From aa0235dfdebffe9b338deba51f3ba563ee9b433d Mon Sep 17 00:00:00 2001 From: "Gabriel F. T. Gomes" Date: Mon, 2 Oct 2017 14:46:35 -0300 Subject: Add C++ versions of iscanonical for ldbl-96 and ldbl-128ibm (bug 22235) All representations of floating-point numbers in types with IEC 60559 binary exchange format are canonical. On the other hand, types with IEC 60559 extended formats, such as those implemented under ldbl-96 and ldbl-128ibm, contain representations that are not canonical. TS 18661-1 introduced the type-generic macro iscanonical, which returns whether a floating-point value is canonical or not. In Glibc, this type-generic macro is implemented using the macro __MATH_TG, which, when support for float128 is enabled, relies on __builtin_types_compatible_p to select between floating-point types. However, this use of iscanonical breaks C++ applications, because the builtin is only available in C mode. This patch provides a C++ implementation of iscanonical that relies on function overloading, rather than builtins, to select between floating-point types. Unlike the C++ implementations for iszero and issignaling, this implementation ignores __NO_LONG_DOUBLE_MATH. The double type always matches IEC 60559 double format, which is always canonical. Thus, when double and long double are the same (__NO_LONG_DOUBLE_MATH), iscanonical always returns 1 and is not implemented with __MATH_TG. Tested for powerpc64, powerpc64le and x86_64. [BZ #22235] * math/math.h: Trivial fix for unbalanced parentheses in comment. * math/Makefile [CXX] (tests): Add test-math-iscanonical.cc. (CFLAGS-test-math-iscanonical.cc): New variable. * math/test-math-iscanonical.cc: New file. * sysdeps/ieee754/ldbl-96/bits/iscanonical.h (iscanonical): Provide a C++ implementation based on function overloading, rather than using __MATH_TG, which uses C-only builtins. * sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h (iscanonical): Likewise. * sysdeps/powerpc/powerpc64le/Makefile (CFLAGS-test-math-iscanonical.cc): New variable. --- math/Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'math/Makefile') diff --git a/math/Makefile b/math/Makefile index 6c8aa3e413..008eeb2d18 100644 --- a/math/Makefile +++ b/math/Makefile @@ -208,7 +208,8 @@ tests-internal = test-matherr test-matherr-2 tests-static += atest-exp atest-sincos atest-exp2 ifneq (,$(CXX)) -tests += test-math-isinff test-math-iszero test-math-issignaling +tests += test-math-isinff test-math-iszero test-math-issignaling \ + test-math-iscanonical endif ifneq (no,$(PERL)) @@ -356,6 +357,7 @@ CFLAGS-test-signgam-ullong-init-static.c = -std=c99 CFLAGS-test-math-isinff.cc = -std=gnu++11 CFLAGS-test-math-iszero.cc = -std=gnu++11 CFLAGS-test-math-issignaling.cc = -std=gnu++11 +CFLAGS-test-math-iscanonical.cc = -std=gnu++11 CFLAGS-test-iszero-excess-precision.c = -fexcess-precision=standard CFLAGS-test-iseqsig-excess-precision.c = -fexcess-precision=standard -- cgit v1.2.3