If the host doesn't support the instructions required for implementing
an instruction then don't even add them to the opcodedispatcher.
This means that we will never try emitting instructions that the host
doesn't support (For these instructions anyway) and successfully passes
the guest SIGILL for these particular instructions.
Fixes#1631
Was incorrectly setting the FCW to 037h when it was supposed to be
037Fh.
Fixes a bug in a visual novel where its CPUID state wouldn't initialize
if this was set incorrectly.
I misread the implementation details of this instruction when
implementing.
The pseudocode says `ST(0) = ST(0) ∗ 2^rndint(ST(1))` so I understood
the instruction to use the current rounding mode of the host to extract
the integer portion of `ST(1)`.
The actual implementation is in the details of the statement `the
integer portion of the floating- point value in ST(1).`
This behaves like round towards zero/truncate, additional hardware
testing and documentation reading confirms this.
Fixes#1584
The run_thunkgen* helpers now parse generated source code and return its AST
representation, so HasASTMatching helper calls don't each need to redundantly
compile it themselves. This also ensures the generator output actually compiles
in tests where we didn't explicitly check that before.
This also allows printing the full AST of the generator output on test
failures. This must be enabled manually by changing a variable in the ostream
output operator for SourceWithAST.
Just noticed this while casually reading the x86 architecture manuals.
The move segment registers instructions ignore the REX.R prefix on the
segment register.
Previously this was expected to create an invalid register selection.
A little bit silly but sure, support it.
The instruction decode tables for crc32 introduced some dumb.
`F2h` and `F2h && 66h` prefixes both work for crc32.
This is a failure on Intel's part for sticking crc32 in to the vector
table.
MOVBE without any prefixes also does the same garbage where prefix `66h`
acts as an operand prefix size ONLY.
Some of these behaviours have changed now, particularly around signal
handling.
Some things still fail now of course. But most everything is now
documented as to why it is failing or disabled.
Fixes#955
