managed frames

docs/managed_stack_frames.md

@@ -0,0 +1,231 @@
+# Managed Stack Frames Implementation Plan
+
+This document outlines the requirements and invariants for implementing fully managed stack frames in QuickJS, eliminating recursion through the C stack for JS->JS calls.
+
+## Overview
+
+The goal is to maintain interpreter state entirely on managed stacks (value stack + frame stack) rather than relying on C stack frames. This enables:
+- **Call IC fast path**: Direct dispatch to C functions without js_call_c_function overhead
+- **Proper stack traces**: Error().stack works correctly even through optimized paths
+- **Tail call optimization**: Possible without C stack growth
+- **Debugging/profiling**: Full interpreter state always inspectable
+
+## Current State
+
+- Property IC: Implemented with per-function polymorphic IC (up to 4 shapes per site)
+- Call IC: Infrastructure exists but disabled (`CALL_IC_ENABLED 0`) because it bypasses stack frame setup required for Error().stack
+
+## Golden Invariant
+
+**At any time, the entire live interpreter state must be reconstructible from:**
+```
+(ctx->value_stack, value_top) + (ctx->frame_stack, frame_top)
+```
+
+No critical state may live only in C locals.
+
+## Implementation Requirements
+
+### 1. Offset Semantics (use `size_t` / `uint32_t`)
+
+Replace pointer-based addressing with offset-based addressing:
+
+```c
+typedef struct JSStackFrame {
+    uint32_t sp_offset;        // Offset into ctx->value_stack
+    uint32_t var_offset;       // Start of local variables
+    uint32_t arg_offset;       // Start of arguments
+    // ... continuation info below
+} JSStackFrame;
+```
+
+**Rationale**: Offsets survive stack reallocation, pointers don't.
+
+### 2. Consistent `sp_offset` Semantics
+
+Define clearly and consistently:
+- `sp_offset` = current stack pointer offset from `ctx->value_stack`
+- On function entry: `sp_offset` points to first free slot after arguments
+- On function exit: `sp_offset` restored to caller's expected position
+
+### 3. Continuation Info (Caller State Restoration)
+
+Each frame must store enough to restore caller state on return:
+
+```c
+typedef struct JSStackFrame {
+    // ... other fields
+
+    // Continuation info
+    const uint8_t *caller_pc;      // Return address in caller's bytecode
+    uint32_t caller_sp_offset;     // Caller's stack pointer
+    JSFunctionBytecode *caller_b;  // Caller's bytecode (for IC cache)
+
+    // Current function info
+    JSFunctionBytecode *b;         // Current function's bytecode
+    JSValue *var_buf;              // Can be offset-based
+    JSValue *arg_buf;              // Can be offset-based
+    JSValue this_val;
+} JSStackFrame;
+```
+
+### 4. Exception Handler Stack Depth Restoration
+
+Exception handlers must record the `sp_offset` at handler entry so `throw` can restore the correct stack depth:
+
+```c
+typedef struct JSExceptionHandler {
+    uint32_t sp_offset;        // Stack depth to restore on throw
+    const uint8_t *catch_pc;   // Where to jump on exception
+    // ...
+} JSExceptionHandler;
+```
+
+On `throw`:
+1. Unwind frame stack to find appropriate handler
+2. Restore `sp_offset` to handler's recorded value
+3. Push exception value
+4. Jump to `catch_pc`
+
+### 5. Aliased `argv` Handling
+
+When `arguments` object exists, `argv` may be aliased. The frame must track this:
+
+```c
+typedef struct JSStackFrame {
+    // ...
+    uint16_t flags;
+    #define JS_FRAME_ALIASED_ARGV  (1 << 0)
+    #define JS_FRAME_STRICT        (1 << 1)
+    // ...
+    JSObject *arguments_obj;   // Non-NULL if arguments object created
+} JSStackFrame;
+```
+
+When `JS_FRAME_ALIASED_ARGV` is set, writes to `arguments[i]` must update the corresponding local variable.
+
