automatic import of glibcopeneuler22.03_LTS_SP4openeuler22.03_LTS_SP3openeuler20.03

1 files changed, 176 insertions, 0 deletions

diff --git a/stdlib-strfrom-Add-copysign-to-fix-NAN-issue-on-risc.patch b/stdlib-strfrom-Add-copysign-to-fix-NAN-issue-on-risc.patch
new file mode 100644
index 0000000..baaeb5e
--- /dev/null
+++ b/stdlib-strfrom-Add-copysign-to-fix-NAN-issue-on-risc.patch
@@ -0,0 +1,176 @@
+From 0cc0033ef19bd3378445c2b851e53d7255cb1b1e Mon Sep 17 00:00:00 2001
+From: Letu Ren <fantasquex@gmail.com>
+Date: Fri, 21 Oct 2022 22:54:50 +0800
+Subject: [PATCH] stdlib/strfrom: Add copysign to fix NAN issue on riscv (BZ
+ #29501)
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+According to the specification of ISO/IEC TS 18661-1:2014,
+
+The strfromd, strfromf, and strfroml functions are equivalent to
+snprintf(s, n, format, fp) (7.21.6.5), except the format string contains only
+the character %, an optional precision that does not contain an asterisk *, and
+one of the conversion specifiers a, A, e, E, f, F, g, or G, which applies to
+the type (double, float, or long double) indicated by the function suffix
+(rather than  by a length modifier). Use of these functions with any other 20
+format string results in undefined behavior.
+
+strfromf will convert the arguement with type float to double first.
+
+According to the latest version of IEEE754 which is published in 2019,
+
+Conversion of a quiet NaN from a narrower format to a wider format in the same
+radix, and then back to the same narrower format, should not change the quiet
+NaN payload in any way except to make it canonical.
+
+When either an input or result is a NaN, this standard does not interpret the
+sign of a NaN. However, operations on bit strings—copy, negate, abs,
+copySign—specify the sign bit of a NaN result, sometimes based upon the sign
+bit of a NaN operand. The logical predicates totalOrder and isSignMinus are
+also affected by the sign bit of a NaN operand. For all other operations, this
+standard does not specify the sign bit of a NaN result, even when there is only
+one input NaN, or when the NaN is produced from an invalid operation.
+
+converting NAN or -NAN with type float to double doesn't need to keep
+the signbit. As a result, this test case isn't mandatory.
+
+The problem is that according to RISC-V ISA manual in chapter 11.3 of
+riscv-isa-20191213,
+
+Except when otherwise stated, if the result of a floating-point operation is
+NaN, it is the canonical NaN. The canonical NaN has a positive sign and all
+significand bits clear except the MSB, a.k.a. the quiet bit. For
+single-precision floating-point, this corresponds to the pattern 0x7fc00000.
+
+which means that conversion -NAN from float to double won't keep the signbit.
+
+Since glibc ought to be consistent here between types and architectures, this
+patch adds copysign to fix this problem if the string is NAN. This patch
+adds two different functions under sysdeps directory to work around the
+issue.
+
+This patch has been tested on x86_64 and riscv64.
+
+Resolves: BZ #29501
+
+v2: Change from macros to different inline functions.
+v3: Add unlikely check to isnan.
+v4: Fix wrong commit message header.
+v5: Fix style: add space before parentheses.
+v6: Add copyright.
