implicit conversion from 'float' to 'double' [-Wdouble-promotion]

[fixus971]

Hardware WiFimanager Branch/Release: Master Esp32

Problem description: warning: implicit conversion from 'float' to 'double' to match other operand of binary expression [-Wdouble-promotion]

Line 2269: p.replace(FPSTR(T_2),(String)((temperatureRead()+32)*1.8));

*1.8 Issue at end of line

Solution replace with *1.8f

[fixus971]

Hi. Is warning of compiler in c17 version.

even if normally this warning is not signaled.. it is still a problem for 32 bit CPUs.

I corrected many similar arithmetic calculations because I saw the explanation and I tested it: the 32bit CPUs of the Arduino world suffer a lot from double counts that go beyond 32bit. Needed .. but just put an "f" and everything falls into place

Il mer 17 mag 2023, 03:11 Shawn A @.***> ha scritto:

I don't get these warnings

build_flags: -Wall -Wdouble-promotion

what flags?

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[fixus971]

Some info about double calc on arduino hardware: https://forum.arduino.cc/t/8bit-vs-32bit-floating-point-calculations/543123/11

I see that int and a float is 4 bytes and a double is 8 bytes. after that i read and tested that double require more software time. (Double)

I used platformio with:

[env:Esp32] framework = arduino platform = espressif32 board = az-delivery-devkit-v4 upload_speed = 921600

monitor_speed = 115200 monitor_filters = direct ;EscChar to console wo filtering = colors

build_unflags = -std=c++11 -std=gnu++11 -Os

build_flags = -DCORE_DEBUG_LEVEL=ARDUHAL_LOG_LEVEL_DEBUG ;=4 -O3 -std=c++17 -std=gnu++17 -Wall ;en warnings questionable constructions that are easy to avoid -Wextra ;en extra warning flags that are not enabled by -Wall. -Wdouble-promotion ; warn double soft64b:.9(def=double)->.9f -Wimplicit-fallthrough ; warn if switch case without break -Wreturn-type -Werror=return-type ; no return(x) -> CPU Exception hard to found

[tablatronix]

Thanks for that!