[compile] error "use of infinity via a macro is undefined behavior" using the arm toolchain

[tonycurtis]

Describe the bug

error in compilation

for details, see end of this text

Steps to Reproduce

• UCX version used (from github branch XX or release YY) + UCX configure flags (can be checked by ucx_info -v)

master @ 03245a7

Setup and versions

• OS version (e.g Linux distro) + CPU architecture (x86_64/aarch64/ppc64le/...)

Rocky 8.4 + aarch64 (a64fx)

• cat /etc/issue or cat /etc/redhat-release + uname -a

Linux fj-debug2 4.18.0-305.25.1.el8_4.aarch64 #1 SMP Tue Nov 2 21:37:36 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux

Additional information (depending on the issue)

• compiler version

Arm Toolchain for Linux 21.1 clang version 21.1.1 (https://github.com/arm/arm-toolchain.git 8406e267866a1511ab7f7d56ef7361208c0d44ae)

libtool: compile:  armclang -DHAVE_CONFIG_H -I. -I../../../ucx-git/src/ucm -I../.. -DCPU_FLAGS= -I/lustre/projects/ucx-group/src/ucx/build/../ucx-git/src -I/lustre/projects/ucx-group/src/ucx/build -I/lustre/projects/ucx-group/src/ucx/build/src -DUCM_MALLOC_PREFIX=ucm_dl -fno-strict-aliasing -DUSE_LOCKS=1 -DMALLINFO_FIELD_TYPE=int -I/usr/include -O3 -g -Wall -Werror -fmax-type-align=16 -fno-omit-frame-pointer -funwind-tables -Wframe-larger-than=8192 -Wno-missing-field-initializers -Wno-unused-parameter -Wno-unused-label -Wno-long-long -Wno-endif-labels -Wno-sign-compare -Wno-multichar -Wno-deprecated-declarations -Winvalid-pch -Wno-pointer-sign -Werror-implicit-function-declaration -Wno-format-zero-length -Wnested-externs -Wshadow -Werror=declaration-after-statement -Wno-deprecated-declarations -O3 -ffast-math -mcpu=a64fx -MT event/libucm_la-event.lo -MD -MP -MF event/.deps/libucm_la-event.Tpo -c ../../../ucx-git/src/ucm/event/event.c  -fPIC -DPIC -DUCX_SHARED_LIB -o event/.libs/libucm_la-event.o
In file included from ../../../ucx-git/src/ucm/event/event.c:13:
In file included from /lustre/projects/ucx-group/src/ucx/build/../ucx-git/src/ucm/mmap/mmap.h:11:
In file included from /lustre/projects/ucx-group/src/ucx/build/../ucx-git/src/ucm/util/sys.h:13:
/lustre/projects/ucx-group/src/ucx/build/../ucx-git/src/ucs/time/time.h:166:16: error: 
      use of infinity via a macro is undefined behavior due to the currently enabled
      floating-point options [-Werror,-Wnan-infinity-disabled]
  166 |         return INFINITY;
      |                ^
/lustre/projects/ucx-group/src/ucx/build/../ucx-git/src/ucs/time/time.h:166:16: error: 
      use of infinity is undefined behavior due to the currently enabled floating-point
      options [-Werror,-Wnan-infinity-disabled]
  166 |         return INFINITY;
      |                ^~~~~~~~
/usr/include/math.h:91:21: note: expanded from macro 'INFINITY'
   91 | #  define INFINITY (__builtin_inff ())
      |                     ^~~~~~~~~~~~~~~~~
2 errors generated.