t27b: @compileAssert as assert, integer as f64 as @floatFromInt (+10 counted) - #6322
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ExprCall(@compileAssert) was the only listed lab blocker on 9 specs the
reference passes (specs/numeric/gf{6,10,14,48,96,128,256,512,1024}.t27).
t27c's Zig backend lowers `@compileAssert` through the same arm as
`assert` (`if (!(cond))`; a false one fails the compile inside an
invariant's comptime block and is a runtime check inside a test), so
t27b now does the same, with the same string-literal message rule.
The 9 files then stopped at `EXP_BITS as f64`. The reference emits
`@as(f64, @floatFromInt(x))` for an integer operand, so an integer
`as f64` now lowers as @floatFromInt with result type f64. Float or
bool `as f64` and f64 `as` an integer stay refused as ExprCast(f64).
t27b corpus specs --reference (t27c built from 65e6ddb): checked
passes among the 720 reference passes 307 -> 317 (the 9 gf files and
specs/queen/task_analysis.t27), mismatch 0, no new pass where the
reference fails.
Closes #6319
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Contributor
This was referenced Oct 5, 2026
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Closes #6319
Refs #6063
What
@compileAssert(cond[, "msg"])lowers through the same arm asassertincli/t27b/src/lower.rs. The reason: t27c's Zig backend does exactly that (node.name == "@compileAssert" || node.name == "assert"inbootstrap/src/compiler.rs). It emitsif (!(cond)) <fail>. Inside aninvariant(acomptimeblock) a false condition fails the compile. Inside atestit is a runtime check.x as f64with an integerxlowers as@floatFromIntwith result type f64. The reference emits@as(f64, @floatFromInt(x))for it (is_float_exprfalse). A float or bool operand, and f64asan integer, stay refused asExprCast(f64).The lab (0851055) listed
ExprCall(@compileAssert)as the only blocker on 9 specs the reference passes. That list was incomplete. With@compileAssertlowered, all 9 stopped next atEXP_BITS as f64, so this PR also covers that second blocker.Verdicts vs the reference (mutation control)
@compileAssertin invariant / test@compileAssertin a test@compileAssertin an invariant (int and f64 operands, mutated gf10)error: assertion failed(comptime)Neither path passes a file with a false invariant. The failure class is different, though: the reference fails to compile, t27b fails at run time.
assertin an invariant already behaves this way in t27b. Fixing it would need a "does not compile" outcome in t27b, which is out of this PR's scope.Corpus (
t27b corpus specs --blockers --reference <t27c built from 65e6ddba3>, local, load 7-36)Counted gain: +10. The 9
specs/numeric/gf{6,10,14,48,96,128,256,512,1024}.t27(4-6 invariants each, now run) plusspecs/queen/task_analysis.t27(priority as f64). All 10 are reference-pass and t27bpass. JIT and interpreter agree.Reference-backed greedy top 5 after:
ConstDecl(str field)+5,ExprLiteral(char literal)+4,ExprIf+5,StmtExpr+4,ExprArrayLiteral+4.Tests
compile_assert_is_assert(cli/t27b/tests/source.rs) covers true and false, invariant and test, f64 operands from integer casts, and the message rule. Its source was also run throught27c test-report. With the broken invariant it is BLOCKED; without it, 1 of 2 tests fail. Both match.f64_refusals_name_the_constructnow refusesx as f64(f64 operand),x as i32and(n > 0) as f64by name.cargo test -p t27b: all green.🤖 Generated with Claude Code