JIT doesn't trace exec()-generated functions called from hot loops

When a hot loop calls functions generated via exec(), the loop body gets traced but the callees don't. Each callee is individually cold (called ~60 times), but the call site is hot (5,000+ calls total across different callees).

Concrete case: tinygrad generates ~5,000 pattern matching functions at startup via exec(). They're called from a tight loop:

for _, match, _ in pats:
    if (ret := match(uop, ctx)) is not None: return ret

PYTHON_JIT=1 on 3.14.4 produces no improvement. The specializer works (LOAD_ATTR_SLOT fires correctly), but the JIT never compiles the callees.

Related: faster-cpython/ideas#738, #118093 (tier 2 entry at function calls).

It would be useful to either trace through exec()-generated callees at hot call sites, or detect aggregate hotness across callees sharing a call site.

Linked PRs

• gh-149575

首先，在 Python 3.14.4 上使用 PYTHON_JIT=1 重現 tinygrad 的模式匹配迴圈，重點關注由 exec() 產生的被呼叫方以及它們共用的熱門呼叫點。將 specializer 的 LOAD_ATTR_SLOT 行為與被呼叫方是否被編譯進行比較；當回報的熱門呼叫工作負載顯示透過產生的函式獲得了 JIT 改善時，即表示完成。