Implement 64-bit double functions.

gcc/
	PR target/92055
	* config.gcc (tm_defines) [target=avr]: Support --with-libf7,
	--with-double-comparison.
	* doc/install.texi: Document them.
	* config/avr/avr-c.c (avr_cpu_cpp_builtins)
	<WITH_LIBF7_LIBGCC, WITH_LIBF7_MATH, WITH_LIBF7_MATH_SYMBOLS>
	<WITH_DOUBLE_COMPARISON>: New built-in defines.
	* doc/invoke.texi (AVR Built-in Macros): Document them.
	* config/avr/avr-protos.h (avr_float_lib_compare_returns_bool): New.
	* config/avr/avr.c (avr_float_lib_compare_returns_bool): New function.
	* config/avr/avr.h (FLOAT_LIB_COMPARE_RETURNS_BOOL): New macro.
libgcc/
	PR target/92055
	* config.host (tmake_file) [target=avr]: Add t-libf7,
	t-libf7-math, t-libf7-math-symbols as specified by --with-libf7=.
	* config/avr/t-avrlibc: Don't copy libgcc.a if there are modules
	depending on sizeof (double) or sizeof (long double).
	* config/avr/libf7: New folder.
libgcc/config/avr/libf7/
	PR target/92055
	* t-libf7: New file.
	* t-libf7-math: New file.
	* t-libf7-math-symbols: New file.
	* libf7-common.mk: New file.
	* libf7-asm-object.mk: New file.
	* libf7-c-object.mk: New file.
	* asm-defs.h: New file.
	* libf7.h: New file.
	* libf7.c: New file.
	* libf7-asm.sx: New file.
	* libf7-array.def: New file.
	* libf7-const.def: New file.
	* libf7-constdef.h: New file.
	* f7renames.sh: New script.
	* f7wraps.sh: New script.
	* f7-renames.h: New generated file.
	* f7-wraps.h: New generated file.

From-SVN: r279994

8 files changed, 171 insertions, 10 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b94fb86..12bf61f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,19 @@
+2020-01-08  Georg-Johann Lay  <avr@gjlay.de>
+
+	Implement 64-bit double functions.
+
+	PR target/92055
+	* config.gcc (tm_defines) [target=avr]: Support --with-libf7,
+	--with-double-comparison.
+	* doc/install.texi: Document them.
+	* config/avr/avr-c.c (avr_cpu_cpp_builtins)
+	<WITH_LIBF7_LIBGCC, WITH_LIBF7_MATH, WITH_LIBF7_MATH_SYMBOLS>
+	<WITH_DOUBLE_COMPARISON>: New built-in defines.
+	* doc/invoke.texi (AVR Built-in Macros): Document them.
+	* config/avr/avr-protos.h (avr_float_lib_compare_returns_bool): New.
+	* config/avr/avr.c (avr_float_lib_compare_returns_bool): New function.
+	* config/avr/avr.h (FLOAT_LIB_COMPARE_RETURNS_BOOL): New macro.
+
 2020-01-08  Richard Earnshaw  <rearnsha@arm.com>
 
