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Review fixes;

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This commit is contained in:
Benjamin Bouvier
2020-07-24 17:04:34 +02:00
parent ad4a2f919f
commit 35d9ab19b7
8 changed files with 191 additions and 145 deletions
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57
cranelift/codegen/src/machinst/buffer.rs
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@@ -258,8 +258,20 @@ impl MachLabel {
}
}
/// A stackmap extent, when creating a stackmap.
pub enum StackmapExtent {
/// The stack map starts at this instruction, and ends after the number of upcoming bytes
/// (note: this is a code offset diff).
UpcomingBytes(CodeOffset),
/// The stack map started at the given offset and ends at the current one. This helps
/// architectures where the instruction size has not a fixed length.
StartedAtOffset(CodeOffset),
}
impl<I: VCodeInst> MachBuffer<I> {
/// Create a new section, known to start at `start_offset` and with a size limited to `length_limit`.
/// Create a new section, known to start at `start_offset` and with a size limited to
/// `length_limit`.
pub fn new() -> MachBuffer<I> {
MachBuffer {
data: SmallVec::new(),
@@ -1159,32 +1171,27 @@ impl<I: VCodeInst> MachBuffer<I> {
}
}
/// Add stackmap metadata for this program point: a set of stack offsets
/// (from SP upward) that contain live references.
/// Add stackmap metadata for this program point: a set of stack offsets (from SP upward) that
/// contain live references.
///
/// The `offset_to_fp` value is the offset from the nominal SP (at which the
/// `stack_offsets` are based) and the FP value. By subtracting
/// `offset_to_fp` from each `stack_offsets` element, one can obtain
/// live-reference offsets from FP instead.
pub fn add_stackmap(&mut self, insn_len: CodeOffset, stackmap: Stackmap) {
let offset = self.cur_offset();
/// The `offset_to_fp` value is the offset from the nominal SP (at which the `stack_offsets`
/// are based) and the FP value. By subtracting `offset_to_fp` from each `stack_offsets`
/// element, one can obtain live-reference offsets from FP instead.
pub fn add_stackmap(&mut self, extent: StackmapExtent, stackmap: Stackmap) {
let (start, end) = match extent {
StackmapExtent::UpcomingBytes(insn_len) => {
let start_offset = self.cur_offset();
(start_offset, start_offset + insn_len)
}
StackmapExtent::StartedAtOffset(start_offset) => {
let end_offset = self.cur_offset();
debug_assert!(end_offset >= start_offset);
(start_offset, end_offset)
}
};
self.stackmaps.push(MachStackMap {
offset,
offset_end: offset + insn_len,
stackmap,
});
}
/// Add stackmap metadata for this program point: a set of stack offsets
/// (from SP upward) that contain live references.
///
/// Method variant of `add_stackmap` that is easier to manipulate for non-fixed-sizes
/// instructions.
pub fn add_stackmap_ending_at(&mut self, start_offset: CodeOffset, stackmap: Stackmap) {
let cur_offset = self.cur_offset();
self.stackmaps.push(MachStackMap {
offset: start_offset,
offset_end: cur_offset,
offset: start,
offset_end: end,
stackmap,
});
}