improvmenets to delay slot modeling (lua metaprogram)

code/duffle/gen/duffle.macs.h

@@ -2,7 +2,7 @@
 #pragma once
 #endif
 // Auto-generated by ps1_meta.lua — DO NOT EDIT
-// Source: C:\projects\pikuma\ps1\code\duffle\lottes_tape.h
+// Source: C:\projects\Pikuma\ps1\code\duffle\lottes_tape.h
 // Component atoms (MipsAtomComp_(ac_*)) -> macro variants (mac_*)
 
 #ifndef WORD_COUNT

code/duffle/gen/duffle.offsets.h

@@ -1,5 +1,5 @@
 // Auto-generated by ps1_meta.lua (passes/offsets.lua) — DO NOT EDIT
-// Source: C:\projects\pikuma\ps1\code\duffle\lottes_tape.h
+// Source: C:\projects\Pikuma\ps1\code\duffle\lottes_tape.h
 #pragma once
 
 #pragma region lottes_tape

code/hello_joypad/gen/hello_joypad.macs.h

@@ -2,7 +2,7 @@
 #pragma once
 #endif
 // Auto-generated by ps1_meta.lua — DO NOT EDIT
-// Source: C:\projects\pikuma\ps1\code\hello_joypad\hello_joypad.tape.c
+// Source: C:\projects\Pikuma\ps1\code\hello_joypad\hello_joypad.tape.c
 // Component atoms (MipsAtomComp_(ac_*)) -> macro variants (mac_*)
 
 #ifndef WORD_COUNT

code/hello_joypad/gen/hello_joypad.offsets.h

@@ -1,5 +1,5 @@
 // Auto-generated by ps1_meta.lua (passes/offsets.lua) — DO NOT EDIT
-// Source: C:\projects\pikuma\ps1\code\hello_joypad\hello_joypad.tape.c
+// Source: C:\projects\Pikuma\ps1\code\hello_joypad\hello_joypad.tape.c
 #pragma once
 
 #pragma region hello_joypad.tape

scripts/duffle.lua

@@ -1700,22 +1700,45 @@ M.HARDWARE_RELATIONS = {
 	},
 	-- Memory -> COP2 data register (LWC2).
 	-- The memory-side timing is not measured by the vendored GTE latch experiment, so this relation has no numeric retirement threshold.
-	-- The forward walker emits one info edge at the first command-input consumer and then clears the pending relation.
+	-- The LWC2 destination has TWO retirement regimes (per PSX-SPX):
+	--   * GTE-command consumer (`gte_cmdw_*`): the GTE pipeline LATCHES the LWC2 result, so a `gte_cmdw_*`
+	--     in the very next slot uses the latched value. Gap = 0 is allowed.
+	--     (Per `docs/psx-spx/docs/gtepipelinetimings.md:271-274`.)
+	--   * Any other consumer: standard MIPS load delay applies. Gap = 1 required.
+	--     (Per `docs/psx-spx/docs/cpuspecifications.md:407-419`.)
+	-- Two separate relations so the walker can dispatch by consumer type and emit
+	-- different severities (the GTE-command path is `info` because the latch is intentional;
+	-- the non-GTE-consumer path is `error` because the missing nop is a real bug).
 	{
-		id             = "lwc2_unknown_visibility",
+		id             = "lwc2_to_gte_command",
-		semantic       = "LWC2",
+		semantic       = "LWC2_to_GTE",
 		token          = "gte_lw",
 		direction      = "memory_to_cop2_data",
 		reads          = { domain = "memory",    arg = 2 },
 		writes         = { domain = "cop2.data", arg = 1 },
-		visibility     = { kind = "unknown_consumer", required = nil },
+		required       = 0,  -- GTE-command consumer: gap = 0 OK (latched).
 		evidence       = {
-			confidence = "unknown",
+			confidence = "measured",
 			source     = "gtepipelinetimings.md:271-274",
 		},
 		violation_kind = "info",
 		clear_on_consumer = true,
 	},
+	{
+		id             = "lwc2_to_other_consumer",
+		semantic       = "LWC2_to_other",
+		token          = "gte_lw",
+		direction      = "memory_to_cop2_data",
+		reads          = { domain = "memory",    arg = 2 },
+		writes         = { domain = "cop2.data", arg = 1 },
+		required       = 1,  -- Non-GTE-consumer: standard MIPS load delay.
+		evidence       = {
+			confidence = "inferred",
+			source     = "cpuspecifications.md:407-419",
+		},
+		violation_kind = "error",
+		clear_on_consumer = true,
+	},
 	-- COP2 data register -> memory (SWC2). A read of C2 state, not a CPU-to-COP2 write.
 	-- The policy row stays in for direction/provenance; staging it as a later command-input producer is suppressed.
 	{

