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Rename "local variables" to "explicit stack slots".

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The term "local variables" predated the SSA builder in the front-end
crate, which also provides a way to implement source-language local
variables. The name "explicit stack slot" makes it clear what this
construct is.
This commit is contained in:
Dan Gohman
2018-02-28 13:58:46 -08:00
parent c93f29ad1e
commit 5dc449ec9e
8 changed files with 42 additions and 34 deletions
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17
lib/cretonne/src/stack_layout.rs
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@@ -7,8 +7,8 @@ use std::cmp::{min, max};
/// Compute the stack frame layout.
///
/// Determine the total size of this stack frame and assign offsets to all `Spill` and `Local`
/// stack slots.
/// Determine the total size of this stack frame and assign offsets to all `Spill` and
/// `Explicit` stack slots.
///
/// The total frame size will be a multiple of `alignment` which must be a power of two.
///
@@ -25,7 +25,7 @@ pub fn layout_stack(frame: &mut StackSlots, alignment: StackSize) -> Result<Stac
// stack layout from high to low addresses will be:
//
// 1. incoming arguments.
// 2. spills + locals.
// 2. spills + explicits.
// 3. outgoing arguments.
//
// The incoming arguments can have both positive and negative offsets. A negative offset
@@ -57,15 +57,15 @@ pub fn layout_stack(frame: &mut StackSlots, alignment: StackSize) -> Result<Stac
outgoing_max = max(outgoing_max, offset);
}
StackSlotKind::SpillSlot |
StackSlotKind::Local |
StackSlotKind::ExplicitSlot |
StackSlotKind::EmergencySlot => {
// Determine the smallest alignment of any local or spill slot.
// Determine the smallest alignment of any explicit or spill slot.
min_align = slot.alignment(min_align);
}
}
}
// Lay out spill slots and locals below the incoming arguments.
// Lay out spill slots and explicit slots below the incoming arguments.
// The offset is negative, growing downwards.
// Start with the smallest alignments for better packing.
let mut offset = incoming_min;
@@ -74,9 +74,10 @@ pub fn layout_stack(frame: &mut StackSlots, alignment: StackSize) -> Result<Stac
for ss in frame.keys() {
let slot = frame[ss].clone();
// Pick out locals and spill slots with exact alignment `min_align`.
// Pick out explicit and spill slots with exact alignment `min_align`.
match slot.kind {
StackSlotKind::SpillSlot | StackSlotKind::Local => {
StackSlotKind::SpillSlot |
StackSlotKind::ExplicitSlot => {
if slot.alignment(alignment) != min_align {
continue;
}