4ca9e82bd1
Adds Bswap to the Cranelift IR. Implements the Bswap instruction in the x64 and aarch64 codegen backends. Cranelift users can now: ``` builder.ins().bswap(value) ``` to get a native byteswap instruction. * x64: implements the 32- and 64-bit bswap instruction, following the pattern set by similar unary instrutions (Neg and Not) - it only operates on a dst register, but is parameterized with both a src and dst which are expected to be the same register. As x64 bswap instruction is only for 32- or 64-bit registers, the 16-bit swap is implemented as a rotate left by 8. Updated x64 RexFlags type to support emitting for single-operand instructions like bswap * aarch64: Bswap gets emitted as aarch64 rev16, rev32, or rev64 instruction as appropriate. * s390x: Bswap was already supported in backend, just had to add a bit of plumbing * For completeness, added bswap to the interpreter as well. * added filetests and runtests for each ISA * added bswap to fuzzgen, thanks to afonso360 for the code there * 128-bit swaps are not yet implemented, that can be done later
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.