It appears that with recent versions of GCC the explicit "-mhard-float" command line option takes precedence over the ``asm(".gnu_attribute 4, 2");'' in the source file, so this no longer helps to avoid the warnings we get when linking code that uses FP instructions with other code that was built using soft-float.
We can remove the ".gnu_attribute" (which appears to carry no other information, at least so far) from the object files, but we also have to make sure we don't pull in the __gcc_qsub() and __gcc_qmul() functions from the standard libgcc, as these would again "infect" our linking. We copy this code from: gcc-4.2.2/gcc/config/rs6000/darwin-ldouble.c This old version was chosen because it was still available under a compatible license (GCC v2+). The file was stripped down to the needed parts, and reformatted so it passes checkpatch with only one warning (do not add new typedefs).
Signed-off-by: Wolfgang Denk wd@denx.de Cc: Kumar Gala galak@kernel.crashing.org Cc: Stefan Roese sr@denx.de Cc: Andy Fleming afleming@gmail.com Cc: Kim Phillips kim.phillips@freescale.com --- This patch silences build warnings for the following boards: aev BC3450 charon, cm5200 fo300 korat korat_perm lwmon5 MiniFAP PMC440 sacsng sequoia sequoia_nand sequoia_ramboot TB5200 TB5200_B TQM5200 TQM5200_B TQM5200_B_HIGHBOOT TQM5200S TQM5200S_HIGHBOOT TQM5200_STK100
post/lib_powerpc/fpu/Makefile | 17 ++++- post/lib_powerpc/fpu/darwin-ldouble.c | 141 +++++++++++++++++++++++++++++++++ 2 files changed, 156 insertions(+), 2 deletions(-) create mode 100644 post/lib_powerpc/fpu/darwin-ldouble.c
diff --git a/post/lib_powerpc/fpu/Makefile b/post/lib_powerpc/fpu/Makefile index b97ad6f..5d0e52d 100644 --- a/post/lib_powerpc/fpu/Makefile +++ b/post/lib_powerpc/fpu/Makefile @@ -24,10 +24,23 @@ include $(TOPDIR)/config.mk
LIB = libpost$(ARCH)fpu.o
-COBJS-$(CONFIG_HAS_POST) += fpu.o 20001122-1.o 20010114-2.o 20010226-1.o 980619-1.o -COBJS-$(CONFIG_HAS_POST) += acc1.o compare-fp-1.o mul-subnormal-single-1.o +COBJS-$(CONFIG_HAS_POST) += 20001122-1.o +COBJS-$(CONFIG_HAS_POST) += 20010114-2.o +COBJS-$(CONFIG_HAS_POST) += 20010226-1.o +COBJS-$(CONFIG_HAS_POST) += 980619-1.o +COBJS-$(CONFIG_HAS_POST) += acc1.o +COBJS-$(CONFIG_HAS_POST) += compare-fp-1.o +COBJS-$(CONFIG_HAS_POST) += fpu.o +COBJS-$(CONFIG_HAS_POST) += mul-subnormal-single-1.o + +COBJS-$(CONFIG_HAS_POST) += darwin-ldouble.o
include $(TOPDIR)/post/rules.mk
CFLAGS := $(shell echo $(CFLAGS) | sed s/-msoft-float//) CFLAGS += -mhard-float -fkeep-inline-functions + +$(obj)%.o: %.c + $(CC) $(ALL_CFLAGS) -o $@.fp $< -c + $(OBJCOPY) -R .gnu.attributes $@.fp $@ + rm -f $@.fp diff --git a/post/lib_powerpc/fpu/darwin-ldouble.c b/post/lib_powerpc/fpu/darwin-ldouble.c new file mode 100644 index 0000000..41ae202 --- /dev/null +++ b/post/lib_powerpc/fpu/darwin-ldouble.c @@ -0,0 +1,141 @@ +/* + * Borrowed from GCC 4.2.2 (which still was GPL v2+) + */ +/* 128-bit long double support routines for Darwin. + Copyright (C) 1993, 2003, 2004, 2005, 2006, 2007 + Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +In addition to the permissions in the GNU General Public License, the +Free Software Foundation gives you unlimited permission to link the +compiled version of this file into combinations with other programs, +and