## Submitted:## Dimitry Andric <dimitry@andric.com>, 2004-05-01## Description:## Nicholas Pitre released this patch for gcc soft-float support here: # http://lists.arm.linux.org.uk/pipermail/linux-arm/2003-October/006436.html## This version has been adapted to work with gcc 3.4.0.## The original patch doesn't distinguish between softfpa and softvfp modes# in the way Nicholas Pitre probably meant.  His description is:## "Default is to use APCS-32 mode with soft-vfp.  The old Linux default for# floats can be achieved with -mhard-float or with the configure# --with-float=hard option.  If -msoft-float or --with-float=soft is used then# software float support will be used just like the default but with the legacy# big endian word ordering for double float representation instead."## Which means the following:## * If you compile without -mhard-float or -msoft-float, you should get#   software floating point, using the VFP format.  The produced object file#   should have these flags in its header:##     private flags = 600: [APCS-32] [VFP float format] [software FP]## * If you compile with -mhard-float, you should get hardware floating point,#   which always uses the FPA format.  Object file header flags should be:##     private flags = 0: [APCS-32] [FPA float format]## * If you compile with -msoft-float, you should get software floating point,#   using the FPA format.  This is done for compatibility reasons with many#   existing distributions.  Object file header flags should be:##     private flags = 200: [APCS-32] [FPA float format] [software FP]## The original patch from Nicholas Pitre contained the following constructs:##   #define SUBTARGET_EXTRA_ASM_SPEC "%{!mcpu=*:-mcpu=xscale} \#     %{mhard-float:-mfpu=fpa} \#     %{!mhard-float: %{msoft-float:-mfpu=softfpa;:-mfpu=softvfp}}"## However, gcc doesn't accept this ";:" notation, used in the 3rd line.  This# is probably the reason Robert Schwebel modified it to:##   #define SUBTARGET_EXTRA_ASM_SPEC "%{!mcpu=*:-mcpu=xscale} \#     %{mhard-float:-mfpu=fpa} \#     %{!mhard-float: %{msoft-float:-mfpu=softfpa -mfpu=softvfp}}"## But this causes the following behaviour:## * If you compile without -mhard-float or -msoft-float, the compiler generates#   software floating point instructions, but *nothing* is passed to the#   assembler, which results in an object file which has flags:##     private flags = 0: [APCS-32] [FPA float format]##   This is not correct!## * If you compile with -mhard-float, the compiler generates hardware floating#   point instructions, and passes "-mfpu=fpa" to the assembler, which results#   in an object file which has the same flags as in the previous item, but now#   those *are* correct.#    # * If you compile with -msoft-float, the compiler generates software floating#   point instructions, and passes "-mfpu=softfpa -mfpu=softvfp" (in that#   order) to the assembler, which results in an object file with flags:##   private flags = 600: [APCS-32] [VFP float format] [software FP]##   This is not correct, because the last "-mfpu=" option on the assembler#   command line determines the actual FPU convention used (which should be FPA#   in this case).## Therefore, I modified this patch to get the desired behaviour.  