Replace {FLOAT,{,LONG_}DOUBLE}_TYPE_SIZE with new hook mode_for_floating_type

Currently how we determine which mode will be used for a
floating point type is that for a given type precision
(size) call mode_for_size to get the first mode which has
this size in the specified class.  On Powerpc, we have
three modes (TF/KF/IF) having the same mode precision 128
(see[1]), so the processing forces us to have to place TF
at the first place, it would require us to make more
adjustment in some generic code to avoid some unexpected
mode conversions and it would be even worse if we get rid
of TF eventually one day.  And as Joseph pointed out in [2],
"floating  types should have their mode, not a poorly
defined precision value", as Joseph and Richi suggested,
this patch is to introduce one hook mode_for_floating_type
which returns the corresponding mode for type float, double
or long double.  The default implementation returns SFmode
for float and DFmode for double or long double.  For ports
which need special treatment, there are some other patches
for their own port specific implementation (referring to
how {,LONG_}DOUBLE_TYPE_SIZE get used there).  For all
generic uses of {FLOAT,{,LONG_}DOUBLE}_TYPE_SIZE, depending
on the context, some of them are replaced with TYPE_PRECISION
of the according type node, some other are replaced with
GET_MODE_PRECISION on the mode from mode_for_floating_type.
This patch also poisons {FLOAT,{,LONG_}DOUBLE}_TYPE_SIZE,
so most defines of {FLOAT,{,LONG_}DOUBLE}_TYPE_SIZE in port
specific are removed, but there are still some which are
good to be kept for readability then they get renamed with
port specific prefix.

[1] https://gcc.gnu.org/pipermail/gcc-patches/2024-May/651017.html
[2] https://gcc.gnu.org/pipermail/gcc-patches/2024-May/651209.html

gcc/jit/ChangeLog:

	* jit-recording.cc (recording::memento_of_get_type::get_size): Update
	macros {FLOAT,DOUBLE,LONG_DOUBLE}_TYPE_SIZE by calling
	targetm.c.mode_for_floating_type with
	TI_{FLOAT,DOUBLE,LONG_DOUBLE}_TYPE.

gcc/ChangeLog:

	* coretypes.h (enum tree_index): Forward declaration.
	* defaults.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* doc/rtl.texi: Update document by replacing {FLOAT,DOUBLE}_TYPE_SIZE
	with C type {float,double}.
	* doc/tm.texi.in: Document new hook mode_for_floating_type, remove
	document entries for {FLOAT,DOUBLE,LONG_DOUBLE}_TYPE_SIZE and
	update document for WIDEST_HARDWARE_FP_SIZE.
	* doc/tm.texi: Regenerate.
	* emit-rtl.cc (init_emit_once): Replace DOUBLE_TYPE_SIZE by
	calling targetm.c.mode_for_floating_type with TI_DOUBLE_TYPE.
	* real.h (REAL_VALUE_TO_TARGET_LONG_DOUBLE): Use TYPE_PRECISION of
	long_double_type_node to replace LONG_DOUBLE_TYPE_SIZE.
	* system.h (FLOAT_TYPE_SIZE): Poison.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* target.def (mode_for_floating_type): New hook.
	* targhooks.cc (default_mode_for_floating_type): New function.
	(default_scalar_mode_supported_p): Update macros
	{FLOAT,DOUBLE,LONG_DOUBLE}_TYPE_SIZE by calling
	targetm.c.mode_for_floating_type with
	TI_{FLOAT,DOUBLE,LONG_DOUBLE}_TYPE.
	* targhooks.h (default_mode_for_floating_type): New declaration.
	* tree-core.h (enum tree_index): Specify underlying type unsigned
	to sync with forward declaration in coretypes.h.
	(NUM_FLOATN_TYPES): Explicitly convert to int.
	(NUM_FLOATNX_TYPES): Likewise.
	(NUM_FLOATN_NX_TYPES): Likewise.
	* tree.cc (build_common_tree_nodes): Update macros
	{FLOAT,DOUBLE,LONG_DOUBLE}_TYPE_SIZE by calling
	targetm.c.mode_for_floating_type with
	TI_{FLOAT,DOUBLE,LONG_DOUBLE}_TYPE and set type mode accordingly.
	* config/arc/arc.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/bpf/bpf.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/epiphany/epiphany.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/fr30/fr30.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/frv/frv.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/ft32/ft32.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/gcn/gcn.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/iq2000/iq2000.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/lm32/lm32.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/m32c/m32c.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/m32r/m32r.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/microblaze/microblaze.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/mmix/mmix.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/moxie/moxie.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/msp430/msp430.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/nds32/nds32.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/nios2/nios2.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/nvptx/nvptx.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/or1k/or1k.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/pdp11/pdp11.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/pru/pru.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/stormy16/stormy16.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/visium/visium.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/xtensa/xtensa.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/rs6000/rs6000.cc (TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	(rs6000_c_mode_for_floating_type): New function.
	* config/rs6000/rs6000.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/aarch64/aarch64.cc (aarch64_c_mode_for_floating_type):
	New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/aarch64/aarch64.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/alpha/alpha.cc (alpha_c_mode_for_floating_type): New
	function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/alpha/alpha.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/avr/avr.cc (avr_c_mode_for_floating_type): New
	function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/avr/avr.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/i386/i386.cc (ix86_c_mode_for_floating_type): New
	function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/i386/i386.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/ia64/ia64.cc (ia64_c_mode_for_floating_type): New
	function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/ia64/ia64.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/riscv/riscv.cc (riscv_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/riscv/riscv.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/rl78/rl78.cc (TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	(rl78_c_mode_for_floating_type): New function.
	* config/rl78/rl78.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/rx/rx.cc (rx_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/rx/rx.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/s390/s390.cc (s390_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/s390/s390.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/sh/sh.cc (sh_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/sh/sh.h (LONG_DOUBLE_TYPE_SIZE): Remove.
	* config/h8300/h8300.cc (h8300_c_mode_for_floating_type): New
	function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/h8300/h8300.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Remove.
	(LONG_DOUBLE_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_MODE): New macro.
	* config/h8300/linux.h (DOUBLE_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_MODE): New macro.
	* config/loongarch/loongarch.cc (loongarch_c_mode_for_floating_type):
	New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/loongarch/loongarch.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Remove.
	(LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(LA_LONG_DOUBLE_TYPE_SIZE): ... this.
	(UNITS_PER_FPVALUE): Replace LONG_DOUBLE_TYPE_SIZE with
	LA_LONG_DOUBLE_TYPE_SIZE.
	(MAX_FIXED_MODE_SIZE): Likewise.
	(STRUCTURE_SIZE_BOUNDARY): Likewise.
	(BIGGEST_ALIGNMENT): Likewise.
	* config/m68k/m68k.cc (m68k_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/m68k/m68k.h (LONG_DOUBLE_TYPE_SIZE): Remove.
	(LONG_DOUBLE_TYPE_MODE): New macro.
	* config/m68k/netbsd-elf.h (LONG_DOUBLE_TYPE_SIZE): Remove.
	(LONG_DOUBLE_TYPE_MODE): New macro.
	* config/mips/mips.cc (mips_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	* config/mips/mips.h (UNITS_PER_FPVALUE): Replace LONG_DOUBLE_TYPE_SIZE
	with MIPS_LONG_DOUBLE_TYPE_SIZE.
	(MAX_FIXED_MODE_SIZE): Likewise.
	(STRUCTURE_SIZE_BOUNDARY): Likewise.
	(BIGGEST_ALIGNMENT): Likewise.
	(FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Remove.
	(LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(MIPS_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/mips/n32-elf.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(MIPS_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/pa/pa.cc (pa_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	(pa_scalar_mode_supported_p): Rename FLOAT_TYPE_SIZE to
	PA_FLOAT_TYPE_SIZE, rename DOUBLE_TYPE_SIZE to PA_DOUBLE_TYPE_SIZE
	and rename LONG_DOUBLE_TYPE_SIZE to PA_LONG_DOUBLE_TYPE_SIZE.
	* config/pa/pa.h (PA_FLOAT_TYPE_SIZE): New macro.
	(PA_DOUBLE_TYPE_SIZE): Likewise.
	(PA_LONG_DOUBLE_TYPE_SIZE): Likewise.
	* config/pa/pa-64.h (FLOAT_TYPE_SIZE): Rename to ...
	(PA_FLOAT_TYPE_SIZE): ... this.
	(DOUBLE_TYPE_SIZE): Rename to ...
	(PA_DOUBLE_TYPE_SIZE): ... this.
	(LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(PA_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/pa/pa-hpux.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(PA_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/sparc.cc (sparc_c_mode_for_floating_type): New function.
	(TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
	(FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Likewise.
	(LONG_DOUBLE_TYPE_SIZE): Likewise.
	(sparc_type_code): Replace FLOAT_TYPE_SIZE with TYPE_PRECISION of
	float_type_node.
	* config/sparc/sparc.h (FLOAT_TYPE_SIZE): Remove.
	(DOUBLE_TYPE_SIZE): Remove.
	* config/sparc/freebsd.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/linux.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/linux64.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/netbsd-elf.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/openbsd64.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/sol2.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/sp-elf.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/sparc/sp64-elf.h (LONG_DOUBLE_TYPE_SIZE): Rename to ...
	(SPARC_LONG_DOUBLE_TYPE_SIZE): ... this.
	* config/bfin/bfin.h (FLOAT_TYPE_SIZE): Rename to ...
	(BFIN_FLOAT_TYPE_SIZE): ... this.
	(DOUBLE_TYPE_SIZE): Rename to ...
	(BFIN_DOUBLE_TYPE_SIZE): ... this.
	(LONG_DOUBLE_TYPE_SIZE): Remove.
	(UNITS_PER_FLOAT): Replace FLOAT_TYPE_SIZE with BFIN_FLOAT_TYPE_SIZE.
	(UNITS_PER_DOUBLE): Replace DOUBLE_TYPE_SIZE with
	BFIN_DOUBLE_TYPE_SIZE.

