https://gcc.gnu.org/g:557e809455a886e8f59f57e5c7b0a940e028d130
commit r15-8683-g557e809455a886e8f59f57e5c7b0a940e028d130
Author: Sandra Loosemore <sloosem...@baylibre.com>
Date: Thu Mar 13 03:43:04 2025 +0000
Doc: Add "Additional Numeric Types" sectioning to extend.texi [PR42270]
This is part of an incremental effort to make the chapter on GCC
extensions better organized by grouping/rearranging sections by topic.
gcc/ChangeLog
PR other/42270
* doc/extend.texi (Additional Numeric Types): New section.
(__int128): Make it a subsection of the above.
(Long Long): Likewise.
(Complex): Likewise.
(Floating Types): Likewise.
(Half-Precision): Likewise.
(Decimal Float): Likewise.
(Fixed-Point): Likewise.
Diff:
---
gcc/doc/extend.texi | 94 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 53 insertions(+), 41 deletions(-)
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index b919df914648..92ab031fc904 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -31,14 +31,8 @@ extensions, accepted by GCC in C90 mode and in C++.
* Constructing Calls:: Dispatching a call to another function.
* Typeof:: @code{typeof}: referring to the type of an expression.
* Conditionals:: Omitting the middle operand of a @samp{?:} expression.
-* __int128:: 128-bit integers---@code{__int128}.
-* Long Long:: Double-word integers---@code{long long int}.
-* Complex:: Data types for complex numbers.
-* Floating Types:: Additional Floating Types.
-* Half-Precision:: Half-Precision Floating Point.
-* Decimal Float:: Decimal Floating Types.
+* Additional Numeric Types:: Additional sizes and formats, plus complex
numbers.
* Hex Floats:: Hexadecimal floating-point constants.
-* Fixed-Point:: Fixed-Point Types.
* Named Address Spaces::Named address spaces.
* Zero Length:: Zero-length arrays.
* Empty Structures:: Structures with no members.
@@ -928,8 +922,26 @@ the operand in the middle would perform the side effect
twice. Omitting
the middle operand uses the value already computed without the undesirable
effects of recomputing it.
+@node Additional Numeric Types
+@section Additional Numeric Types
+
+GCC supports additional numeric types, including larger integer types,
+integer and floating-point complex types,
+additional floating-point sizes and formats, decimal floating types,
+and fixed-point types.
+
+@menu
+* __int128:: 128-bit integers---@code{__int128}.
+* Long Long:: Double-word integers---@code{long long int}.
+* Complex:: Data types for complex numbers.
+* Floating Types:: Additional Floating Types.
+* Half-Precision:: Half-Precision Floating Point.
+* Decimal Float:: Decimal Floating Types.
+* Fixed-Point:: Fixed-Point Types.
+@end menu
+
@node __int128
-@section 128-bit Integers
+@subsection 128-bit Integers
@cindex @code{__int128} data types
As an extension the integer scalar type @code{__int128} is supported for
@@ -940,7 +952,7 @@ support in GCC for expressing an integer constant of type
@code{__int128}
for targets with @code{long long} integer less than 128 bits wide.
@node Long Long
-@section Double-Word Integers
+@subsection Double-Word Integers
@cindex @code{long long} data types
@cindex double-word arithmetic
@cindex multiprecision arithmetic
@@ -972,7 +984,7 @@ Likewise, if the function expects @code{long long int} and
you pass
@code{int}. The best way to avoid such problems is to use prototypes.
@node Complex
-@section Complex Numbers
+@subsection Complex Numbers
@cindex complex numbers
@cindex @code{_Complex} keyword
@cindex @code{__complex__} keyword
@@ -1083,7 +1095,7 @@ infinities, NaNs and negative zeros are involved.