 	PR target/93188
diff --git a/gcc/config.gcc b/gcc/config.gcc
index c3d6464..6c957c4 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1336,8 +1336,48 @@ avr-*-*)
 	    tm_file="${tm_file} ${cpu_type}/avrlibc.h"
 	    tm_defines="${tm_defines} WITH_AVRLIBC"
 	fi
+	# Work out avr_double_comparison which is 2 or 3 and is used in
+	# target hook FLOAT_LIB_COMPARE_RETURNS_BOOL to determine whether
+	# DFmode comparisons return 3-state or 2-state results.
+	case y${with_double_comparison} in
+	    y | ytristate)
+		avr_double_comparison=3
+		;;
+	    ybool | ylibf7)
+		avr_double_comparison=2
+		;;
+	    *)
+		echo "Error: --with-double-comparison= can only be used with: 'tristate', 'bool', 'libf7'" 1>&2
+		exit 1
+		;;
+	esac
+	case "y${with_libf7}" in
+	    yno)
+		# avr_double_comparison as set above.
+		;;
+	    ylibgcc)
+		avr_double_comparison=2
+		tm_defines="${tm_defines} WITH_LIBF7_LIBGCC"
+		;;
+	    y | yyes | ymath-symbols)
+		avr_double_comparison=2
+		tm_defines="${tm_defines} WITH_LIBF7_LIBGCC"
+		tm_defines="${tm_defines} WITH_LIBF7_MATH"
+		tm_defines="${tm_defines} WITH_LIBF7_MATH_SYMBOLS"
+		;;
+	    ymath)
+		avr_double_comparison=2
+		tm_defines="${tm_defines} WITH_LIBF7_LIBGCC"
+		tm_defines="${tm_defines} WITH_LIBF7_MATH"
+		;;
+	    *)
+		echo "Error: --with-libf7=${with_libf7} but can only be used with: 'libgcc', 'math', 'math-symbols', 'yes', 'no'" 1>&2
+		exit 1
+		;;
+	esac
+	tm_defines="${tm_defines} WITH_DOUBLE_COMPARISON=${avr_double_comparison}"
 	case y${with_double} in
-	    y | y32)
+	    y32)
 		avr_double=32
 		tm_defines="${tm_defines} HAVE_DOUBLE32"
 		;;
@@ -1352,7 +1392,7 @@ avr-*-*)
 		tm_defines="${tm_defines} HAVE_DOUBLE64"
 		tm_defines="${tm_defines} HAVE_DOUBLE_MULTILIB"
 		;;
-	    y32,64)
+	    y | y32,64)
 		avr_double=32
 		avr_double_multilib=1
 		tm_defines="${tm_defines} HAVE_DOUBLE32"
@@ -1365,7 +1405,7 @@ avr-*-*)
 		;;
 	esac
 	case y${with_long_double} in
-	    y | y32)
+	    y32)
 		avr_long_double=32
 		tm_defines="${tm_defines} HAVE_LONG_DOUBLE32"
 		;;
@@ -1373,7 +1413,7 @@ avr-*-*)
 		avr_long_double=64
 		tm_defines="${tm_defines} HAVE_LONG_DOUBLE64"
 		;;
-	    y64,32)
+	    y | y64,32)
 		avr_long_double=64
 		avr_long_double_multilib=1
 		tm_defines="${tm_defines} HAVE_LONG_DOUBLE32"
diff --git a/gcc/config/avr/avr-c.c b/gcc/config/avr/avr-c.c
index 1b75186..35f3e7e 100644
--- a/gcc/config/avr/avr-c.c
+++ b/gcc/config/avr/avr-c.c
@@ -390,6 +390,20 @@ avr_cpu_cpp_builtins (struct cpp_reader *pfile)
   cpp_define (pfile, "__WITH_AVRLIBC__");
 #endif /* WITH_AVRLIBC */
 
+  // From configure --with-libf7={|libgcc|math|math-symbols|yes|no}
+
+#ifdef WITH_LIBF7_LIBGCC
+  cpp_define (pfile, "__WITH_LIBF7_LIBGCC__");
+#endif /* WITH_LIBF7_LIBGCC */
+
+#ifdef WITH_LIBF7_MATH
+  cpp_define (pfile, "__WITH_LIBF7_MATH__");
+#endif /* WITH_LIBF7_MATH */
+
+#ifdef WITH_LIBF7_MATH_SYMBOLS
+  cpp_define (pfile, "__WITH_LIBF7_MATH_SYMBOLS__");
+#endif /* WITH_LIBF7_MATH_SYMBOLS */
+
   // From configure --with-double={|32|32,64|64,32|64}
 
 #ifdef HAVE_DOUBLE_MULTILIB
@@ -438,7 +452,23 @@ avr_cpu_cpp_builtins (struct cpp_reader *pfile)
 #error "align this with config.gcc"
 #endif
 
