Add a special rule for the effect of Array.array

minoki · minoki · commit dcc47300b07b · 2025-09-28T17:12:19.000+09:00
diff --git a/src/cps/syntax.sml b/src/cps/syntax.sml
@@ -266,6 +266,12 @@ struct
       | isDiscardable (PrimOp {primOp = F.ConstructExnOp, ...}) = true
       | isDiscardable (PrimOp {primOp = F.ConstructExnWithPayloadOp, ...}) =
           true
+      | isDiscardable
+          (PrimOp
+             { primOp = F.PrimCall (Primitives.Array_array _)
+             , args = [IntConst (_, n), _]
+             , ...
+             }) = 0 <= n andalso n <= 0xffffffff
       | isDiscardable (PrimOp {primOp = F.PrimCall p, args, ...}) =
           Primitives.isDiscardableWithArgs (p, List.map getPrimEffect args)
       | isDiscardable (PrimOp {primOp = F.JsCallOp, args = e :: _, ...}) =
diff --git a/src/primitives.lua b/src/primitives.lua
@@ -863,7 +863,7 @@ do
       srcname = "Array_array",
       type = { vars = {TV.a}, args = {intA, TV.a}, results = {array(TV.a)} },
       mayraise = true,
-      discardable = false,
+      discardable = false, -- There is a special rule in CSyntax.isDiscardable
     },
     {
       name = "Unsafe.cast",

Original file line number	Diff line number	Diff line change
`@@ -863,7 +863,7 @@ do`
`863`	`863`	`srcname = "Array_array",`
`864`	`864`	`type = { vars = {TV.a}, args = {intA, TV.a}, results = {array(TV.a)} },`
`865`	`865`	`mayraise = true,`
`866`		`- discardable = false,`
	`866`	`+ discardable = false, -- There is a special rule in CSyntax.isDiscardable`
`867`	`867`	`},`
`868`	`868`	`{`
`869`	`869`	`name = "Unsafe.cast",`