This is the floating point equivalent of trapif: Trap when a given
condition is in the floating-point flags.
Define Intel encodings comparable to the trapif encodings.
These Intel-specific instructions represent the semantics of the minss /
maxss Intel instructions which behave more like a C ternary operator
than the WebAssembly fmin and fmax instructions.
They will be used as building blocks for implementing the WebAssembly
semantics.
This is used to represent the non-trapping semantics of the cvttss2si and
cvttsd2si instructions (and their vectorized counterparts).
The overflow behavior of this instruction is specific to the Intel ISAs.
There is no float-to-i64 instruction on the 32-bit Intel ISA.
Not all floating point condition codes are directly supported by the
ucimiss/ucomisd instructions. Some inequalities need to be reversed and
eq+ne require two separate tests.
To begin with, these are catch-all encodings with a SIB byte and a
32-bit displacement, so they can access any stack slot via both the
stack pointer and the frame pointer.
In the future, we will add encodings for 8-bit displacements as well as
EBP-relative references without a SIB byte.
The following instructions have simple encodings:
- bitcast.f32.i32
- bitcast.i32.f32
- bitcast.f64.i64
- bitcast.i64.f64
- fpromote.f64.f32
- fdemote.f32.f64
Also add helper functions enc_flt() and enc_i32_i64 to
intel.encodings.py for generating the common set of encodings for an
instruction: I32, I64 w/REX, I64 w/o REX.
The encoding tables are keyed by the controlling type variable only. We
need to distinguish different encodings for instructions with multiple
type variables.
Add a TypePredicate instruction predicate which can check the type of an
instruction value operand. Combine type checks into the instruction
predicate for instructions with more than one type variable.
Add Intel encodings for fcvt_from_sint.f32.i64 which can now be
distinguished from fcvt_from_sint.f32.i32.
These map to single Intel instructions.
The i64 to float conversions are not tested yet. The encoding tables
can't yet differentiate instructions on a secondary type variable alone.
