Update bootstrap tfp to --skip-huge instead of listing tests

src/bootstrap/src/core/build_steps/test.rs

@@ -3533,13 +3533,9 @@ impl Step for TestFloatParse {
 
         cargo_run.arg("--");
         if builder.config.args().is_empty() {
-            builder.info("only running a subset of tests by default");
             // By default, exclude tests that take longer than ~1m.
-            cargo_run
-                .args(["--exclude", "fuzz"])
-                .args(["--exclude", "exhaustive"])
-                .args(["--exclude", "large exp"])
-                .args(["--exclude", "rand digits"]);
+            builder.info("only running a subset of tests by default");
+            cargo_run.arg("--skip-huge");
         } else {
             cargo_run.args(builder.config.args());
         }

src/etc/test-float-parse/README.md

@@ -7,20 +7,20 @@ The generators work as follows:
 
 - Each generator is a struct that lives somewhere in the `gen` module. Usually
   it is generic over a float type.
-- These generators must implement `Iterator`, which should return a context
-  type that can be used to construct a test string (but usually not the string
+- These generators must implement `Iterator`, which should return a context type
+  that can be used to construct a test string (but usually not the string
   itself).
 - They must also implement the `Generator` trait, which provides a method to
   write test context to a string as a test case, as well as some extra metadata.
-  
-  The split between context generation and string construction is so that
-  we can reuse string allocations.
+
+  The split between context generation and string construction is so that we can
+  reuse string allocations.
 - Each generator gets registered once for each float type. All of these
   generators then get iterated, and each test case checked against the float
   type's parse implementation.
 
-Some tests produce decimal strings, others generate bit patterns that need
-to convert to the float type before printing to a string. For these, float to
+Some tests produce decimal strings, others generate bit patterns that need to
+convert to the float type before printing to a string. For these, float to
 decimal (`flt2dec`) conversions get tested, if unintentionally.
 
 For each test case, the following is done:
@@ -30,13 +30,16 @@ For each test case, the following is done:
 - The test string is parsed separately to a `BigRational`, which acts as a
   representation with infinite precision.
 - The rational value then gets checked that it is within the float's
-  representable values (absolute value greater than the smallest number to
-  round to zero, but less less than the first value to round to infinity). If
-  these limits are exceeded, check that the parsed float reflects that.
-- For real nonzero numbers, the parsed float is converted into a
-  rational using `significand * 2^exponent`. It is then checked against the
-  actual rational value, and verified to be within half a bit's precision
-  of the parsed value.
+  representable values (absolute value greater than the smallest number to round
+  to zero, but less less than the first value to round to infinity). If these
+  limits are exceeded, check that the parsed float reflects that.
+- For real nonzero numbers, the parsed float is converted into a rational using
+  `significand * 2^exponent`. It is then checked against the actual rational
+  value, and verified to be within half a bit's precision of the parsed value.
 
 This is all highly parallelized with `rayon`; test generators can run in
 parallel, and their tests get chunked and run in parallel.
+
+There is a simple command line that allows filtering which tests are run,
+setting the number of iterations for fuzzing tests, limiting failures, setting
+timeouts, etc. See `main.rs` or run with `--help` for options.

src/etc/test-float-parse/src/lib.rs

@@ -36,7 +36,8 @@ mod gen {
 pub const DEFAULT_FUZZ_COUNT: u64 = u32::MAX as u64;
 
 /// If there are more tests than this threashold, the test will be defered until after all
-/// others run (so as to avoid thread pool starvation).
+/// others run (so as to avoid thread pool starvation). They also can be excluded with
+/// `--skip-huge`.
 const HUGE_TEST_CUTOFF: u64 = 5_000_000;
 
 /// Seed for tests that use a deterministic RNG.