07518dfd36
* Remove the Cranelift `vselect` instruction This instruction is documented as selecting lanes based on the "truthy" value of the condition lane, but the current status of the implementation of this instruction is: * x64 - uses the high bit for `f32x4` and `f64x2` and otherwise uses the high bit of each byte doing a byte-wise lane select rather than whatever the controlling type is. * AArch64 - this is the same as `bitselect` which is a bit-wise selection rather than a lane-wise selection. * s390x - this is the same as AArch64, a bit-wise selection rather than lane-wise. * interpreter - the interpreter implements the documented semantics of selecting based on "truthy" values. Coupled with the status of the implementation is the fact that this instruction is not used by WebAssembly SIMD today either. The only use of this instruction in Cranelift is the nan-canonicalization pass. By moving nan-canonicalization to `bitselect`, since that has the desired semantics, there's no longer any need for `vselect`. Given this situation this commit subsqeuently removes `vselect` and all usage of it throughout Cranelift. Closes #5917 * Review comments * Bring back vselect opts as bitselect opts * Clean up vselect usage in the interpreter * Move bitcast in nan canonicalization * Add a comment about float optimization
filetests
Filetests is a crate that contains multiple test suites for testing
various parts of cranelift. Each folder under cranelift/filetests/filetests is a different
test suite that tests different parts.
Adding a runtest
One of the available testsuites is the "runtest" testsuite. Its goal is to compile some piece of clif code, run it and ensure that what comes out is what we expect.
To build a run test you can add the following to a file:
test interpret
test run
target x86_64
target aarch64
target s390x
function %band_f32(f32, f32) -> f32 {
block0(v0: f32, v1: f32):
v2 = band v0, v1
return v2
}
; run: %band_f32(0x0.5, 0x1.0) == 0x1.5
Since this is a run test for band we can put it in: runtests/band.clif.
Once we have the file in the test suite we can run it by invoking: cargo run -- test filetests/filetests/runtests/band.clif from the cranelift directory.
The first lines tell clif-util what kind of tests we want to run on this file.
test interpret invokes the interpreter and checks if the conditions in the ; run comments pass. test run does the same, but compiles the file and runs it as a native binary.
For more information about testing see testing.md.