scripts/passes/static_analysis.lua

@@ -401,6 +401,18 @@ end
 -- therefore counts ONLY words strictly between the producer and the consumer.
 -- ─────────────────────────────────────────────────────────────────────────
 
+-- True iff `consumer_event` is a GTE command (gte_cmdw_* or one of the human-readable aliases
+-- mapped in `duffle.GTE_COMMAND_ALIASES`). Used by the LWC2 retirement-regime dispatch in the
+-- forward walker: a GTE-command consumer can read the LWC2 result in the very next slot (the GTE
+-- pipeline latches the LWC2 data); any other consumer must observe the standard MIPS load delay
+-- (gap >= 1).
+local function is_gte_command(consumer_event)
+	local tok = consumer_event.encoder or consumer_event.ident or ""
+	if tok:sub(1, 9) == "gte_cmdw_" then return true end
+	local aliases = duffle.GTE_COMMAND_ALIASES or {}
+	return aliases[tok] ~= nil
+end
+
 -- True iff `consumer_word` falls inside the COP2 command's input set OR inside the producer's `fanout_to` set (for IRGB writes).
 -- Used by the consumer-match step of the forward walker.
 local function is_cop2_consumer_of(consumer_event, destination, producer_rel)
@@ -817,9 +829,17 @@ local function analyze_hardware_relations(atom)
 			local relation = prod.relation
 			local semantic = relation.semantic
 			local is_match = false
-			if semantic == "MTC2" or semantic == "CTC2" or semantic == "LWC2" then
+			if semantic == "MTC2" or semantic == "CTC2" or semantic == "LWC2_to_GTE" or semantic == "LWC2_to_other" then
 				-- Consumer is a GTE command whose input set contains the producer's COP2 destination (or a fan-out target).
-				is_match = is_cop2_consumer_of(ev, prod.destination, relation)
+				-- LWC2_to_GTE  — GTE-command consumer: gap = 0 OK (the pipeline latches the LWC2 result).
+				-- LWC2_to_other — non-GTE consumer: standard load delay applies.
+				if relation.id == "lwc2_to_gte_command" then
+					is_match = is_gte_command(ev) and is_cop2_consumer_of(ev, prod.destination, relation)
+				elseif relation.id == "lwc2_to_other_consumer" then
+					is_match = (not is_gte_command(ev)) and is_cop2_consumer_of(ev, prod.destination, relation)
+				else
+					is_match = is_cop2_consumer_of(ev, prod.destination, relation)
+				end
 			elseif semantic == "MFC2" or semantic == "CFC2" or semantic == "MFC0" then
 				-- Consumer is any encoder that reads the producer's GPR destination as an operand.
 				is_match = is_gpr_consumer_of(ev, prod.destination)
@@ -1163,6 +1183,8 @@ end
 local function check_hazard_nop_use(atom, _pipe_ctx, findings)
 	local forward = atom.paths and atom.paths.forward_state
 	local events  = atom.paths.word_events or {}
+	-- GPR effects table used to resolve load destinations when classifying load-delay-slot nops.
+	local gpr_effects = duffle.INSTRUCTION_GPR_EFFECTS or {}
 	if not events or #events == 0 then return end
 	-- Runtime-helper atoms / components (e.g. tape_exit, ac_yield) carry `debug_skip = true` from the bare
 	-- `atom_dbg_skip` marker; their structural nops are part of the fixed handshake and not author choices.
@@ -1180,9 +1202,10 @@ local function check_hazard_nop_use(atom, _pipe_ctx, findings)
 
