micropython/lib/libm_dbl/thumb_vfp_sqrt.c
Jim Mussared 580a2656d1 stm32: Use hardware double sqrt on F7/H7 MCUs.
Identical to cd527bb324 but for doubles.
This gives a -2.754% improvement on bm_float.py, and -35% improvement on
calling sqrt in a loop.
2019-10-10 17:39:32 +11:00

11 lines
252 B
C

// an implementation of sqrt for Thumb using hardware double-precision VFP instructions
double sqrt(double x) {
double ret;
asm volatile (
"vsqrt.f64 %P0, %P1\n"
: "=w" (ret)
: "w" (x));
return ret;
}