This patch:
* removes the "default" opt level, on the basis that it has no definition and
is referred to nowhere in the compiler.
* renames the "fastest" level to "none". The resulting set of transformations
is unchanged.
* renames the "best" level to "speed_and_size". The resulting set of
transformations is unchanged.
* adds a new level, "speed". This is the same as "speed_and_size" except that
it omits transformations aimed only at reducing code size. Currently it
omits only the insn shrinking pass.
This commit is based on the assumption that floats are already stored in XMM registers in x86. When extracting a lane, cranelift was moving the float to a regular register and back to an XMM register; this change avoids this by shuffling the float value to the lowest bits of the XMM register. It also assumes that the upper bits can be left as is (instead of zeroing them out).
raw_bitcast matches the intent of this legalization more clearly (to simply change the CLIF type without changing any bits) and the additional null encodings added are necessary for later instructions
* [codegen] add new recipe "rout"
Add a new recipe "rout" intended to be used by arithematic operations
that output flags, currently being used for `iadd_cout` and `isub_bout`.
Fixes: https://github.com/CraneStation/cranelift/issues/1009
The type of the borrow operands for the borrow variants of the isub
instruction (isub_bin, isub_bout, isub_borrow) was bool for compatibility
reasons for isa/riscv. Since support for these instructions on RISC
architectures has been temporarily suspended, we can safely change the
type to iflags.
Previously, the borrow variants of isub (isub_bin, isub_bout and
isub_borrow) were being legalized for isa/riscv since RISC architectures
lack a flags register.
This forced us to return and accept booleans for these operations, which
proved to be problematic and inconvenient, especially for x86.
This commit removes support for said statements and all dependent
statements for isa/riscv so that we can work on a better legalization
strategy in the future.
* [codegen] add encodings for iadd carry variants
Add encodings for iadd carry variants (iadd_cout, iadd_cin, iadd_carry)
for x86_32, enabling the legalization for iadd.i64 to work.
* [codegen] remove support for iadd carry variants on riscv
Previously, the carry variants of iadd (iadd_cin, iadd_cout and
iadd_carry) were being legalized for isa/riscv since RISC architectures
lack a flags register.
This forced us to return and accept booleans for these operations, which
proved to be problematic and inconvenient, especially for x86.
This commit removes support for said statements and all dependent
statements for isa/riscv so that we can work on a better legalization
strategy in the future.
* [codegen] change operand type from bool to iflag for iadd carry variants
The type of the carry operands for the carry variants of the iadd
instruction (iadd_cin, iadd_cout, iadd_carry) was bool for compatibility
reasons for isa/riscv. Since support for these instructions on RISC
architectures has been temporarily suspended, we can safely change the
type to iflags.
Also, as a ridealong fix, removes R32 encodings for x86_64 in `enc_r32_r64`,
since the type `rXX` by definition only exists for targets with word size `XX`
bits.