+### 6. Stack Trace Accuracy (`sf->cur_pc`)
+
+**Critical**: `sf->cur_pc` must be updated before any operation that could:
+- Throw an exception
+- Call into another function
+- Trigger GC
+
+Currently the interpreter does:
+```c
+sf->cur_pc = pc;  // Before potentially-throwing ops
+```
+
+With managed frames, ensure this is consistently done or use a different mechanism (e.g., store pc in frame on every call).
+
+### 7. GC Integration
+
+The GC must be able to mark all live values on the managed stacks:
+
+```c
+void js_gc_mark_value_stack(JSRuntime *rt) {
+    for (JSContext *ctx = rt->context_list; ctx; ctx = ctx->link) {
+        JSValue *p = ctx->value_stack;
+        JSValue *end = ctx->value_stack + ctx->value_top;
+        while (p < end) {
+            JS_MarkValue(rt, *p);
+            p++;
+        }
+    }
+}
+
+void js_gc_mark_frame_stack(JSRuntime *rt) {
+    for (JSContext *ctx = rt->context_list; ctx; ctx = ctx->link) {
+        JSStackFrame *sf = ctx->frame_stack;
+        JSStackFrame *end = ctx->frame_stack + ctx->frame_top;
+        while (sf < end) {
+            JS_MarkValue(rt, sf->this_val);
+            // Mark any other JSValue fields in frame
+            sf++;
+        }
+    }
+}
+```
+
+### 8. Main Interpreter Loop Changes
+
+Transform from recursive to iterative:
+
+```c
+// Current (recursive):
+JSValue JS_CallInternal(...) {
+    // ...
+    CASE(OP_call):
+        // Recursive call to JS_CallInternal
+        ret = JS_CallInternal(ctx, func, ...);
+    // ...
+}
+
+// Target (iterative):
+JSValue JS_CallInternal(...) {
+    // ...
+    CASE(OP_call):
+        // Push new frame, update pc to callee entry
+        push_frame(ctx, ...);
+        pc = new_func->byte_code_buf;
+        BREAK;  // Continue in same loop iteration
+
+    CASE(OP_return):
+        // Pop frame, restore caller state
+        ret_val = sp[-1];
+        pop_frame(ctx, &pc, &sp, &b);
+        sp[0] = ret_val;
+        BREAK;  // Continue executing caller
+    // ...
+}
+```
+
+## Call IC Integration (After Managed Frames)
+
+Once managed frames are complete, Call IC becomes safe:
+
+```c
+CASE(OP_call_method):
+    // ... resolve method ...
+
+    if (JS_VALUE_GET_TAG(method) == JS_TAG_OBJECT) {
+        JSObject *p = JS_VALUE_GET_OBJ(method);
+
+        // Check Call IC
+        CallICEntry *entry = call_ic_lookup(cache, pc_offset, p->shape);
+        if (entry && entry->cfunc) {
+            // Direct C call - safe because frame is on managed stack
+            push_minimal_frame(ctx, pc, sp_offset);
+            ret = entry->cfunc(ctx, this_val, argc, argv);
+            pop_minimal_frame(ctx);
+            // Handle return...
+        }
+    }
+
+    // Slow path: full call
+```
+
+## Testing Strategy
+
+1. **Stack trace tests**: Verify Error().stack works through all call patterns
+2. **Exception tests**: Verify throw/catch restores correct stack depth
+3. **GC stress tests**: Verify all values are properly marked during GC
+4. **Benchmark**: Compare performance before/after
+
+## Migration Steps
+
+1. [ ] Add offset fields to JSStackFrame alongside existing pointers
+2. [ ] Create push_frame/pop_frame helper functions
+3. [ ] Convert OP_call to use push_frame instead of recursion (JS->JS calls)
+4. [ ] Convert OP_return to use pop_frame
+5. [ ] Update exception handling to use offset-based stack restoration
+6. [ ] Update GC to walk managed stacks
+7. [ ] Remove/deprecate recursive JS_CallInternal calls for JS functions
+8. [ ] Enable Call IC for C functions
+9. [ ] Benchmark and optimize
+
+## References
+
+- Current IC implementation: `source/quickjs.c` lines 12567-12722 (ICCache, prop_ic_*)
+- Current stack frame: `source/quickjs.c` JSStackFrame definition
+- OP_call_method: `source/quickjs.c` lines 13654-13718