to distribute those combinations without any restriction coming +from the use of this file. (The General Public License restrictions +do apply in other respects; for example, they cover modification of +the file, and distribution when not linked into a combine +executable.) + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + +/* + * Implementations of floating-point long double basic arithmetic + * functions called by the IBM C compiler when generating code for + * PowerPC platforms. In particular, the following functions are + * implemented: __gcc_qadd, __gcc_qsub, __gcc_qmul, and __gcc_qdiv. + * Double-double algorithms are based on the paper "Doubled-Precision + * IEEE Standard 754 Floating-Point Arithmetic" by W. Kahan, February 26, + * 1987. An alternative published reference is "Software for + * Doubled-Precision Floating-Point Computations", by Seppo Linnainmaa, + * ACM TOMS vol 7 no 3, September 1981, pages 272-283. + */ + +/* + * Each long double is made up of two IEEE doubles. The value of the + * long double is the sum of the values of the two parts. The most + * significant part is required to be the value of the long double + * rounded to the nearest double, as specified by IEEE. For Inf + * values, the least significant part is required to be one of +0.0 or + * -0.0. No other requirements are made; so, for example, 1.0 may be + * represented as (1.0, +0.0) or (1.0, -0.0), and the low part of a + * NaN is don't-care. + * + * This code currently assumes big-endian. + */ + +#define fabs(x) __builtin_fabs(x) +#define isless(x, y) __builtin_isless(x, y) +#define inf() __builtin_inf() +#define unlikely(x) __builtin_expect((x), 0) +#define nonfinite(a) unlikely(!isless(fabs(a), inf())) + +typedef union { + long double ldval; + double dval[2]; +} longDblUnion; + +/* Add two 'long double' values and return the result. */ +long double __gcc_qadd(double a, double aa, double c, double cc) +{ + longDblUnion x; + double z, q, zz, xh; + + z = a + c; + + if (nonfinite(z)) { + z = cc + aa + c + a; + if (nonfinite(z)) + return z; + x.dval[0] = z; /* Will always be DBL_MAX. */ + zz = aa + cc; + if (fabs(a) > fabs(c)) + x.dval[1] = a - z + c + zz; + else + x.dval[1] = c - z + a + zz; + } else { + q = a - z; + zz = q + c + (a - (q + z)) + aa + cc; + + /* Keep -0 result. */ + if (zz == 0.0) + return z; + + xh = z + zz; + if (nonfinite(xh)) + return xh; + + x.dval[0] = xh; + x.dval[1] = z - xh + zz; + } + return x.ldval; +} + +long double __gcc_qsub(double a, double b, double c, double d) +{ + return __gcc_qadd(a, b, -c, -d); +} + +long double __gcc_qmul(double a, double b, double c, double d) +{ + longDblUnion z; + double t, tau, u, v, w; + + t = a * c; /* Highest order double term. */ + + if (unlikely(t == 0) /* Preserve -0. */ + || nonfinite(t)) + return t; + + /* Sum terms of two highest orders. */ + + /* Use fused multiply-add to get low part of a * c. */ +#ifndef __NO_FPRS__ + asm("fmsub %0,%1,%2,%3" : "=f"(tau) : "f"(a), "f"(c), "f"(t)); +#else + tau = fmsub(a, c, t); +#endif + v = a * d; + w = b * c; + tau += v + w; /* Add in other second-order terms. */ + u = t + tau; + + /* Construct long double result. */ + if (nonfinite(u)) + return u; + z.dval[0] = u; + z.dval[1] = (t - u) + tau; + return z.ldval; +}