@@ -1076,9 +1076,11 @@ systems where @code{__float128} is supported. The @code{_Float32}
type is supported on all systems supporting IEEE binary32; the
@code{_Float64} and @code{_Float32x} types are supported on all systems
supporting IEEE binary64. The @code{_Float16} type is supported on AArch64
-systems by default, and on ARM systems when the IEEE format for 16-bit
-floating-point types is selected with @option{-mfp16-format=ieee}.
-GCC does not currently support @code{_Float128x} on any systems.
+systems by default, and also on x86 systems with @code{target("sse2")}
+for both C and C++.
+On ARM systems when the IEEE format for 16-bit floating-point types is
+selected with @option{-mfp16-format=ieee}. GCC does not currently support
+@code{_Float128x} on any systems.
On the i386, x86_64, IA-64, and HP-UX targets, you can declare complex
types using the corresponding internal complex type, @code{XCmode} for
@@ -1108,6 +1110,10 @@ On ARM and AArch64 targets, GCC supports half-precision (16-bit) floating
point via the @code{__fp16} type defined in the ARM C Language Extensions.
On ARM systems, you must enable this type explicitly with the
@option{-mfp16-format} command-line option in order to use it.
+On x86 targets with @code{target("sse2")} and above, GCC supports
+half-precision (16-bit) floating point via the @code{_Float16} type.
+For C++, x86 provide a builtin type named @code{_Float16} which contains
+same data format as C.
ARM targets support two incompatible representations for half-precision
floating-point values. You must choose one of the representations and
@@ -1151,16 +1157,11 @@ calls.
It is recommended that portable code use the @code{_Float16} type defined
by ISO/IEC TS 18661-3:2015. @xref{Floating Types}.
-On x86 targets with @code{target("sse2")} and above, GCC supports half-precision
-(16-bit) floating point via the @code{_Float16} type which is defined by
-18661-3:2015. For C++, x86 provide a builtin type named @code{_Float16}
-which contains same data format as C.
-
-Without @option{-mavx512fp16}, @code{_Float16} type is storage only, all
-operations will be emulated by software emulation and the @code{float}
-instructions. The default behavior for @code{FLT_EVAL_METHOD} is to keep
-the intermediate result of the operation as 32-bit precision. This may lead
-to inconsistent behavior between software emulation and AVX512-FP16
+On x86 targets, without @option{-mavx512fp16}, @code{_Float16} type is
+storage only, all operations will be emulated by software emulation and the
+@code{float} instructions. The default behavior for @code{FLT_EVAL_METHOD} is
+to keep the intermediate result of the operation as 32-bit precision. This may
+lead to inconsistent behavior between software emulation and AVX512-FP16
instructions.
@node Decimal Float
Hi: As discussed in [1], adjust the layout for x86 _Float16 description. Bootstrappedn and regtested on x86_64-linux-gnu{-m32,}. Ok for trunk? gcc/ChangeLog: * doc/extend.texi: (@node Floating Types): Adjust the wording. (@node Half-Precision): Ditto. --- gcc/doc/extend.texi | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-)