diff --git a/lib/libm_dbl/thumb_vfp_sqrt.c b/lib/libm_dbl/thumb_vfp_sqrt.c new file mode 100644 index 0000000000..dd37a07b05 --- /dev/null +++ b/lib/libm_dbl/thumb_vfp_sqrt.c @@ -0,0 +1,10 @@ +// 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; +} diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile index 1a4e3c6902..28b90199ae 100644 --- a/ports/stm32/Makefile +++ b/ports/stm32/Makefile @@ -173,12 +173,16 @@ SRC_LIBM = $(addprefix lib/libm_dbl/,\ scalbn.c \ sin.c \ sinh.c \ - sqrt.c \ tan.c \ tanh.c \ tgamma.c \ trunc.c \ ) +ifeq ($(MCU_SERIES),$(filter $(MCU_SERIES),f7 h7)) +SRC_LIBM += lib/libm_dbl/thumb_vfp_sqrt.c +else +SRC_LIBM += lib/libm_dbl/sqrt.c +endif else SRC_LIBM = $(addprefix lib/libm/,\ math.c \