internal/engine.cm

@@ -140,12 +140,19 @@ globalThis.isa = function(value, master) {
 var ENETSERVICE = 0.1
 var REPLYTIMEOUT = 60 // seconds before replies are ignored
 
+var nullguard = false
 function caller_data(depth = 0)
 {
   var file = "nofile"
   var line = 0
   
   var caller = new Error().stack.split("\n")[1+depth]
+  if (!nullguard && is_null(caller)) {
+    os.print(`caller_data now getting null`)
+    os.print("\n")
+    nullguard = true
+  }
+
   if (caller) {
     var md = caller.match(/\((.*)\:/)
     var m = md ? md[1] : "SCRIPT"
@@ -809,19 +816,28 @@ stone(globalThis)
 
 var rads = use_core("math/radians")
 log.console(rads)
+log.console("now, should be nofile:0")
 
 $_.clock(_ => {
+  log.console("in clock")
   // Get capabilities for the main program
   var file_info = shop.file_info ? shop.file_info(locator.path) : null
   var inject = shop.script_inject_for ? shop.script_inject_for(file_info) : []
 
+  log.console("injection")
+
   // Build values array for injection
   var vals = []
+  log.console(`number to inject is ${inject.length}`)
+  log.console('when the log.console statements are in the loop, with backticks, it runs but with errors on the injectables especially substring not seeming to work; without them, it totally fails')
   for (var i = 0; i < inject.length; i++) {
     var key = inject[i]
+    log.console(`injecting ${i}, which is ${key}`) // when this line is present, works; when not present, does not work
+
     if (key && key[0] == '$') key = key.substring(1)
     if (key == 'fd') vals.push(fd)
     else vals.push($_[key])
+    log.console(`split at 1 was ${key}`)
   }
 
   // Create use function bound to the program's package

meson.build

@@ -74,7 +74,7 @@ foreach file: scripts
 endforeach
 
 srceng = 'source'
-includes = [srceng, 'internal', 'debug', 'net', 'archive', 'math']
+includes = [srceng, 'internal', 'debug', 'net', 'archive']
 
 foreach file : src
   full_path = join_paths(srceng, file)

source/quickjs.c

@@ -642,30 +642,54 @@ typedef enum {
   IC_STATE_MEGA,
 } ic_state;
 
-/* Property lookup IC (monomorphic case) */
+/* Max entries for polymorphic IC */
+#define IC_POLY_SIZE 4
+
+/* Property lookup IC entry (for mono and poly) */
 typedef struct {
   JSShape *shape;    /* expected shape */
   uint32_t offset;   /* property offset in prop array */
+} PropICEntry;
+
+/* Property lookup IC with polymorphic support */
+typedef struct {
+  PropICEntry entries[IC_POLY_SIZE];
+  uint8_t count;     /* number of valid entries (0-4) */
 } GetPropIC;
 
 typedef struct {
-  JSShape *shape;
-  uint32_t offset;
+  PropICEntry entries[IC_POLY_SIZE];
+  uint8_t count;
 } SetPropIC;
 
-/* Call IC (monomorphic case) */
+/* Call IC entry - stores enough to dispatch directly to C functions */
 typedef struct {
-  JSObject *func_obj;       /* expected function object */
-  JSFunctionBytecode *b;    /* direct pointer to bytecode */
-  uint8_t is_bytecode_func; /* 1 if bytecode function, 0 if native */
-  uint8_t expected_argc;    /* expected argument count */
+  JSObject *func_obj;         /* expected function object (for identity check) */
+  union {
+    struct {
+      JSFunctionBytecode *bytecode;
+    } js;
+    struct {
+      JSCFunctionType c_function;  /* direct C function pointer */
+      JSContext *realm;            /* function's realm */
+      uint8_t cproto;              /* calling convention */
+      int16_t magic;               /* magic value for *_magic variants */
+    } native;
+  } u;
+  uint8_t is_native;            /* 1 if C function, 0 if bytecode */
+} CallICEntry;
+
+/* Call IC with polymorphic support */
+typedef struct {
+  CallICEntry entries[IC_POLY_SIZE];
+  uint8_t count;               /* number of valid entries */
 } CallIC;
 