-  
+  // From configure --with-double-comparison={2|3} --with-libf7.
+
+#if defined (WITH_DOUBLE_COMPARISON)
+#if WITH_DOUBLE_COMPARISON == 2 || WITH_DOUBLE_COMPARISON == 3
+  /* The number of states a DFmode comparison libcall might take and
+     reflects what avr.c:FLOAT_LIB_COMPARE_RETURNS_BOOL returns for
+     DFmode.  GCC's default is 3-state, but some libraries like LibF7
+     implement true / false (2-state).  */
+  cpp_define_formatted (pfile, "__WITH_DOUBLE_COMPARISON__=%d",
+			WITH_DOUBLE_COMPARISON);
+#else
+#error "align this with config.gcc"
+#endif
+#else
+#error "align this with config.gcc"
+#endif
+
   /* Define builtin macros so that the user can easily query whether
      non-generic address spaces (and which) are supported or not.
      This is only supported for C.  For C++, a language extension is needed
diff --git a/gcc/config/avr/avr-protos.h b/gcc/config/avr/avr-protos.h
index d1e4dc5..16c894c 100644
--- a/gcc/config/avr/avr-protos.h
+++ b/gcc/config/avr/avr-protos.h
@@ -128,6 +128,8 @@ extern bool avr_xload_libgcc_p (machine_mode);
 extern rtx avr_eval_addr_attrib (rtx x);
 extern bool avr_casei_sequence_check_operands (rtx *xop);
 
+extern bool avr_float_lib_compare_returns_bool (machine_mode, enum rtx_code);
+
 static inline unsigned
 regmask (machine_mode mode, unsigned regno)
 {
diff --git a/gcc/config/avr/avr.c b/gcc/config/avr/avr.c
index 5ed5b9d..61168ed 100644
--- a/gcc/config/avr/avr.c
+++ b/gcc/config/avr/avr.c
@@ -14575,6 +14575,23 @@ avr_fold_builtin (tree fndecl, int n_args ATTRIBUTE_UNUSED, tree *arg,
   return NULL_TREE;
 }
 
+
+/* Worker function for `FLOAT_LIB_COMPARE_RETURNS_BOOL'.  */
+
+bool
+avr_float_lib_compare_returns_bool (machine_mode mode, enum rtx_code)
+{
+  if (mode == DFmode)
+    {
+#if WITH_DOUBLE_COMPARISON == 2
+      return true;
+#endif
+    }
+
+  // This is the GCC default and also what AVR-LibC implements.
+  return false;
+}
+
 
 
 /* Initialize the GCC target structure.  */
diff --git a/gcc/config/avr/avr.h b/gcc/config/avr/avr.h
index 0900272..c723b8a 100644
--- a/gcc/config/avr/avr.h
+++ b/gcc/config/avr/avr.h
@@ -107,6 +107,9 @@ FIXME: DRIVER_SELF_SPECS has changed.
 #define BYTES_BIG_ENDIAN 0
 #define WORDS_BIG_ENDIAN 0
 
+#define FLOAT_LIB_COMPARE_RETURNS_BOOL(mode, comparison) \
+  avr_float_lib_compare_returns_bool (mode, comparison)
+
 #ifdef IN_LIBGCC2
 /* This is to get correct SI and DI modes in libgcc2.c (32 and 64 bits).  */
 #define UNITS_PER_WORD 4
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 3dee2bb..9001217 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -2309,9 +2309,10 @@ as a multilib option.
 If @option{--with-long-double=double} is specified, @samp{double} and
 @samp{long double} will have the same layout.
 @item
-If the configure option is not set, it defaults to @samp{32} which
-is compatible with older versions of the compiler that use non-standard
-32-bit types for @samp{double} and @samp{long double}.
+The defaults are @option{--with-long-double=64,32} and
+@option{--with-double=32,64}.  The default @samp{double} layout imposed by
+the latter is compatible with older versions of the compiler that implement
+@samp{double} as a 32-bit type, which does not comply to the language standard.
 @end itemize
 Not all combinations of @option{--with-double=} and
 @option{--with-long-double=} are valid.  For example, the combination
@@ -2321,6 +2322,28 @@ multilibs for @samp{double}, whereas the second option implies
 that @samp{long double} --- and hence also @samp{double} --- is always
 32@tie{}bits wide.
 
