Stable version libm.a compilation error

Compiling project using libm.a throws:
packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o):(.literal+0xf8): undefined reference to `__ieee754_sqrt'

packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o): In function __ieee754_pow': d:\ivan\projects\arduinoesp\toolchain\dl\esp-newlib\build\xtensa-lx106-elf\newlib\libm\math/../../../../../newlib/libm/math/e_pow.c:164: undefined reference to__ieee754_sqrt'
collect2.exe: error: ld returned 1 exit status

Some hints how to deal with this? Thanks

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[krulkip]

I get same problem.

Arduino: 1.6.5 (Windows 7), Board: "Generic ESP8266 Module, Serial, 80 MHz, 40MHz, DIO, 115200, 512K (64K SPIFFS)"

j:/arduino-1.6.5-r2/portable/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o):(.literal+0xec): undefined reference to __ieee754_sqrt' j:/arduino-1.6.5-r2/portable/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o): In function__ieee754_pow':
d:\ivan\projects\arduinoesp\toolchain\dl\esp-newlib\build\xtensa-lx106-elf\newlib\libm\math/../../../../../newlib/libm/math/e_pow.c:164: undefined reference to `__ieee754_sqrt'
collect2.exe: error: ld returned 1 exit status

[forkineye]

Experiencing this as well / windows 8.1 and Arduino 1.6.5-r2
Arduino: 1.6.5 (Windows 8.1), Board: "NodeMCU 1.0 (ESP-12E Module), 80 MHz, 115200"

c:/users/xxxx/appdata/roaming/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o):(.literal+0x104): undefined reference to __ieee754_sqrt' c:/users/xxxx/appdata/roaming/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o): In function __ieee754_pow':
d:\ivan\projects\arduinoesp\toolchain\dl\esp-newlib\build\xtensa-lx106-elf\newlib\libm\math/../../../../../newlib/libm/math/e_pow.c:164: undefined reference to __ieee754_sqrt'`
collect2.exe: error: ld returned 1 exit status

[igrr]

I think the workaround is to delete the downloaded package (it's somewhere
in the user folder on Windows) as well as downloaded toolchain archive.
Arduino doesn't download the file again even though the size and checksum
had changed.

I will bump toolchain version for the next release.

On Tue, Jul 28, 2015, 20:23 Shelby Merrick notifications@github.com wrote:

Experiencing this as well / windows 8.1 and Arduino 1.6.5-r2
Arduino: 1.6.5 (Windows 8.1), Board: "NodeMCU 1.0 (ESP-12E Module), 80
MHz, 115200"

c:/users/xxxx/appdata/roaming/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o):(.literal+0x104):
undefined reference to __ieee754_sqrt' c:/users/xxxx/appdata/roaming/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-e_pow.o): In function__ieee754_pow':
d:\ivan\projects\arduinoesp\toolchain\dl\esp-newlib\build\xtensa-lx106-elf\newlib\libm\math/../../../../../newlib/libm/math/e_pow.c:164:
undefined reference to `__ieee754_sqrt'

collect2.exe: error: ld returned 1 exit status

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Reply to this email directly or view it on GitHub
#612 (comment).

[forkineye]

@igrr I just tried that out, removing the ESP8266 board from the Arduino IDE and then removing all ESP and xtensa references located in the users\<user>\appdata\arduino15 packaging and staging directories. Same issue when trying to call pow().

Example from a gamma table generation loop: Serial.print((int)(255 * pow((i / 255), gamma)));

[forkineye]

I'm able to recreate this issue, but only with floats inside of loops. Code to re-create is here - https://gist.github.com/forkineye/d05909c5c0184c7300ae. The toolchain is 1.20.0-26-gb404fb9. Toolchain archive is win32-xtensa-lx106-elf-gb404fb9.tar.gz with a MD5 hash of 7e6cf4fb104022ddee0b9ef716232439

void setup() {
    Serial.begin(115200);
    Serial.println("");

    float x = 2.0; 
    float y = 2.2;

    int i;
    for(i = 0; i < 10; i++) {
        Serial.println(pow(i, x));
        Serial.println(pow(i, y));    // Fails to compile
    }
    Serial.println(pow(i, y));        // Compiles fine, 10 ^ 2.2
}

void loop() {

}

[krulkip]

This seems to refer to a fix for this issue, but not sure how to try
jcmvbkbc/crosstool-NG@b404fb9

[igrr]

Windows toolchain is not built using crosstool-NG, so probably not exactly
relevant.

On Sun, Aug 9, 2015, 00:41 krulkip notifications@github.com wrote:

This seems to refer to a fix for this issue, but not sure how to try
jcmvbkbc/crosstool-NG@b404fb9
jcmvbkbc/crosstool-NG@b404fb9

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Reply to this email directly or view it on GitHub
#612 (comment).

[krulkip]

I installed this libm.a file replacing the xisting one in 1.20.0-26-gb404fb9/xtensa-lx106-elf/lib/ and the error was solved.
https://files.gitter.im/esp8266/Arduino/Abqa/libm.a.tbz

[Testato]

same problem here, i use the Stable version on Win7-64

Is it solved on Staging Version ?

[locchi93]

same problem on windows using the current Stable version and Arduino ide 1.6.5

[Testato]

@krulkip
Thanks, whit your lib there is no problem

[erhome00]

Testato or igrr,

can you please tell me how exactly I use that corrected LIB? I have the same problem and am not able to solve it...