 /* Unified IC slot with tagged union */
 typedef struct ICSlot {
   uint8_t kind;      /* ic_kind */
   uint8_t state;     /* ic_state */
-  uint16_t aux;      /* auxiliary flags/data */
+  uint16_t aux;      /* auxiliary flags/data (e.g., atom for prop IC) */
   union {
     GetPropIC get_prop;
     SetPropIC set_prop;
@@ -12540,6 +12564,231 @@ static void close_lexical_var(JSContext *ctx, JSStackFrame *sf, int var_idx)
     }
 }
 
+/* ============================================================================
+ * Per-function Inline Cache (IC) System
+ *
+ * We use a per-function hash table keyed by pc_offset to avoid TLS collisions.
+ * The hash table is allocated lazily on first IC miss. This approach:
+ * - Eliminates the 256-entry TLS cache collision problem
+ * - Supports polymorphic caching (up to IC_POLY_SIZE shapes per site)
+ * - Keeps IC state with the function for better locality
+ *
+ * The IC cache uses a unified slot structure that can hold property or call ICs.
+ * ============================================================================ */
+
+#define IC_HASH_BITS 10
+#define IC_HASH_SIZE (1 << IC_HASH_BITS)
+
+/* Property IC slot - supports polymorphic shapes */
+typedef struct PropICSlot {
+    uint32_t pc_offset;         /* bytecode offset of access site */
+    struct {
+        JSShape *shape;         /* expected shape */
+        uint32_t prop_idx;      /* property index in shape */
+    } entries[IC_POLY_SIZE];
+    uint8_t count;              /* number of valid entries (0 = uninit, 1-4 = poly) */
+} PropICSlot;
+
+/* Call IC slot - for future use with managed stack frames */
+typedef struct CallICSlot {
+    uint32_t pc_offset;         /* bytecode offset of call site */
+    JSObject *func_obj;         /* expected function object (for identity check) */
+    union {
+        struct {
+            JSFunctionBytecode *bytecode;
+        } js;
+        struct {
+            JSCFunctionType c_function;  /* direct C function pointer */
+            JSContext *realm;            /* function's realm */
+            uint8_t cproto;              /* calling convention */
+            int16_t magic;               /* magic value for *_magic variants */
+        } native;
+    } u;
+    uint8_t is_native;          /* 1 if C function, 0 if bytecode */
+    uint8_t valid;              /* 1 if entry is valid */
+} CallICSlot;
+
+/* Unified IC cache - one per function, lazily allocated */
+typedef struct ICCache {
+    PropICSlot prop_slots[IC_HASH_SIZE];
+    /* CallICSlot call_slots[IC_HASH_SIZE]; - for future call IC */
+} ICCache;
+
+static force_inline uint32_t ic_hash(uint32_t pc_offset)
+{
+    /* Knuth multiplicative hash - pc offsets are well-distributed */
+    return (pc_offset * 2654435761u) >> (32 - IC_HASH_BITS);
+}
+
+/* Ensure IC cache is allocated for a function */
+static force_inline ICCache *ic_ensure_cache(JSRuntime *rt, JSFunctionBytecode *b)
+{
+    ICCache *cache = (ICCache *)b->ic_slots;
+    if (likely(cache))
+        return cache;
+
+    cache = js_mallocz_rt(rt, sizeof(ICCache));
+    if (!cache)
+        return NULL;
+    b->ic_slots = (ICSlot *)cache;
+    b->ic_count = IC_HASH_SIZE;
+    return cache;
+}
+
+/*
+ * Property IC lookup - returns the property index if found, or -1 for miss.
+ * Supports polymorphic lookup across multiple shapes.
+ */
+static force_inline int prop_ic_lookup(ICCache *cache, uint32_t pc_offset, JSShape *shape)
+{
+    if (!cache)
+        return -1;
+
+    uint32_t idx = ic_hash(pc_offset);
+    PropICSlot *slot = &cache->prop_slots[idx];
+
+    /* Check if this slot is for our pc_offset */
+    if (slot->count == 0 || slot->pc_offset != pc_offset)
+        return -1;
+
+    /* Search through cached shapes (polymorphic) */
+    for (int i = 0; i < slot->count; i++) {
+        if (slot->entries[i].shape == shape) {
+            return (int)slot->entries[i].prop_idx;
+        }
+    }
+
+    return -1;  /* Shape not in cache */
+}
+
+/*
+ * Property IC update - add or update a shape->prop_idx mapping.
+ * If the slot is full (IC_POLY_SIZE entries), we go megamorphic and stop caching.
+ */
+static void prop_ic_update(JSRuntime *rt, JSFunctionBytecode *b,
+                           uint32_t pc_offset, JSShape *shape, uint32_t prop_idx)
+{
+    ICCache *cache = ic_ensure_cache(rt, b);
+    if (!cache)
+        return;
