mirror of
git://sourceware.org/git/glibc.git
synced 2025-02-11 12:50:58 +08:00
1272748886
The ldbl-128ibm implementations of lrintl and lroundl are missing "invalid" exceptions for certain overflow cases when compiled with GCC 8. The cause of this is after-the-fact integer overflow checks that fail when the compiler optimizes on the basis of integer overflow being undefined; GCC 8 must be able to detect new cases of undefinedness here. Failure: lrint (-0x80000001p0): Exception "Invalid operation" not set Failure: lrint_downward (-0x80000001p0): Exception "Invalid operation" not set Failure: lrint_towardzero (-0x80000001p0): Exception "Invalid operation" not set Failure: lrint_upward (-0x80000001p0): Exception "Invalid operation" not set Failure: lround (-0x80000001p0): Exception "Invalid operation" not set Failure: lround_downward (-0x80000001p0): Exception "Invalid operation" not set Failure: lround_towardzero (-0x80000001p0): Exception "Invalid operation" not set Failure: lround_upward (-0x80000001p0): Exception "Invalid operation" not set (Tested that these failures occur before the patch for powerpc soft-float, but the issue applies in principle for hard-float as well, whether or not the particular optimizations in fact occur there at present.) This patch fixes the bug by ensuring the additions / subtractions in question cast arguments to unsigned long int, or use 1UL as a constant argument, so that the arithmetic occurs in an unsigned type with the result then converted back to a signed type. Tested for powerpc (soft-float). [BZ #22690] * sysdeps/ieee754/ldbl-128ibm/s_lrintl.c (__lrintl): Use unsigned long int for arguments of possibly overflowing addition or subtraction. * sysdeps/ieee754/ldbl-128ibm/s_lroundl.c (__lroundl): Likewise. |
||
|---|---|---|
| .. | ||
| dbl-64 | ||
| float128 | ||
| flt-32 | ||
| ldbl-64-128 | ||
| ldbl-96 | ||
| ldbl-128 | ||
| ldbl-128ibm | ||
| ldbl-opt | ||
| soft-fp | ||
| ieee754.h | ||
| k_standard.c | ||
| k_standardf.c | ||
| k_standardl.c | ||
| Makefile | ||
| s_lib_version.c | ||
| s_matherr.c | ||
| s_signgam.c | ||