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author | Joseph Myers <joseph@codesourcery.com> | 2017-08-22 17:55:42 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2017-08-22 17:55:42 +0000 |
commit | d9bef9c0a41bc3ca4036542cbf2a7d2d0cf60237 (patch) | |
tree | da821dc6e3782dfeed9df3151577b492aaa2afa2 /sysdeps | |
parent | 988f991b5069f09d793c887618e84a196b100416 (diff) | |
download | glibc-d9bef9c0a41bc3ca4036542cbf2a7d2d0cf60237.tar.gz glibc-d9bef9c0a41bc3ca4036542cbf2a7d2d0cf60237.tar.xz glibc-d9bef9c0a41bc3ca4036542cbf2a7d2d0cf60237.zip |
Fix tgmath.h handling of complex integers (bug 21684).
The tgmath.h macros return a real type not a complex type when an argument is of complex integer type (a GNU extension) and there are no arguments of complex floating type. It seems clear that just as real integers are mapped to double for tgmath.h, so complex integers should be mapped to _Complex double. This patch implements such a mapping. The main complication in fixing this bug is that the tgmath.h macros expand their arguments a large number of times, resulting in exponential blowup of the size of the expansion when calls to tgmath.h macros are used in the arguments of such macros; it would be unfortunate for fixing a bug with a fairly obscure extension to make the macros expand their arguments even more times. Thus, this patch optimizes the definitions of the relevant macros. __tgmath_real_type previously expanded its argument 7 times and now expands it 3 times. __tgmath_complex_type, used in place of __tgmath_real_type only for functions that might return either real or complex types, not for complex functions that always return real types or always return complex types, expands its argument 5 times. So the sizes of the macro expansions from nested macro calls are correspondingly reduced (remembering that each tgmath.h macro expands __tgmath_real_type, or sometimes now __tgmath_complex_type, several times). Sometimes the real return type resulted from calling a complex function and converting the result to a real type; sometimes it resulted from calling a real function, because the logic for determining whether arguments were real or complex, based on sizeof, was confused by integer promotions applying to e.g. short int but not _Complex short int. The relevant tests are converted to use a new macro __expr_is_real, which, by calling __builtin_classify_type rather than comparing the results of two calls to sizeof, also reduces the number of times macros expand their arguments. Although there are reductions in the number of times macros expand their arguments, I do not consider this to fix bug 21660, since a proper fix means each macro expanding its arguments only once (via using new compiler features designed for that purpose). Tested for x86_64. [BZ #21684] * math/tgmath.h (__floating_type): Simplify definitions. (__real_integer_type): New macro. (__complex_integer_type): Likewise. (__expr_is_real): Likewise. (__tgmath_real_type_sub): Update comment to describe handling of complex types. (__tgmath_complex_type_sub): New macro. (__tgmath_complex_type): Likewise. [__HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)] (__TGMATH_CF128): Use __expr_is_real. (__TGMATH_UNARY_REAL_IMAG): Use __tgmath_complex_type and __expr_is_real. (__TGMATH_BINARY_REAL_IMAG): Likewise. (__TGMATH_UNARY_REAL_IMAG_RET_REAL): Use __expr_is_real. * math/gen-tgmath-tests.py (Type.create_type): Create complex integer types.
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