Every# instance of the notation:##   %{msoft-float:-mfpu=softfpa -mfpu=softvfp}## was changed to:##   %{msoft-float:-mfpu=softfpa} %{!msoft-float:-mfpu=softvfp}## I also did the following:# # * Modified all TARGET_DEFAULT macros I could find to include ARM_FLAG_VFP, to#   be consistent with Nicholas' original patch.# * Removed any "msoft-float" or "mhard-float" from all MULTILIB_DEFAULTS#   macros I could find.  I think that if you compile without any options, you#   would like to get the defaults. :)# * Removed the extra -lfloat option from LIBGCC_SPEC, since it isn't needed#   anymore.  (The required functions are now in libgcc.)diff -urNd gcc-3.4.0-orig/gcc/config/arm/coff.h gcc-3.4.0/gcc/config/arm/coff.h--- gcc-3.4.0-orig/gcc/config/arm/coff.h	2004-02-24 15:25:22.000000000 +0100+++ gcc-3.4.0/gcc/config/arm/coff.h	2004-05-01 19:07:06.059409600 +0200@@ -31,11 +31,16 @@ #define TARGET_VERSION fputs (" (ARM/coff)", stderr)  #undef  TARGET_DEFAULT-#define TARGET_DEFAULT (ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_32 | ARM_FLAG_APCS_FRAME | ARM_FLAG_MMU_TRAPS)+#define TARGET_DEFAULT		\+	( ARM_FLAG_SOFT_FLOAT	\+	| ARM_FLAG_VFP		\+	| ARM_FLAG_APCS_32	\+	| ARM_FLAG_APCS_FRAME	\+	| ARM_FLAG_MMU_TRAPS )  #ifndef MULTILIB_DEFAULTS #define MULTILIB_DEFAULTS \-  { "marm", "mlittle-endian", "msoft-float", "mapcs-32", "mno-thumb-interwork" }+  { "marm", "mlittle-endian", "mapcs-32", "mno-thumb-interwork" } #endif  /* This is COFF, but prefer stabs.  */diff -urNd gcc-3.4.0-orig/gcc/config/arm/elf.h gcc-3.4.0/gcc/config/arm/elf.h--- gcc-3.4.0-orig/gcc/config/arm/elf.h	2004-02-24 15:25:22.000000000 +0100+++ gcc-3.4.0/gcc/config/arm/elf.h	2004-05-01 19:12:16.976486400 +0200@@ -46,7 +46,9 @@  #ifndef SUBTARGET_ASM_FLOAT_SPEC #define SUBTARGET_ASM_FLOAT_SPEC "\-%{mapcs-float:-mfloat} %{msoft-float:-mfpu=softfpa}"+%{mapcs-float:-mfloat} \+%{mhard-float:-mfpu=fpa} \+%{!mhard-float: %{msoft-float:-mfpu=softfpa} %{!msoft-float:-mfpu=softvfp}}" #endif  #ifndef ASM_SPEC@@ -106,12 +108,17 @@ #endif  #ifndef TARGET_DEFAULT-#define TARGET_DEFAULT (ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_32 | ARM_FLAG_APCS_FRAME | ARM_FLAG_MMU_TRAPS)+#define TARGET_DEFAULT		\+	( ARM_FLAG_SOFT_FLOAT	\+	| ARM_FLAG_VFP		\+	| ARM_FLAG_APCS_32	\+	| ARM_FLAG_APCS_FRAME	\+	| ARM_FLAG_MMU_TRAPS ) #endif  #ifndef MULTILIB_DEFAULTS #define MULTILIB_DEFAULTS \-  { "marm", "mlittle-endian", "msoft-float", "mapcs-32", "mno-thumb-interwork", "fno-leading-underscore" }+  { "marm", "mlittle-endian", "mapcs-32", "mno-thumb-interwork", "fno-leading-underscore" } #endif  #define TARGET_ASM_FILE_START_APP_OFF truediff -urNd gcc-3.4.0-orig/gcc/config/arm/linux-elf.h gcc-3.4.0/gcc/config/arm/linux-elf.h--- gcc-3.4.0-orig/gcc/config/arm/linux-elf.h	2004-01-31 07:18:11.000000000 +0100+++ gcc-3.4.0/gcc/config/arm/linux-elf.h	2004-05-01 19:19:06.935979200 +0200@@ -30,9 +30,27 @@ /* Do not assume anything about header files.  */ #define NO_IMPLICIT_EXTERN_C -/* Default is to use APCS-32 mode.  */+/*+ * Default is to use APCS-32 mode with soft-vfp.+ * The old Linux default for floats can be achieved with -mhard-float+ * or with the configure --with-float=hard option.+ * If -msoft-float or --with-float=soft is used then software float + * support will be used just like the default but with the legacy+ * big endian word ordering for double float representation instead.