Stream: git-cranelift

Topic: cranelift / Issue #922 How do I negate a bool?

GitHub (Feb 28 2020 at 23:26):

alexcrichton transferred Issue #922:

I'm trying to compile this simple C program:

int main() {
    return !1;
}

I'll spare you the parsing, what my program does after implicit casts is:

• create a literal using let val = builder.ins().iconst(types::I32, 1);, where builder is a FunctionBuilder
• cast 1 to B1 using let val = builder.ins().icmp_imm(condcodes::IntCC::NotEqual, val, 0);
• negate the B1 using let val = builder.ins().bnot(val);
• extend the B1 to I32 using builder.ins().bint(types::I32, val)

This gives me a verifier error: VerifierError { location: inst2, message: "v2 is a real GPR value defined by a ghost instruction" }.

What, if anything, am I doing wrong? I see that rustc_codegen_cranelift extends the bool to an I32, do I need to do that?

Last updated: Dec 06 2025 at 05:03 UTC