3 files changed, 21 insertions, 41 deletions

diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index 846a043..c1717ab 100644
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -1326,7 +1326,7 @@ whose size is @code{BITS_PER_WORD}, @code{SImode} on 32-bit machines.
 
 The only modes which a machine description @i{must} support are
 @code{QImode}, and the modes corresponding to @code{BITS_PER_WORD},
-@code{FLOAT_TYPE_SIZE} and @code{DOUBLE_TYPE_SIZE}.
+C type @code{float} and C type @code{double}.
 The compiler will attempt to use @code{DImode} for 8-byte structures and
 unions, but this can be prevented by overriding the definition of
 @code{MAX_FIXED_MODE_SIZE}.  Alternatively, you can have the compiler
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index be5543b..24c92e2 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -1044,6 +1044,14 @@ are zero or sign extended depending on if it is
 @code{GET_MODE_ALIGNMENT (info->limb_mode)}.
 @end deftypefn
 
+@deftypefn {Target Hook} machine_mode TARGET_C_MODE_FOR_FLOATING_TYPE (enum tree_index @var{ti})
+Return machine mode for a C floating point type which is indicated by
+ a given @code{enum tree_index} @var{ti}, @var{ti} should be
+ @code{TI_FLOAT_TYPE}, @code{TI_DOUBLE_TYPE} or @code{TI_LONG_DOUBLE_TYPE}.
+ The default implementation returns @code{SFmode} for @code{TI_FLOAT_TYPE},
+ and @code{DFmode} for @code{TI_DOUBLE_TYPE} or @code{TI_LONG_DOUBLE_TYPE}.
+@end deftypefn
+
 @deftypefn {Target Hook} machine_mode TARGET_PROMOTE_FUNCTION_MODE (const_tree @var{type}, machine_mode @var{mode}, int *@var{punsignedp}, const_tree @var{funtype}, int @var{for_return})
 Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or
 function return values.  The target hook should return the new mode
@@ -1610,23 +1618,6 @@ C99 type @code{_Bool} on the target machine.  If you don't define
 this, and you probably shouldn't, the default is @code{CHAR_TYPE_SIZE}.
 @end defmac
 