+@item --with-double-comparison=@{tristate|3|bool|2|libf7@}
+Only supported for the AVR target since version@tie{}10.
+Specify what result format is returned by library functions that
+compare 64-bit floating point values (@code{DFmode}).
+The GCC default is @samp{tristate}.  If the floating point
+implementation returns a boolean instead, set it to @samp{bool}.
+
+@item --with-libf7=@{libgcc|math|math-symbols|no@}
+Only supported for the AVR target since version@tie{}10.
+Specify to which degree code from LibF7 is included in libgcc.
+LibF7 is an ad-hoc, AVR-specific, 64-bit floating point emulation
+written in C and (inline) assembly. @samp{libgcc} adds support
+for functions that one would usually expect in libgcc like double addition,
+double comparisons and double conversions. @samp{math} also adds routines
+that one would expect in @file{libm.a}, but with @code{__} (two underscores)
+prepended to the symbol names as specified by @file{math.h}.
+@samp{math-symbols} also defines weak aliases for the functions
+declared in @file{math.h}.  However, @code{--with-libf7} won't
+install no @file{math.h} header file whatsoever, this file must come
+from elsewhere.  This option sets @option{--with-double-comparison}
+to @samp{bool}.
+
 @item --with-nds32-lib=@var{library}
 Specifies that @var{library} setting is used for building @file{libgcc.a}.
 Currently, the valid @var{library} is @samp{newlib} or @samp{mculib}.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 2b07c09..ea0c42b 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -18421,9 +18421,9 @@ subroutines.  Code size is smaller.
 @opindex mdouble
 @opindex mlong-double
 Set the size (in bits) of the @code{double} or @code{long double} type,
-respectively.  Possible values for @var{bits} are 32 an 64.
+respectively.  Possible values for @var{bits} are 32 and 64.
 Whether or not a specific value for @var{bits} is allowed depends on
-the @code{--with--double=} and @code{--with-long-double=}
+the @code{--with-double=} and @code{--with-long-double=}
 @w{@uref{https://gcc.gnu.org/install/configure.html#avr,configure options}},
 and the same applies for the default values of the options.
 
@@ -18886,6 +18886,36 @@ features like attribute @code{progmem} and @code{pgm_read_*}.
 The compiler is configured to be used together with AVR-Libc.
 See the @option{--with-avrlibc} configure option.
 
+@item __HAVE_DOUBLE_MULTILIB__
+Defined if @option{-mdouble=} acts as a multilib option.
+
+@item __HAVE_DOUBLE32__
+@itemx __HAVE_DOUBLE64__
+Defined if the compiler supports 32-bit double resp. 64-bit double.
+The actual layout is specified by option @option{-mdouble=}.
+
+@item __DEFAULT_DOUBLE__
+The size in bits of @code{double} if @option{-mdouble=} is not set.
+To test the layout of @code{double} in a program, use the built-in
+macro @code{__SIZEOF_DOUBLE__}.
+
+@item __HAVE_LONG_DOUBLE32__
+@itemx __HAVE_LONG_DOUBLE64__
+@itemx __HAVE_LONG_DOUBLE_MULTILIB__
+@itemx __DEFAULT_LONG_DOUBLE__
+Same as above, but for @code{long double} instead of @code{double}.
+
+@item __WITH_DOUBLE_COMPARISON__
+Reflects the @code{--with-double-comparison=@{tristate|bool|libf7@}}
+@w{@uref{https://gcc.gnu.org/install/configure.html#avr,configure option}}
+and is defined to @code{2} or @code{3}.
+
+@item __WITH_LIBF7_LIBGCC__
+@itemx __WITH_LIBF7_MATH__
+@itemx __WITH_LIBF7_MATH_SYMBOLS__
+Reflects the @code{--with-libf7=@{libgcc|math|math-symbols@}}
+@w{@uref{https://gcc.gnu.org/install/configure.html#avr,configure option}}.
+
 @end table
 
 @node Blackfin Options