+
+    uint32_t idx = ic_hash(pc_offset);
+    PropICSlot *slot = &cache->prop_slots[idx];
+
+    /* If this is a different pc_offset (hash collision), reset the slot */
+    if (slot->count > 0 && slot->pc_offset != pc_offset) {
+        slot->count = 0;
+    }
+
+    slot->pc_offset = pc_offset;
+
+    /* Check if shape is already cached */
+    for (int i = 0; i < slot->count; i++) {
+        if (slot->entries[i].shape == shape) {
+            /* Update existing entry (prop_idx might have changed) */
+            slot->entries[i].prop_idx = prop_idx;
+            return;
+        }
+    }
+
+    /* Add new entry if we have room */
+    if (slot->count < IC_POLY_SIZE) {
+        slot->entries[slot->count].shape = shape;
+        slot->entries[slot->count].prop_idx = prop_idx;
+        slot->count++;
+    }
+    /* else: megamorphic - stop caching this site */
+}
+
+/* Legacy call IC functions - kept for future use with managed stack frames */
+static force_inline uint32_t call_ic_hash(uint32_t pc_offset)
+{
+    return ic_hash(pc_offset);
+}
+
+static force_inline CallICSlot *call_ic_lookup(void *cache,
+                                                uint32_t pc_offset,
+                                                JSObject *func_obj)
+{
+    (void)cache; (void)pc_offset; (void)func_obj;
+    return NULL;  /* Disabled until managed stack frames are implemented */
+}
+
+static void call_ic_update(JSRuntime *rt, JSFunctionBytecode *b,
+                           uint32_t pc_offset, JSObject *func_obj)
+{
+    (void)rt; (void)b; (void)pc_offset; (void)func_obj;
+    /* Disabled until managed stack frames are implemented */
+}
+
+/*
+ * Fast path for calling a C function with cached info.
+ *
+ * This sets up a minimal stack frame so that things like new Error().stack work.
+ * We avoid the overhead of js_call_c_function by:
+ * - Skipping the class_id lookup and cproto extraction (cached)
+ * - Skipping stack overflow check for common cases (caller already checked)
+ * - Inlining the most common calling conventions
+ *
+ * Returns JS_TAG_UNINITIALIZED to signal that the caller should use the slow path.
+ */
+static force_inline JSValue call_ic_invoke_native(JSContext *ctx,
+                                                   JSRuntime *rt,
+                                                   CallICSlot *slot,
+                                                   JSValueConst func_obj,
+                                                   JSValueConst this_obj,
+                                                   int argc, JSValueConst *argv,
+                                                   JSStackFrame *caller_sf)
+{
+    JSCFunctionType func = slot->u.native.c_function;
+    JSContext *realm = slot->u.native.realm;
+    int cproto = slot->u.native.cproto;
+    int16_t magic = slot->u.native.magic;
+    JSValue ret_val;
+
+    /* Set up minimal stack frame for stack traces */
+    JSStackFrame ic_sf;
+    ic_sf.prev_frame = caller_sf;
+    ic_sf.cur_func = func_obj;
+    ic_sf.arg_count = argc;
+    ic_sf.arg_buf = (JSValue *)argv;
+    ic_sf.var_buf = NULL;
+    ic_sf.cur_pc = NULL;
+    ic_sf.js_mode = 0;
+    init_list_head(&ic_sf.var_ref_list);
+
+    rt->current_stack_frame = &ic_sf;
+
+    /* Fast path for the most common calling conventions */
+    switch (cproto) {
+    case JS_CFUNC_generic:
+        ret_val = func.generic(realm, this_obj, argc, argv);
+        break;
+    case JS_CFUNC_generic_magic:
+        ret_val = func.generic_magic(realm, this_obj, argc, argv, magic);
+        break;
+    case JS_CFUNC_getter:
+        ret_val = func.getter(realm, this_obj);
+        break;
+    case JS_CFUNC_getter_magic:
+        ret_val = func.getter_magic(realm, this_obj, magic);
+        break;
+    case JS_CFUNC_setter:
+        ret_val = func.setter(realm, this_obj, argc > 0 ? argv[0] : JS_NULL);
+        break;
+    case JS_CFUNC_setter_magic:
+        ret_val = func.setter_magic(realm, this_obj, argc > 0 ? argv[0] : JS_NULL, magic);
+        break;
+    default:
+        /* Fall back to full path for less common calling conventions */
+        rt->current_stack_frame = caller_sf;
+        return (JSValue){ .u.int32 = 0, .tag = JS_TAG_UNINITIALIZED };
+    }
+
+    rt->current_stack_frame = caller_sf;
+    return ret_val;
+}
+
 #define JS_CALL_FLAG_COPY_ARGV   (1 << 1)
 