+ */+ #undef  TARGET_DEFAULT-#define TARGET_DEFAULT (ARM_FLAG_APCS_32 | ARM_FLAG_MMU_TRAPS)+#define TARGET_DEFAULT		\+	( ARM_FLAG_APCS_32	\+	| ARM_FLAG_SOFT_FLOAT	\+	| ARM_FLAG_VFP		\+	| ARM_FLAG_MMU_TRAPS )++#undef  SUBTARGET_EXTRA_ASM_SPEC+#define SUBTARGET_EXTRA_ASM_SPEC "\+%{!mcpu=*:-mcpu=xscale} \+%{mhard-float:-mfpu=fpa} \+%{!mhard-float: %{msoft-float:-mfpu=softfpa} %{!msoft-float:-mfpu=softvfp}}"  #define SUBTARGET_CPU_DEFAULT TARGET_CPU_arm6 @@ -40,7 +58,7 @@  #undef  MULTILIB_DEFAULTS #define MULTILIB_DEFAULTS \-	{ "marm", "mlittle-endian", "mhard-float", "mapcs-32", "mno-thumb-interwork" }+	{ "marm", "mlittle-endian", "mapcs-32", "mno-thumb-interwork" }  #define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__" @@ -55,7 +73,7 @@    %{shared:-lc} \    %{!shared:%{profile:-lc_p}%{!profile:-lc}}" -#define LIBGCC_SPEC "%{msoft-float:-lfloat} -lgcc"+#define LIBGCC_SPEC "-lgcc"  /* Provide a STARTFILE_SPEC appropriate for GNU/Linux.  Here we add    the GNU/Linux magical crtbegin.o file (see crtstuff.c) whichdiff -urNd gcc-3.4.0-orig/gcc/config/arm/t-linux gcc-3.4.0/gcc/config/arm/t-linux--- gcc-3.4.0-orig/gcc/config/arm/t-linux	2003-09-20 23:09:07.000000000 +0200+++ gcc-3.4.0/gcc/config/arm/t-linux	2004-05-01 20:31:59.102846400 +0200@@ -4,7 +4,10 @@ LIBGCC2_DEBUG_CFLAGS = -g0  LIB1ASMSRC = arm/lib1funcs.asm-LIB1ASMFUNCS = _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_lnx+LIB1ASMFUNCS = _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_lnx \+	_negdf2 _addsubdf3 _muldivdf3 _cmpdf2 _unorddf2 _fixdfsi _fixunsdfsi \+	_truncdfsf2 _negsf2 _addsubsf3 _muldivsf3 _cmpsf2 _unordsf2 \+	_fixsfsi _fixunssfsi  # MULTILIB_OPTIONS = mhard-float/msoft-float # MULTILIB_DIRNAMES = hard-float soft-floatdiff -urNd gcc-3.4.0-orig/gcc/config/arm/unknown-elf.h gcc-3.4.0/gcc/config/arm/unknown-elf.h--- gcc-3.4.0-orig/gcc/config/arm/unknown-elf.h	2004-02-24 15:25:22.000000000 +0100+++ gcc-3.4.0/gcc/config/arm/unknown-elf.h	2004-05-01 19:09:09.016212800 +0200@@ -30,7 +30,12 @@  /* Default to using APCS-32 and software floating point.  */ #ifndef TARGET_DEFAULT-#define TARGET_DEFAULT	(ARM_FLAG_SOFT_FLOAT | ARM_FLAG_APCS_32 | ARM_FLAG_APCS_FRAME | ARM_FLAG_MMU_TRAPS)+#define TARGET_DEFAULT		\+	( ARM_FLAG_SOFT_FLOAT	\+	| ARM_FLAG_VFP		\+	| ARM_FLAG_APCS_32	\+	| ARM_FLAG_APCS_FRAME	\+	| ARM_FLAG_MMU_TRAPS ) #endif  /* Now we define the strings used to build the spec file.  */diff -urNd gcc-3.4.0-orig/gcc/config/arm/xscale-elf.h gcc-3.4.0/gcc/config/arm/xscale-elf.h--- gcc-3.4.0-orig/gcc/config/arm/xscale-elf.h	2003-07-02 01:26:43.000000000 +0200+++ gcc-3.4.0/gcc/config/arm/xscale-elf.h	2004-05-01 20:15:36.620105600 +0200@@ -49,11 +49,12 @@ 		     endian, regardless of the endian-ness of the memory 		     system.  */ 		     -#define SUBTARGET_EXTRA_ASM_SPEC "%{!mcpu=*:-mcpu=xscale} \-  %{mhard-float:-mfpu=fpa} \-  %{!mhard-float: %{msoft-float:-mfpu=softfpa;:-mfpu=softvfp}}"+#define SUBTARGET_EXTRA_ASM_SPEC "\+%{!mcpu=*:-mcpu=xscale} \+%{mhard-float:-mfpu=fpa} \+%{!mhard-float: %{msoft-float:-mfpu=softfpa} %{!msoft-float:-mfpu=softvfp}}"  #ifndef MULTILIB_DEFAULTS #define MULTILIB_DEFAULTS \-  { "mlittle-endian", "mno-thumb-interwork", "marm", "msoft-float" }+  { "mlittle-endian", "mno-thumb-interwork", "marm" } #endif