 		-- Classify the nop BEFORE its event is applied to the pending state.
 		if ev_ident == "nop" and prev_ev ~= nil then
-			-- Skip BD-slot nops: they are exclusively owned by control_transfer_delay_slot_use.
+			-- Skip BD-slot nops that are exclusively owned by control_transfer_delay_slot_use
+			-- (the nop after a branch/jump — covered by that check separately).
 			-- Every BD-slot nop is structural; this check never reports on it.
-			-- (The earlier `if not suppressed then is_bd_slot = true end` form inverted the suppression — the `mac_yield()` handshake's `jump_reg(R_AtomJmp)` was incorrectly flagged.)
+			-- (The earlier `if not suppressed then is_bd_slot = true end` form inverted the suppression - the `mac_yield()` handshake's `jump_reg(R_AtomJmp)` was incorrectly flagged.)
 			local prev_ident   = prev_ev.encoder or ""
 			local bd_policies  = duffle.CONTROL_TRANSFER_DELAY_SLOT_POLICIES or {}
 			local is_bd_slot   = bd_policies[prev_ident] ~= nil
@@ -1243,20 +1266,52 @@ local function check_hazard_nop_use(atom, _pipe_ctx, findings)
 				else
 					-- Track the slot_kind so the BD-separation case can assert the mac_yield handshake is still suppressed.
 					local slot_kind = "plain"
-					findings[#findings + 1] = {
+					-- MIPS load-delay slot: a `load_*` wrote a register in the previous slot, and the result
-						check              = "hazard_nop_use",
+					-- is unavailable for 1 cycle. This `nop` is structurally required; classifying it as
-						kind               = "info",
+					-- `modeled-required` is the correct signal (removing it would make the following
-						atom               = atom.name,
+					-- instruction read the OLD value of the loaded register, a load-use hazard). The
-						line               = ev_line,
+					-- `load_delay_violations` check (Concern 3) catches the actual read-side error; here
-						source             = ev.def_path or ev.source or "",
+					-- we suppress the `modeled-redundant` misclassification.
-						nop_classification = "modeled-redundant",
+					-- The set of load instructions mirrors the LOAD_INSTRUCTION_IDENTS in `check_load_delay_slots`.
-						nop_word_index     = ev_word,
+					local load_idents    = { load_word = true, load_half = true, load_half_u = true,
-						retired_relation   = nil,
+					                         load_byte = true, load_byte_u = true, gte_lw = true, gte_lwc2 = true }
-						slot_kind          = slot_kind,
+					local is_load_delay = load_idents[prev_ident] == true
-						msg = string.format("%s at line %d: nop at word %d is modeled-redundant (no pending modeled relation)"
+					if is_load_delay then
-							, atom.name, ev_line, ev_word
+						-- Determine the destination register from the load's `writes` field.
-						),
+						local prev_writes   = gpr_effects[prev_ident] and gpr_effects[prev_ident].writes or {}
-					}
+						local prev_args     = prev_ev.args or {}
+						local load_dest     = prev_writes[1] and prev_args[prev_writes[1]] or "<load-destination>"
+						findings[#findings + 1] = {
+							check                = "hazard_nop_use",
+							kind                 = "info",
+							atom                 = atom.name,
+							line                 = ev_line,
+							source               = ev.def_path or ev.source or "",
+							nop_classification   = "modeled-required",
+							nop_word_index       = ev_word,
+							retired_relation     = "load_delay_slot",
+							producer_destination = load_dest,
+							consumer_token       = "<would-be-consumer>",
+							msg = string.format("%s at line %d: nop at word %d is modeled-required (load-delay slot for %s)"
+								, atom.name, ev_line, ev_word, load_dest
+							),
+						}
+					else
+						findings[#findings + 1] = {
+							check              = "hazard_nop_use",
+							kind               = "info",
+							atom               = atom.name,
+							line               = ev_line,
+							source             = ev.def_path or ev.source or "",
+							nop_classification = "modeled-redundant",
+							nop_word_index     = ev_word,
+							retired_relation   = nil,
+							slot_kind          = slot_kind,
+							msg = string.format("%s at line %d: nop at word %d is modeled-redundant (no pending modeled relation)"
+								, atom.name, ev_line, ev_word
+							),
+						}
+					end
 				end
 			end
 		end