 static JSValue js_call_c_function(JSContext *ctx, JSValueConst func_obj,
@@ -13468,6 +13717,10 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
         CASE(OP_call_method):
         CASE(OP_tail_call_method):
             {
+#define CALL_IC_ENABLED 0  /* Set to 1 to enable Call IC */
+#if CALL_IC_ENABLED
+                const uint8_t *call_pc = pc - 1;  /* PC of opcode for IC */
+#endif
                 call_argc = get_u16(pc);
                 pc += 2;
                 call_argv = sp - call_argc;
@@ -13476,6 +13729,44 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
                 /* Record call site */
                 profile_record_call_site(rt, b, (uint32_t)(pc - b->byte_code_buf));
 #endif
+#if CALL_IC_ENABLED
+                /* Call IC fast path for C functions */
+                {
+                    JSValue func_val = call_argv[-1];
+                    JSValue this_val = call_argv[-2];
+
+                    if (likely(JS_VALUE_GET_TAG(func_val) == JS_TAG_OBJECT)) {
+                        JSObject *func_obj = JS_VALUE_GET_OBJ(func_val);
+                        uint32_t pc_offset = (uint32_t)(call_pc - b->byte_code_buf);
+                        CallICCache *cache = (CallICCache *)b->ic_slots;
+                        CallICSlot *ic_slot = call_ic_lookup(cache, pc_offset, func_obj);
+
+                        if (ic_slot && ic_slot->is_native) {
+                            /* IC hit for native function - use fast path with proper stack frame */
+                            ret_val = call_ic_invoke_native(ctx, rt, ic_slot, func_val, this_val,
+                                                             call_argc, (JSValueConst *)call_argv, sf);
+                            if (likely(JS_VALUE_GET_TAG(ret_val) != JS_TAG_UNINITIALIZED)) {
+                                /* Fast path succeeded */
+                                if (unlikely(JS_IsException(ret_val)))
+                                    goto exception;
+                                if (opcode == OP_tail_call_method)
+                                    goto done;
+                                for(i = -2; i < call_argc; i++)
+                                    JS_FreeValue(ctx, call_argv[i]);
+                                sp -= call_argc + 2;
+                                *sp++ = ret_val;
+                                BREAK;
+                            }
+                            /* JS_TAG_UNINITIALIZED means fall through to slow path */
+                        } else if (!ic_slot && (func_obj->class_id == JS_CLASS_C_FUNCTION ||
+                                                func_obj->class_id == JS_CLASS_BYTECODE_FUNCTION)) {
+                            /* IC miss - populate cache for next time */
+                            call_ic_update(rt, b, pc_offset, func_obj);
+                        }
+                    }
+                }
+#endif
+                /* Slow path: use regular call machinery */
                 ret_val = JS_CallInternal_OLD(ctx, call_argv[-1], call_argv[-2],
                                           JS_NULL, call_argc, call_argv, 0);
                 if (unlikely(JS_IsException(ret_val)))
@@ -14300,9 +14591,9 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
                 JSValue val;
                 JSAtom atom;
                 JSValue obj;
-                const uint8_t *ic_pc;
+                uint32_t pc_offset;
 
-                ic_pc = pc - 1;  /* PC of opcode, before consuming operands */
+                pc_offset = (uint32_t)((pc - 1) - b->byte_code_buf);
                 atom = get_u32(pc);
                 pc += 4;
 
@@ -14313,53 +14604,41 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
 #endif
                 obj = sp[-1];
 
