GCC enables it by default, clang in the other hand sets -fno-trapping-math.
This is required to fix some math and stdlib tests that explicit raises
floating point exceptions:
math/test-double-canonicalize.out
testing double (without inline functions)
Failure: canonicalize (max_value): Exception "Overflow" set
Failure: canonicalize (max_value): Exception "Inexact" set
Failure: canonicalize (-max_value): Exception "Overflow" set
Failure: canonicalize (-max_value): Exception "Inexact" set
Failure: canonicalize_downward (max_value): Exception "Overflow" set
Failure: canonicalize_downward (max_value): Exception "Inexact" set
Failure: canonicalize_downward (-max_value): Exception "Overflow" set
Failure: canonicalize_downward (-max_value): Exception "Inexact" set
Failure: canonicalize_towardzero (max_value): Exception "Overflow" set
Failure: canonicalize_towardzero (max_value): Exception "Inexact" set
Failure: canonicalize_towardzero (-max_value): Exception "Overflow" set
Failure: canonicalize_towardzero (-max_value): Exception "Inexact" set
Failure: canonicalize_upward (max_value): Exception "Overflow" set
Failure: canonicalize_upward (max_value): Exception "Inexact" set
Failure: canonicalize_upward (-max_value): Exception "Overflow" set
Failure: canonicalize_upward (-max_value): Exception "Inexact" set
test-float-catanh.out
testing float (without inline functions)
Failure: Real part of: catanh (-0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (-0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh (-0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (-0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh (-0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (-0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh (0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh (0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh (0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (-0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (-0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (-0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (-0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (-0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (-0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_downward (0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (-0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (-0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (-0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (-0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (-0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (-0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_towardzero (0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (-0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (-0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (-0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (-0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (-0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (-0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (0x1.000002p+0 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (0x1.000002p+0 - 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (0x1.000002p+0 + 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (0x1.000002p+0 + 0x8p-152 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (0xf.fffffp-4 - 0x4p-128 i): Exception "Underflow" set
Failure: Real part of: catanh_upward (0xf.fffffp-4 + 0x4p-128 i): Exception "Underflow" set
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
# disable any optimization that assume default rounding mode.
+math-flags = -frounding-math
+# We have to assume that glibc functions might generate user-visible traps.
++math-flags += -ftrapping-math
+
# Logically only "libnldbl", "nonlib" and "testsuite" should be using
# -fno-math-errno. However due to GCC bug #88576, only "libm" and
# "libmvec" can use -fno-math-errno.