6cf7155052
* Generalize unsigned `(x << k) >> k` optimization Split the existing rule into three parts: - A dual of the rule for `(x >> k) << k` that is only valid for unsigned shifts. - Known-bits analysis for `(band (uextend x) k)`. - A new rule for converting `sextend` to `uextend` if the sign-extended bits are masked out anyway. The first two together cover the existing rule. * Generalize signed `(x << k) >> k` optimization * Review comments * Generalize sign-extending shifts further The shifts can be eliminated even if the shift amount isn't exactly equal to the difference in bit-widths between the narrow and wide types. * Add filetests
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.