+Signed-off-by: Letu Ren <fantasquex@gmail.com>
+Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
+---
+ stdlib/strfrom-skeleton.c                     |  3 +-
+ .../generic/fix-float-double-convert-nan.h    | 31 ++++++++++++++++
+ .../riscv/rvd/fix-float-double-convert-nan.h  | 37 +++++++++++++++++++
+ 3 files changed, 70 insertions(+), 1 deletion(-)
+ create mode 100644 sysdeps/generic/fix-float-double-convert-nan.h
+ create mode 100644 sysdeps/riscv/rvd/fix-float-double-convert-nan.h
+
+diff --git a/stdlib/strfrom-skeleton.c b/stdlib/strfrom-skeleton.c
+index 1fba04bf6a..36e9adcad5 100644
+--- a/stdlib/strfrom-skeleton.c
++++ b/stdlib/strfrom-skeleton.c
+@@ -27,6 +27,7 @@
+ #include <printf.h>
+ #include <string.h>
+ #include <locale/localeinfo.h>
++#include <fix-float-double-convert-nan.h>
+ 
+ #define UCHAR_T char
+ #define L_(Str) Str
+@@ -61,7 +62,7 @@ STRFROM (char *dest, size_t size, const char *format, FLOAT f)
+      because __printf_fp and __printf_fphex only accept double and long double
+      as the floating-point argument.  */
+   if (__builtin_types_compatible_p (FLOAT, float))
+-    fpnum.flt = f;
++    fpnum.flt = keep_sign_conversion (f);
+   else
+     fpnum.value = f;
+ 
+diff --git a/sysdeps/generic/fix-float-double-convert-nan.h b/sysdeps/generic/fix-float-double-convert-nan.h
+new file mode 100644
+index 0000000000..66692262fc
+--- /dev/null
++++ b/sysdeps/generic/fix-float-double-convert-nan.h
+@@ -0,0 +1,31 @@
++/* Fix for conversion of float NAN to double.  Generic version.
++   Copyright (C) 2022 Free Software Foundation, Inc.
++   This file is part of the GNU C Library.
++
++   The GNU C Library is free software; you can redistribute it and/or
++   modify it under the terms of the GNU Lesser General Public
++   License as published by the Free Software Foundation; either
++   version 2.1 of the License, or (at your option) any later version.
++
++   The GNU C Library is distributed in the hope that it will be useful,
++   but WITHOUT ANY WARRANTY; without even the implied warranty of
++   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++   Lesser General Public License for more details.
++
++   You should have received a copy of the GNU Lesser General Public
++   License along with the GNU C Library.  If not, see
++   <https://www.gnu.org/licenses/>.  */
++
++#ifndef FIX_FLOAT_DOUBLE_CONVERT_NAN_H
++#define FIX_FLOAT_DOUBLE_CONVERT_NAN_H
++
++/* This function aims to work around conversions of float -NAN
++   to double returning NAN instead of the correct -NAN in some
++   architectures.  */
++static inline double __attribute__ ((always_inline))
++keep_sign_conversion (float flt)
++{
++  return flt;
++}
++
++#endif
+diff --git a/sysdeps/riscv/rvd/fix-float-double-convert-nan.h b/sysdeps/riscv/rvd/fix-float-double-convert-nan.h
+new file mode 100644
+index 0000000000..cab003f3c1
+--- /dev/null
++++ b/sysdeps/riscv/rvd/fix-float-double-convert-nan.h
+@@ -0,0 +1,37 @@
++/* Fix for conversion of float NAN to double.  RISC-V version..
++   Copyright (C) 2022 Free Software Foundation, Inc.
++   This file is part of the GNU C Library.
++
++   The GNU C Library is free software; you can redistribute it and/or
++   modify it under the terms of the GNU Lesser General Public
++   License as published by the Free Software Foundation; either
++   version 2.1 of the License, or (at your option) any later version.
++
++   The GNU C Library is distributed in the hope that it will be useful,
++   but WITHOUT ANY WARRANTY; without even the implied warranty of
++   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
++   Lesser General Public License for more details.
++
++   You should have received a copy of the GNU Lesser General Public
++   License along with the GNU C Library.  If not, see
++   <https://www.gnu.org/licenses/>.  */
++
++#ifndef FIX_FLOAT_DOUBLE_CONVERT_NAN_H
++#define FIX_FLOAT_DOUBLE_CONVERT_NAN_H
++
++#include <math.h>
++
++/* RISC-V rvd instructions do not preserve the signbit of NAN
++   when converting from float to double.  */
++static inline double
++keep_sign_conversion (float flt)
++{
++  if (__glibc_unlikely (isnan (flt)))
++  {
++    float x = copysignf (1.f, flt);
++    return copysign ((double) flt, (double) x);
++  }
++  return flt;
++}
++
++#endif
+-- 
+2.39.2
+