-@defmac FLOAT_TYPE_SIZE
-A C expression for the size in bits of the type @code{float} on the
-target machine.  If you don't define this, the default is one word.
-@end defmac
-
-@defmac DOUBLE_TYPE_SIZE
-A C expression for the size in bits of the type @code{double} on the
-target machine.  If you don't define this, the default is two
-words.
-@end defmac
-
-@defmac LONG_DOUBLE_TYPE_SIZE
-A C expression for the size in bits of the type @code{long double} on
-the target machine.  If you don't define this, the default is two
-words.
-@end defmac
-
 @defmac SHORT_FRACT_TYPE_SIZE
 A C expression for the size in bits of the type @code{short _Fract} on
 the target machine.  If you don't define this, the default is
@@ -1687,9 +1678,11 @@ the libgcc @file{config.host}.
 @defmac WIDEST_HARDWARE_FP_SIZE
 A C expression for the size in bits of the widest floating-point format
 supported by the hardware.  If you define this macro, you must specify a
-value less than or equal to the value of @code{LONG_DOUBLE_TYPE_SIZE}.
-If you do not define this macro, the value of @code{LONG_DOUBLE_TYPE_SIZE}
-is the default.
+value less than or equal to mode precision of the mode used for C type
+@code{long double} (from hook @code{targetm.c.mode_for_floating_type}
+with argument @code{TI_LONG_DOUBLE_TYPE}).  If you do not define this
+macro, mode precision of the mode used for C type @code{long double} is
+the default.
 @end defmac
 
 @defmac DEFAULT_SIGNED_CHAR
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 87a7f89..24596eb 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -947,6 +947,8 @@ applied.
 
 @hook TARGET_C_BITINT_TYPE_INFO
 
+@hook TARGET_C_MODE_FOR_FLOATING_TYPE
+
 @hook TARGET_PROMOTE_FUNCTION_MODE
 
 @defmac PARM_BOUNDARY
@@ -1351,23 +1353,6 @@ C99 type @code{_Bool} on the target machine.  If you don't define
 this, and you probably shouldn't, the default is @code{CHAR_TYPE_SIZE}.
 @end defmac
 
-@defmac FLOAT_TYPE_SIZE
-A C expression for the size in bits of the type @code{float} on the
-target machine.  If you don't define this, the default is one word.
-@end defmac
-
-@defmac DOUBLE_TYPE_SIZE
-A C expression for the size in bits of the type @code{double} on the
-target machine.  If you don't define this, the default is two
-words.
-@end defmac
-
-@defmac LONG_DOUBLE_TYPE_SIZE
-A C expression for the size in bits of the type @code{long double} on
-the target machine.  If you don't define this, the default is two
-words.
-@end defmac
-
 @defmac SHORT_FRACT_TYPE_SIZE
 A C expression for the size in bits of the type @code{short _Fract} on
 the target machine.  If you don't define this, the default is
@@ -1428,9 +1413,11 @@ the libgcc @file{config.host}.
 @defmac WIDEST_HARDWARE_FP_SIZE
 A C expression for the size in bits of the widest floating-point format
 supported by the hardware.  If you define this macro, you must specify a
-value less than or equal to the value of @code{LONG_DOUBLE_TYPE_SIZE}.
-If you do not define this macro, the value of @code{LONG_DOUBLE_TYPE_SIZE}
-is the default.
+value less than or equal to mode precision of the mode used for C type
+@code{long double} (from hook @code{targetm.c.mode_for_floating_type}
+with argument @code{TI_LONG_DOUBLE_TYPE}).  If you do not define this
+macro, mode precision of the mode used for C type @code{long double} is
+the default.
 @end defmac
 
 @defmac DEFAULT_SIGNED_CHAR