feat(t27b): bench prose clauses lower to nothing; scalar fields set from a call - #6293
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…rom a call A bench written as prose clauses (`measure: nanoseconds to f(x)`, `target: < 100ns`) reaches lowering as childless StmtExpr nodes named `<clause>:`. t27c's Zig backend writes `// NOT LOWERED: empty statement` for each inside a bench fn nothing calls; t27b now lowers them to nothing inside a bench body and keeps rejecting them anywhere else. This is the largest of three unrelated StmtExpr shapes (89 of 104 files); top-level statements and the dotted-module stray `.b` stay rejected. Unblocking those files exposed two JIT/interpreter mismatches: a scalar struct field initialised from a call took the in-place path meant for an aggregate result and was never written. Lower::init now builds in place only for an aggregate type. Corpus: pass 223 -> 246, fail 3 -> 4 (gf16_dot4, same as the reference), rejected 711 -> 687, mismatch 0. Closes #6291 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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Closes #6291
Refs #6063
What
StmtExprled the greedy order (+28 files) after #6289. Read per file it is three unrelated shapes; this PR takes the largest:empty statement: bench prose clause (measure: ...,target: < 100ns).bfrom a dottedmodule a.b;<clause>:; t27c's Zig backend writes// NOT LOWERED: empty statement -- statement rendered to nothing (T43)inside abench_<name>fn nothing calls. t27b lowers it to nothing only inside a bench body; outside one it stays a named rejection, so no test clause can be dropped silently.Lower::init, a scalar struct field initialised from a call (Out{ .result = mul(a, b) }) took the in-place path meant for an aggregate result (the call got a result pointer and the field was never written).in_placenow requiresis_agg(&t). Fixed here because the family cannot land with a mismatch.Tests
differential::bench_prose_clauses_lower_to_nothingsource::struct_field_initialised_from_a_scalar_call(negative control: fails with the oldin_place)cargo test -p t27b --release: all green.t27b corpus specs(master 47621f4 vs this branch, local, load avg ~16-20)24 files changed verdict, checked one by one with
t27c test-report(t27c built from the same master):intermediate_structureoverflows u16; the reference fails exactly that test (3 pass / 1 fail).count + 1abovevar count, filed as gen-zig CSE hoistscount + 1abovevar countand across its reassignment #6292;.align = 4, Generated Zig writes .align = 4, and align is a reserved word #4807). They stay outside the honest denominator.Greedy top 5 after:
StmtAssign(undeclared)+24,ExprCall(assert with message)+19,ExprIdentifier statement+18,FnDecl+15,ExprBinary statement+12. The remainingStmtExpr(15 files: top-level statements and dotted module names) drops to greedy step 30 (+7).The ratchet ledger
docs/reports/t27b_expectations.jsonis not touched here; the steward blesses it.🤖 Generated with Claude Code