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Merged
alexcrichton merged 1 commit into from
Jul 2, 2026
+9 −6
Merged

Tag the stack switching control context temp slot with an alias region #13800

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8 changes: 5 additions & 3 deletions crates/cranelift/src/func_environ/stack_switching/instructions.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1921,13 +1921,15 @@ pub(crate) fn translate_switch<'a>(
let tmp_control_context = builder.ins().stack_addr(env.pointer_type(), slot, 0);

// The `*_last_ancestor_cc` control contexts live on continuation
// stacks, but the temporary lives in a current-frame stack slot, so
// only the former get the continuation-stack-memory region.
// stacks, but the temporary lives in a current-frame stack slot, so the
// former get the continuation-stack-memory region while the latter gets
// its own stack-slot region.
let region = env
.alias_regions
.continuation_stack_memory_region(builder.func);
let cc_flags = MemFlagsData::trusted().with_alias_region(Some(region));
let tmp_flags = MemFlagsData::trusted();
let tmp_region = env.alias_regions.stack_slot_region(builder.func, slot);
let tmp_flags = MemFlagsData::trusted().with_alias_region(Some(tmp_region));
let mut offset: i32 = 0;
while offset < i32::from(cctx_size) {
// switchee_last_ancestor_cc -> tmp control context
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7 changes: 4 additions & 3 deletions tests/disas/stack-switching/symmetric-switch.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,7 @@
;; region3 = 134217816 "VMStoreContext+0x58"
;; region4 = 2281701376 "ContinuationStackMemory+0x0"
;; region5 = 134217800 "VMStoreContext+0x48"
;; region6 = 3087007744 "Stack(ss0)"
;; gv0 = vmctx
;; gv1 = load.i64 notrap aligned readonly can_move region0 gv0+8
;; gv2 = load.i64 notrap aligned region1 gv1+24
Expand Down Expand Up @@ -204,15 +205,15 @@
;; @003e v118 = iadd v116, v117 ; v117 = -24
;; @003e v119 = stack_addr.i64 ss0
;; @003e v120 = load.i64 notrap aligned region4 v118
;; @003e store notrap aligned v120, v119
;; @003e store notrap aligned region6 v120, v119
;; @003e v121 = load.i64 notrap aligned region4 v113
;; @003e store notrap aligned region4 v121, v118
;; @003e v122 = load.i64 notrap aligned region4 v118+8
;; @003e store notrap aligned v122, v119+8
;; @003e store notrap aligned region6 v122, v119+8
;; @003e v123 = load.i64 notrap aligned region4 v113+8
;; @003e store notrap aligned region4 v123, v118+8
;; @003e v124 = load.i64 notrap aligned region4 v118+16
;; @003e store notrap aligned v124, v119+16
;; @003e store notrap aligned region6 v124, v119+16
;; @003e v125 = load.i64 notrap aligned region4 v113+16
;; @003e store notrap aligned region4 v125, v118+16
;; @003e v126 = iconst.i64 3
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