Struct regalloc::StackmapRequestInfo

pub struct StackmapRequestInfo {
    pub reftype_class: RegClass,
    pub reftyped_vregs: Vec<VirtualReg>,
    pub safepoint_insns: Vec<InstIx>,
}

A structure with which callers can request stackmap information.

Fields

reftype_class: RegClass

The register class that holds reftypes. This may only be RegClass::I32 or RegClass::I64, and it must equal the word size of the target architecture.

reftyped_vregs: Vec<VirtualReg>

The virtual regs that hold reftyped values. These must be provided in ascending order of register index and be duplicate-free. They must have class reftype_class.

safepoint_insns: Vec<InstIx>

The indices of instructions for which the allocator will construct stackmaps. These must be provided in ascending order and be duplicate-free. The specified instructions may not be coalescable move instructions (as the allocator may remove those) and they may not modify any register carrying a reftyped value (they may “def” or “use” them, though). The reason is that, at a safepoint, the client’s garbage collector may change the values of all live references, so it would be meaningless for a safepoint instruction also to attempt to do that – we’d end up with two competing new values.