-                /* Monomorphic IC fast path: shape-guarded own-property lookup */
+                /* Per-function polymorphic IC fast path */
                 if (likely(JS_VALUE_GET_TAG(obj) == JS_TAG_OBJECT)) {
                     JSObject *p = JS_VALUE_GET_OBJ(obj);
                     JSShape *sh = p->shape;
+                    ICCache *cache = (ICCache *)b->ic_slots;
 
-                    /* Simple thread-local IC cache using PC as key */
-                    static __thread struct {
-                        const uint8_t *pc;
-                        JSShape *shape;
-                        uint32_t prop_idx;
-                        JSAtom atom;
-                    } ic_cache[256];
+                    /* IC lookup - supports multiple shapes per site */
+                    int prop_idx = prop_ic_lookup(cache, pc_offset, sh);
+                    if (likely(prop_idx >= 0)) {
+                        JSShapeProperty *prs = &get_shape_prop(sh)[prop_idx];
 
-                    uint32_t cache_idx = ((uintptr_t)ic_pc >> 3) & 255;
-                    struct { const uint8_t *pc; JSShape *shape; uint32_t prop_idx; JSAtom atom; } *slot = &ic_cache[cache_idx];
-
-                    /* IC hit: shape guard passed */
-                    if (likely(slot->pc == ic_pc && slot->shape == sh && slot->atom == atom)) {
-                        JSProperty *pr = &p->prop[slot->prop_idx];
-                        JSShapeProperty *prs = &get_shape_prop(sh)[slot->prop_idx];
-
-                        /* Double-check it's still a normal data property */
+                        /* Verify it's still a normal data property */
                         if (likely((prs->flags & JS_PROP_TMASK) == JS_PROP_NORMAL)) {
+                            JSProperty *pr = &p->prop[prop_idx];
                             val = JS_DupValue(ctx, pr->u.value);
                             JS_FreeValue(ctx, obj);
                             sp[-1] = val;
-                            goto get_field_done;
+                            BREAK;
                         }
                     }
 
-                    /* IC miss: do lookup and populate cache if it's an own data property */
+                    /* IC miss: do lookup and update cache if it's an own data property */
                     {
                         JSProperty *pr;
                         JSShapeProperty *prs = find_own_property(&pr, p, atom);
 
                         if (prs && (prs->flags & JS_PROP_TMASK) == JS_PROP_NORMAL) {
-                            /* Cache this for next time */
-                            uint32_t prop_idx = prs - get_shape_prop(sh);
-                            slot->pc = ic_pc;
-                            slot->shape = sh;
-                            slot->prop_idx = prop_idx;
-                            slot->atom = atom;
+                            /* Update cache for next time */
+                            uint32_t idx = prs - get_shape_prop(sh);
+                            prop_ic_update(rt, b, pc_offset, sh, idx);
 
                             val = JS_DupValue(ctx, pr->u.value);
                             JS_FreeValue(ctx, obj);
                             sp[-1] = val;
-                            goto get_field_done;
+                            BREAK;
                         }
                     }
                 }
@@ -14370,8 +14649,6 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
                     goto exception;
                 JS_FreeValue(ctx, sp[-1]);
                 sp[-1] = val;
-            get_field_done:
-                ;
             }
             BREAK;
 
@@ -14380,9 +14657,9 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
                 JSValue val;
                 JSAtom atom;
                 JSValue obj;
-                const uint8_t *ic_pc;
+                uint32_t pc_offset;
 
-                ic_pc = pc - 1;
+                pc_offset = (uint32_t)((pc - 1) - b->byte_code_buf);
                 atom = get_u32(pc);
                 pc += 4;
 
@@ -14393,57 +14670,48 @@ static JSValue JS_CallInternal_OLD(JSContext *caller_ctx, JSValueConst func_obj,
 #endif
                 obj = sp[-1];
 
-                /* Monomorphic IC fast path */
+                /* Per-function polymorphic IC fast path */
                 if (likely(JS_VALUE_GET_TAG(obj) == JS_TAG_OBJECT)) {
                     JSObject *p = JS_VALUE_GET_OBJ(obj);
                     JSShape *sh = p->shape;
+                    ICCache *cache = (ICCache *)b->ic_slots;
 
