This reverts commit 5d9b720189a64eec7f35f844320d0b30ca3997f3.
Obscure bugs resulting from this commit due to assumptions regarding zero-extension of higher bits.
* We failed to invalidate entries if there are no patches required for a location descriptor.
* Bug in A64 hashing code (rbx instead of rbp).
* Bug in A32 and A64 lookup code (inconsistent choice of key: PC vs IR::LocationDescriptor).
* Test case added.
`MConst` is refactored into `XmmConst` to clearly communicate the
addressable space of the newly allocated 16-byte memory constant.
`GetVectorOf` is elevated into a globally available `XmmBConst` function
that "broadcasts" bits of the input-value into n-bit elements that span
the width of the Xmm-constant.
`emit_x64_floating_point` will utilize the same 16-byte
broadcasted-constants to encourage more cache-hits within the
constant-pool between vector and non-vector code.
`vfpclassp* k, xmm, i8` has better latency(4->3) and allocates better
execution ports(01->5) that are out of the way of ALU-ports than
`vcmpunordp* xmm, xmm, xmm`(`vcmpp* xmm, xmm, xmm, i8`) and removes the
pipeline dependency on `xmm0` in favor AVX512 `k`-mask registers.
`vblendmp* xmm, k, xmm, mem` is about the same throughput and latency as
`blendvp* xmm. mem` but has the benefit of embedded broadcasts to reduce
memory bandwidth(32/64-bit read rather than 128-bit) and lends itself to
a future size optimization feature of `constant_pool`.
Both single and double precision floating point numbers as well as the
packed and unpacked version of this instruction will be able to use the
same memory constant. This takes advantage of the fact that `VFIXUPIMM*`
doesn't just copy from the source, but it will convert to `0.0` if it
turns out that it is a denormal and the `MXCSR.DAZ` flag is set.
```
tsrc[31:0]←((src1[30:23] = 0) AND (MXCSR.DAZ =1)) ? 0.0 : src1[31:0]
...
CASE(token_response[3:0]) {
...
0001: dest[31:0]←tsrc[31:0]; ; pass through src1 normal input value, denormal as zero
...
```
There is an important subtlety that should be documented here. All the
operands of `FpFixup` that read from the `Src` register actually do a
`DAZ` operation if `MXCSR.DAZ` is set.
Intended to be used for library users wishing implement accurate memory watchpoints.
* A32: optionally make memory instructions the end of basic blocks
* A64: optionally make memory instructions the end of basic blocks
* Make memory halt checking a user configurable
* oops
