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The SSE instruction implementations all fail to raise the expected IEEE floating-point exceptions because they do nothing to convert the exception state from the softfloat machinery into the exception flags in MXCSR. Fix this by adding such conversions. Unlike for x87, emulated SSE floating-point operations might be optimized using hardware floating point on the host, and so a different approach is taken that is compatible with such optimizations. The required invariant is that all exceptions set in env->sse_status (other than "denormal operand", for which the SSE semantics are different from those in the softfloat code) are ones that are set in the MXCSR; the emulated MXCSR is updated lazily when code reads MXCSR, while when code sets MXCSR, the exceptions in env->sse_status are set accordingly. A few instructions do not raise all the exceptions that would be raised by the softfloat code, and those instructions are made to save and restore the softfloat exception state accordingly. Nothing is done about "denormal operand"; setting that (only for the case when input denormals are *not* flushed to zero, the opposite of the logic in the softfloat code for such an exception) will require custom code for relevant instructions, or else architecture-specific conditionals in the softfloat code for when to set such an exception together with custom code for various SSE conversion and rounding instructions that do not set that exception. Nothing is done about trapping exceptions (for which there is minimal and largely broken support in QEMU's emulation in the x87 case and no support at all in the SSE case). Signed-off-by: Joseph Myers <joseph@codesourcery.com> Message-Id: <alpine.DEB.2.21.2006252358000.3832@digraph.polyomino.org.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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| .. | ||
| system | ||
| hello-i386.c | ||
| Makefile.softmmu-target | ||
| Makefile.target | ||
| README | ||
| test-i386-code16.S | ||
| test-i386-f2xm1.c | ||
| test-i386-fbstp.c | ||
| test-i386-fisttp.c | ||
| test-i386-fldcst.c | ||
| test-i386-fp-exceptions.c | ||
| test-i386-fpatan.c | ||
| test-i386-fprem.c | ||
| test-i386-fscale.c | ||
| test-i386-fxam.c | ||
| test-i386-fxtract.c | ||
| test-i386-fyl2x.c | ||
| test-i386-fyl2xp1.c | ||
| test-i386-muldiv.h | ||
| test-i386-pcmpistri.c | ||
| test-i386-pseudo-denormal.c | ||
| test-i386-shift.h | ||
| test-i386-snan-convert.c | ||
| test-i386-sse-exceptions.c | ||
| test-i386-ssse3.c | ||
| test-i386-vm86.S | ||
| test-i386.c | ||
| test-i386.h | ||
These are i386 specific guest programs test-i386 --------- This program executes most of the 16 bit and 32 bit x86 instructions and generates a text output, for comparison with the output obtained with a real CPU or another emulator. The Linux system call modify_ldt() is used to create x86 selectors to test some 16 bit addressing and 32 bit with segmentation cases. The Linux system call vm86() is used to test vm86 emulation. Various exceptions are raised to test most of the x86 user space exception reporting. linux-test ---------- This program tests various Linux system calls. It is used to verify that the system call parameters are correctly converted between target and host CPUs. test-i386-fprem --------------- test-mmap --------- sha1 ---- hello-i386 ----------