This is a set of four patches to target/i386 which use the core fpu functionality we just landed for Arm FEAT_AFP to correct the emulation of some corner cases of x86 floating point: * when we are flushing denormal outputs to zero, this should be done after rounding, not before * the MXCSR.DE and FPUS.DE bits indicate when a denormal input was not flushed and was used in an fp operation; we previously weren't implementing these semantics
All four patches have been reviewed by RTH. Testing is a bit light (make check-tcg and make check-functional), because AFAIK there is no freely available comprehensive FP testsuite for x86, and risu doesn't support x86 currently so I can't do the same kind of random-instruction-testing I could for Arm. thanks -- PMM Peter Maydell (4): target/i386: Detect flush-to-zero after rounding target/i386: Use correct type for get_float_exception_flags() values target/i386: Wire up MXCSR.DE and FPUS.DE correctly tests/tcg/x86_64/fma: add test for exact-denormal output target/i386/ops_sse.h | 16 +++--- target/i386/tcg/fpu_helper.c | 101 +++++++++++++++++------------------ tests/tcg/x86_64/fma.c | 17 ++++-- 3 files changed, 68 insertions(+), 66 deletions(-) -- 2.43.0
