Regression in codegen-llvm test riscv-abi/call-llvm-intrinsics.rs on riscv64 since 1.94-beta

[DeepeshWR]

The test tests/codegen-llvm/riscv-abi/call-llvm-intrinsics.rs started failing on riscv64 from rustc 1.94.0-beta.

It was passing with rustc 1.93.0.

The failure occurs because FileCheck no longer finds the expected store instruction in the generated LLVM IR.

1.93 (passing) :

store float 4.000000e+00, ptr %3, align 4
%5 = call float @llvm.sqrt.f32(float %4)

1.94-beta (failing) :

%_2 = call float @llvm.sqrt.f32(float 4.000000e+00)

In 1.94.0-beta, the constant 4.0 is passed directly to llvm.sqrt.f32, and the intermediate store (and corresponding load) are no longer emitted, causing the CHECK pattern to fail.

I have attached the following files for reference :

call-llvm-intrinsics-1.93.0.ll

call-llvm-intrinsics-1.94.0.ll

Backtrace.txt

[tgross35]

As a note, that test (and probably others in the same directory) should probably be converted to an //@ add-minicore test so they get run even when the host isn't rv64

[tgross35]

If you are interested in fixing this, it should be pretty easy to update to the new version. With the minicore change it will need //@ needs-llvm-components: riscv and may need //@ min-llvm-version: ... to pass CI with the older versions.

[DeepeshWR]

@tgross35 Thanks for the suggestion! I tried adding //@ add-minicore and //@ needs-llvm-components: riscv, but still fails with same failure.

NOTE: This testcase was passing till rust-1.93.0

[tgross35]

@tgross35 Thanks for the suggestion! I tried adding //@ add-minicore and //@ needs-llvm-components: riscv, but still fails with same failure.

NOTE: This testcase was passing till rust-1.93.0

This is the only relevant bit for the fix:

If you are interested in fixing this, it should be pretty easy to update to the new version.

Meaning you'll need to change the CHECK statements to match. The rest is just how to get the test running & passing in our CI