@enddefbuiltin
@node Floating Types
-@section Additional Floating Types
+@subsection Additional Floating Types
@cindex additional floating types
@cindex @code{_Float@var{n}} data types
@cindex @code{_Float@var{n}x} data types
@@ -1169,7 +1181,7 @@ typedef _Complex float __attribute__((mode(IC)))
_Complex_ibm128;
@end smallexample
@node Half-Precision
-@section Half-Precision Floating Point
+@subsection Half-Precision Floating Point
@cindex half-precision floating point
@cindex @code{__fp16} data type
@cindex @code{__Float16} data type
@@ -1240,7 +1252,7 @@ It is useful for code that does not have @code{_Float16}
and runs on the x87
FPU.
@node Decimal Float
-@section Decimal Floating Types
+@subsection Decimal Floating Types
@cindex decimal floating types
@cindex @code{_Decimal32} data type
@cindex @code{_Decimal64} data type
@@ -1292,35 +1304,8 @@ the technical report.
Types @code{_Decimal32}, @code{_Decimal64}, and @code{_Decimal128}
are supported by the DWARF debug information format.
-@node Hex Floats
-@section Hex Floats
-@cindex hex floats
-
-ISO C99 and ISO C++17 support floating-point numbers written not only in
-the usual decimal notation, such as @code{1.55e1}, but also numbers such as
-@code{0x1.fp3} written in hexadecimal format. As a GNU extension, GCC
-supports this in C90 mode (except in some cases when strictly
-conforming) and in C++98, C++11 and C++14 modes. In that format the
-@samp{0x} hex introducer and the @samp{p} or @samp{P} exponent field are
-mandatory. The exponent is a decimal number that indicates the power of
-2 by which the significant part is multiplied. Thus @samp{0x1.f} is
-@tex
-$1 {15\over16}$,
-@end tex
-@ifnottex
-1 15/16,
-@end ifnottex
-@samp{p3} multiplies it by 8, and the value of @code{0x1.fp3}
-is the same as @code{1.55e1}.
-
-Unlike for floating-point numbers in the decimal notation the exponent
-is always required in the hexadecimal notation. Otherwise the compiler
-would not be able to resolve the ambiguity of, e.g., @code{0x1.f}. This
-could mean @code{1.0f} or @code{1.9375} since @samp{f} is also the
-extension for floating-point constants of type @code{float}.
-
@node Fixed-Point
-@section Fixed-Point Types
+@subsection Fixed-Point Types
@cindex fixed-point types
@cindex @code{_Fract} data type
@cindex @code{_Accum} data type
@@ -1466,6 +1451,33 @@ Pragmas to control overflow and rounding behaviors are
not implemented.
Fixed-point types are supported by the DWARF debug information format.
+@node Hex Floats
+@section Hex Floats
+@cindex hex floats
+
+ISO C99 and ISO C++17 support floating-point numbers written not only in
+the usual decimal notation, such as @code{1.55e1}, but also numbers such as
+@code{0x1.fp3} written in hexadecimal format. As a GNU extension, GCC
+supports this in C90 mode (except in some cases when strictly
+conforming) and in C++98, C++11 and C++14 modes. In that format the
+@samp{0x} hex introducer and the @samp{p} or @samp{P} exponent field are
+mandatory. The exponent is a decimal number that indicates the power of
+2 by which the significant part is multiplied. Thus @samp{0x1.f} is
+@tex
+$1 {15\over16}$,
+@end tex
+@ifnottex
+1 15/16,
+@end ifnottex
+@samp{p3} multiplies it by 8, and the value of @code{0x1.fp3}
+is the same as @code{1.55e1}.
+
+Unlike for floating-point numbers in the decimal notation the exponent
+is always required in the hexadecimal notation. Otherwise the compiler
+would not be able to resolve the ambiguity of, e.g., @code{0x1.f}. This
+could mean @code{1.0f} or @code{1.9375} since @samp{f} is also the
+extension for floating-point constants of type @code{float}.
+
@node Named Address Spaces
@section Named Address Spaces
@cindex Named Address Spaces
