http://sources.redhat.com/ml/newlib/2002/msg00230.html Stephen L Moshier wrote: > > pow(x,y) returns 0 when x is very close to -1.0 and y is very large. > The following test program prints > > pow(1.0000000000000002e+00 4.5035996273704970e+15) = 2.7182818284590455e+00 > pow(-1.0000000000000002e+00 4.5035996273704970e+15) =0.0000000000000000e+00 > pow(9.9999999999999978e-01 4.5035996273704970e+15) = 3.6787944117144222e-01 > pow(-9.9999999999999978e-01 4.5035996273704970e+15) = 0.0000000000000000e+00 > > which is incorrect for the negative arguments raised to an odd integer > power. > > ----- > double pow (double, double); > > int > main () > { > double x, y, z; > > x = 1.0 + pow (2.0, -52.0); > y = 1.0 + pow (2.0, 52.0); > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = -x; > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = 1.0 - pow (2.0, -52.0); > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > x = -x; > z = pow (x, y); > printf ("pow(%.16e %.16e) = %.16e\n", x, y, z); > } > ----- > > Here is a patch for newlib/libm/math/epow.c: Patch checked in and duplicated for ef_pow.c. Thanks. -- Jeff J.

# Makefile to build the SDL library

INCLUDE = -I./include
CFLAGS  = -g -O2 $(INCLUDE)
AR	= ar
RANLIB	= ranlib

CONFIG_H = include/SDL_config.h
TARGET  = libSDL.a
SOURCES = \
	src/*.c \
	src/audio/*.c \
	src/cdrom/*.c \
	src/cpuinfo/*.c \
	src/events/*.c \
	src/file/*.c \
	src/joystick/*.c \
	src/haptic/*.c \
	src/stdlib/*.c \
	src/thread/*.c \
	src/timer/*.c \
	src/video/*.c \
	src/audio/dummy/*.c \
	src/video/dummy/*.c \
	src/joystick/dummy/*.c \
	src/haptic/dummy/*.c \
	src/cdrom/dummy/*.c \
	src/thread/generic/*.c \
	src/timer/dummy/*.c \
	src/loadso/dummy/*.c \

OBJECTS = $(shell echo $(SOURCES) | sed -e 's,\.c,\.o,g')

all: $(TARGET)

$(TARGET): $(CONFIG_H) $(OBJECTS)
	$(AR) crv $@ $^
	$(RANLIB) $@

$(CONFIG_H):
	cp $(CONFIG_H).default $(CONFIG_H)

clean:
	rm -f $(TARGET) $(OBJECTS)