-                    static __thread struct {
-                        const uint8_t *pc;
-                        JSShape *shape;
-                        uint32_t prop_idx;
-                        JSAtom atom;
-                    } ic_cache2[256];
-
-                    uint32_t cache_idx = ((uintptr_t)ic_pc >> 3) & 255;
-                    struct { const uint8_t *pc; JSShape *shape; uint32_t prop_idx; JSAtom atom; } *slot = &ic_cache2[cache_idx];
-
-                    if (likely(slot->pc == ic_pc && slot->shape == sh && slot->atom == atom)) {
-                        JSProperty *pr = &p->prop[slot->prop_idx];
-                        JSShapeProperty *prs = &get_shape_prop(sh)[slot->prop_idx];
+                    /* IC lookup - supports multiple shapes per site */
+                    int prop_idx = prop_ic_lookup(cache, pc_offset, sh);
+                    if (likely(prop_idx >= 0)) {
+                        JSShapeProperty *prs = &get_shape_prop(sh)[prop_idx];
 
+                        /* Verify it's still a normal data property */
                         if (likely((prs->flags & JS_PROP_TMASK) == JS_PROP_NORMAL)) {
+                            JSProperty *pr = &p->prop[prop_idx];
                             val = JS_DupValue(ctx, pr->u.value);
                             *sp++ = val;
-                            goto get_field2_done;
+                            BREAK;
                         }
                     }
 
+                    /* IC miss: do lookup and update cache if it's an own data property */
                     {
                         JSProperty *pr;
                         JSShapeProperty *prs = find_own_property(&pr, p, atom);
 
                         if (prs && (prs->flags & JS_PROP_TMASK) == JS_PROP_NORMAL) {
-                            uint32_t prop_idx = prs - get_shape_prop(sh);
-                            slot->pc = ic_pc;
-                            slot->shape = sh;
-                            slot->prop_idx = prop_idx;
-                            slot->atom = atom;
+                            /* Update cache for next time */
+                            uint32_t idx = prs - get_shape_prop(sh);
+                            prop_ic_update(rt, b, pc_offset, sh, idx);
 
                             val = JS_DupValue(ctx, pr->u.value);
                             *sp++ = val;
-                            goto get_field2_done;
+                            BREAK;
                         }
                     }
                 }
 
-                /* Slow path */
+                /* Slow path: proto chain, getters, non-objects, etc. */
                 val = JS_GetProperty(ctx, obj, atom);
                 if (unlikely(JS_IsException(val)))
                     goto exception;
                 *sp++ = val;
-            get_field2_done:
-                ;
             }
             BREAK;
 
@@ -25522,35 +25790,6 @@ static JSValue js_create_function(JSContext *ctx, JSFunctionDef *fd)
     return JS_EXCEPTION;
 }
 
-/* IC helper functions */
-static ICSlot *ic_get_slot(JSFunctionBytecode *b, uint32_t ic_index)
-{
-  if (ic_index >= b->ic_count)
-    return NULL;
-  return &b->ic_slots[ic_index];
-}
-
-static void ic_init_call(ICSlot *slot)
-{
-  memset(slot, 0, sizeof(*slot));
-  slot->kind = IC_CALL;
-  slot->state = IC_STATE_UNINIT;
-}
-
-static void ic_init_get_prop(ICSlot *slot)
-{
-  memset(slot, 0, sizeof(*slot));
-  slot->kind = IC_GET_PROP;
-  slot->state = IC_STATE_UNINIT;
-}
-
-static void ic_init_set_prop(ICSlot *slot)
-{
-  memset(slot, 0, sizeof(*slot));
-  slot->kind = IC_SET_PROP;
-  slot->state = IC_STATE_UNINIT;
-}
-
 static void free_function_bytecode(JSRuntime *rt, JSFunctionBytecode *b)
 {
     int i;

test.ce

@@ -5,6 +5,8 @@ var time = use('time')
 var json = use('json')
 var blob = use('blob')
 
+log.console("here")
+
 if (!args) args = []
 
 var target_pkg = null // null = current package

tests/suite.cm

@@ -2,6 +2,7 @@
 // Tests all core features before implementing performance optimizations
 // (bytecode passes, ICs, quickening, tail call optimization)
 //
+
 return {
     // ============================================================================
     // ARITHMETIC OPERATORS - Numbers