975af797f1
Most x87 instruction implementations 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 the x87 status word. There is special-case handling of division to raise the divide-by-zero exception, but that handling is itself buggy: it raises the exception in inappropriate cases (inf / 0 and nan / 0, which should not raise any exceptions, and 0 / 0, which should raise "invalid" instead). Fix this by converting the floating-point exceptions raised during an operation by the softfloat machinery into exceptions in the x87 status word (passing through the existing fpu_set_exception function for handling related to trapping exceptions). There are special cases where some functions convert to integer internally but exceptions from that conversion are not always correct exceptions for the instruction to raise. There might be scope for some simplification if the softfloat exception state either could always be assumed to be in sync with the state in the status word, or could always be ignored at the start of each instruction and just set to 0 then; I haven't looked into that in detail, and it might run into interactions with the various ways the emulation does not yet handle trapping exceptions properly. I think the approach taken here, of saving the softfloat state, setting exceptions there to 0 and then merging the old exceptions back in after carrying out the operation, is conservatively safe. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Message-Id: <alpine.DEB.2.21.2005152120280.3469@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-fbstp.c | ||
| test-i386-fisttp.c | ||
| test-i386-fldcst.c | ||
| test-i386-fp-exceptions.c | ||
| test-i386-fprem.c | ||
| test-i386-fscale.c | ||
| test-i386-fxam.c | ||
| test-i386-fxtract.c | ||
| test-i386-muldiv.h | ||
| test-i386-pseudo-denormal.c | ||
| test-i386-shift.h | ||
| test-i386-snan-convert.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 ----------