"impossible constraint in 'asm'" error when adding single-precision hard-float 'sqrt'

[Jim (Jim Sughrue)]

Hi Remember,

I’m not sure about the impossible constraint in ‘asm’” error message but would this thread below help you?

Float compiler sqrt

I’m not seeing that. I tried compiling… #include <math.h> float af(float n){return sqrtf(n);} double ad(double n){return sqrt(n);} and got quite a bit of code, but it does include sqrt instructions bruce@nuc:~/riscv/tests$ riscv64-unknown-elf-gcc -O -c sqrt.c bruce@nuc:~/riscv/tests$ riscv64-unknown-elf-objdump -d sqrt.o sqrt.o: file format elf64-littleriscv Disassembly of section .text: 0000000000000000 <af>: 0: 1101 addi sp,sp,-32 2: ec06 …