 3
> > 0x0020: Version: 1 File: libc.so.6 Cnt: 1
> > 0x0030: Name: GLIBC_2.4 Flags: none Version: 2
> >
> > Displaying notes found at file offset 0x00000148 with length 0x00000020:
> > Owner Data size Description
> > GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag)
> > OS: Linux, ABI: 2.6.32
> > Attribute Section: aeabi
> > File Attributes
> > Tag_CPU_name: "Cortex-A8"
> > Tag_CPU_arch: v7
> > Tag_CPU_arch_profile: Application
> > Tag_ARM_ISA_use: Yes
> > Tag_THUMB_ISA_use: Thumb-2
> > Tag_ABI_PCS_wchar_t: 4
> > Tag_ABI_FP_rounding: Needed
> > Tag_ABI_FP_denormal: Needed
> > Tag_ABI_FP_exceptions: Needed
> > Tag_ABI_FP_number_model: IEEE 754
> > Tag_ABI_align_needed: 8-byte
> > Tag_ABI_align_preserved: 8-byte, except leaf SP
> > Tag_ABI_enum_size: int
> > Tag_CPU_unaligned_access: v6
> > Tag_Virtualization_use: TrustZone
> > -- READELF --
