tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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math-emu: Add support for reporting exact invalid exception

Some architectures (like powerpc) provide status information on the exact
type of invalid exception. This is pretty straight forward as we already
report invalid exceptions via FP_SET_EXCEPTION.

We add new flags (FP_EX_INVALID_*) the architecture code can define if it
wants the exact invalid exception reported.

We had to split out the INF/INF and 0/0 cases for divide to allow reporting
the two invalid forms properly.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: David S. Miller <davem@davemloft.net>

Kumar Gala 48d6c643 40d3057a

+27 -4
+8 -4
include/math-emu/op-common.h
··· 73 73 X##_c = FP_CLS_NAN; \ 74 74 /* Check for signaling NaN */ \ 75 75 if (!(_FP_FRAC_HIGH_RAW_##fs(X) & _FP_QNANBIT_##fs)) \ 76 - FP_SET_EXCEPTION(FP_EX_INVALID); \ 76 + FP_SET_EXCEPTION(FP_EX_INVALID | FP_EX_INVALID_SNAN); \ 77 77 } \ 78 78 break; \ 79 79 } \ ··· 324 324 _FP_FRAC_SET_##wc(R, _FP_NANFRAC_##fs); \ 325 325 R##_s = _FP_NANSIGN_##fs; \ 326 326 R##_c = FP_CLS_NAN; \ 327 - FP_SET_EXCEPTION(FP_EX_INVALID); \ 327 + FP_SET_EXCEPTION(FP_EX_INVALID | FP_EX_INVALID_ISI); \ 328 328 break; \ 329 329 } \ 330 330 /* FALLTHRU */ \ ··· 431 431 R##_s = _FP_NANSIGN_##fs; \ 432 432 R##_c = FP_CLS_NAN; \ 433 433 _FP_FRAC_SET_##wc(R, _FP_NANFRAC_##fs); \ 434 - FP_SET_EXCEPTION(FP_EX_INVALID); \ 434 + FP_SET_EXCEPTION(FP_EX_INVALID | FP_EX_INVALID_IMZ);\ 435 435 break; \ 436 436 \ 437 437 default: \ ··· 490 490 break; \ 491 491 \ 492 492 case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_INF): \ 493 + R##_s = _FP_NANSIGN_##fs; \ 494 + R##_c = FP_CLS_NAN; \ 495 + _FP_FRAC_SET_##wc(R, _FP_NANFRAC_##fs); \ 496 + FP_SET_EXCEPTION(FP_EX_INVALID | FP_EX_INVALID_IDI);\ 493 497 case _FP_CLS_COMBINE(FP_CLS_ZERO,FP_CLS_ZERO): \ 494 498 R##_s = _FP_NANSIGN_##fs; \ 495 499 R##_c = FP_CLS_NAN; \ 496 500 _FP_FRAC_SET_##wc(R, _FP_NANFRAC_##fs); \ 497 - FP_SET_EXCEPTION(FP_EX_INVALID); \ 501 + FP_SET_EXCEPTION(FP_EX_INVALID | FP_EX_INVALID_ZDZ);\ 498 502 break; \ 499 503 \ 500 504 default: \
+19
include/math-emu/soft-fp.h
··· 51 51 #ifndef FP_EX_INVALID 52 52 #define FP_EX_INVALID 0 53 53 #endif 54 + #ifndef FP_EX_INVALID_SNAN 55 + #define FP_EX_INVALID_SNAN 0 56 + #endif 57 + /* inf - inf */ 58 + #ifndef FP_EX_INVALID_ISI 59 + #define FP_EX_INVALID_ISI 0 60 + #endif 61 + /* inf / inf */ 62 + #ifndef FP_EX_INVALID_IDI 63 + #define FP_EX_INVALID_IDI 0 64 + #endif 65 + /* 0 / 0 */ 66 + #ifndef FP_EX_INVALID_ZDZ 67 + #define FP_EX_INVALID_ZDZ 0 68 + #endif 69 + /* inf * 0 */ 70 + #ifndef FP_EX_INVALID_IMZ 71 + #define FP_EX_INVALID_IMZ 0 72 + #endif 54 73 #ifndef FP_EX_OVERFLOW 55 74 #define FP_EX_OVERFLOW 0 56 75 #endif