Izaron added a comment. This patch is similar to `__bultin_fmax`: https://reviews.llvm.org/D134369
The constexpr version of ilogb matches the libc realization, this is verified with the same tests: https://github.com/llvm/llvm-project/blob/main/libc/test/src/math/ILogbTest.h test_special_numbers -> ILOGB_TEST_SPECIAL_NUMBERS test_powers_of_two -> ILOGB_TEST_POWERS_OF_TWO test_some_integers -> ILOGB_TEST_SOME_INTEGERS https://eel.is/c++draft/library.c#3 says that a floating-point exception other than `FE_INEXACT` causes it to not be a constant expression. I check it with small `ilog` function refactoring and the new function `isConstantOpStatus`. The online documentation (https://en.cppreference.com/w/cpp/numeric/math/ilogb) says: 1. If the correct result is greater than INT_MAX or smaller than INT_MIN, FE_INVALID is raised. 2. If arg is ±0, ±∞, or NaN, FE_INVALID is raised. 3. In all other cases, the result is exact (FE_INEXACT is never raised) and the current rounding mode is ignored The first point seemingly never occur, because llvm's `ilogb` return type is `int`. The second point is handled as expected (`APFloatTest.cpp` checks it) Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D136568/new/ https://reviews.llvm.org/D136568 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
