-instance Outputable a => Outputable (ProtoBCO a) where
- ppr (ProtoBCO name instrs origin)
- = (text "ProtoBCO" <+> ppr name <> colon)
- $$ nest 6 (vcat (map ppr instrs))
- $$ case origin of
- Left alts -> vcat (map (pprCoreAlt.deAnnAlt) alts)
- Right rhs -> pprCoreExpr (deAnnotate rhs)
+
+-- The stack use, in words, of each bytecode insn. These _must_ be
+-- correct, or overestimates of reality, to be safe.
+bciStackUse :: BCInstr -> Int
+bciStackUse (STKCHECK n) = 0
+bciStackUse (ARGCHECK n) = 0
+bciStackUse (PUSH_L offset) = 1
+bciStackUse (PUSH_LL o1 o2) = 2
+bciStackUse (PUSH_LLL o1 o2 o3) = 3
+bciStackUse (PUSH_G globalish) = 1
+bciStackUse (PUSH_AS nm pk) = 2
+bciStackUse (PUSH_UBX lit nw) = nw
+bciStackUse (PUSH_TAG n) = 1
+bciStackUse (ALLOC sz) = 1
+bciStackUse (UNPACK sz) = sz
+bciStackUse (UPK_TAG n m k) = n + 1{-tag-}
+bciStackUse (LABEL lab) = 0
+bciStackUse (TESTLT_I i lab) = 0
+bciStackUse (TESTEQ_I i lab) = 0
+bciStackUse (TESTLT_F f lab) = 0
+bciStackUse (TESTEQ_F f lab) = 0
+bciStackUse (TESTLT_D d lab) = 0
+bciStackUse (TESTEQ_D d lab) = 0
+bciStackUse (TESTLT_P i lab) = 0
+bciStackUse (TESTEQ_P i lab) = 0
+bciStackUse CASEFAIL = 0
+bciStackUse ENTER = 0
+bciStackUse (RETURN pk) = 0
+
+-- These insns actually reduce stack use, but we need the high-tide level,
+-- so can't use this info. Not that it matters much.
+bciStackUse (SLIDE n d) = 0
+bciStackUse (MKAP offset sz) = 0
+bciStackUse (PACK dcon sz) = 1 -- worst case is PACK 0 words
+