meta: Move the Criterion dependency behind a walltime feature

Currently Criterion is always built with the test crates, but it doesn't
really need to be. It wasn't a problem before but did start showing up
with the latest version bump since it added a C dependency, and for the
Miri CI runs we don't have the C toolchains. To resolve this and speed
up compilation time, move criterion behind a new feature `walltime`.

I'd rather have named this `runtime` but don't want to confuse my future
self with "what runtime?".

Author: tgross35

.github/workflows/main.yaml

@@ -287,7 +287,7 @@ jobs:
         path: ${{ env.BASELINE_NAME }}.tar.xz
 
     - name: Run wall time benchmarks
-      run: ./ci/bench-runtime.sh
+      run: ./ci/bench-walltime.sh
 
     - name: Print test logs if available
       if: always()

builtins-test/Cargo.toml

@@ -16,11 +16,11 @@ rand_xoshiro.workspace = true
 # To compare float builtins against
 rustc_apfloat.workspace = true
 
-# Really a dev dependency, but dev dependencies can't be optional
+# Really dev dependencies, but those can't be optional
+criterion = { workspace = true, optional = true }
 gungraun = { workspace = true, optional = true }
 
 [dev-dependencies]
-criterion.workspace = true
 paste.workspace = true
 
 [target.'cfg(all(target_arch = "arm", not(any(target_env = "gnu", target_env = "musl")), target_os = "linux"))'.dev-dependencies]
@@ -46,8 +46,10 @@ no-sys-f16 = ["no-sys-f16-f64-convert"]
 # Enable icount benchmarks (requires gungraun-runner and valgrind locally)
 icount = ["dep:gungraun"]
 
-# Enable report generation without bringing in more dependencies by default
-benchmarking-reports = ["criterion/plotters", "criterion/html_reports"]
+# Config for wall time benchmarks. Plotters and html_reports bring in extra
+# deps so are off by default for CI.
+benchmarking-reports = ["walltime", "criterion/plotters", "criterion/html_reports"]
+walltime = ["dep:criterion"]
 
 # NOTE: benchmarks must be run with `--no-default-features` or with
 # `-p builtins-test`, otherwise the default `compiler-builtins` feature
@@ -57,38 +59,47 @@ benchmarking-reports = ["criterion/plotters", "criterion/html_reports"]
 [[bench]]
 name = "float_add"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_sub"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_mul"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_div"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_cmp"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_conv"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_extend"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_trunc"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "float_pow"
 harness = false
+required-features = ["walltime"]
 
 [[bench]]
 name = "mem_icount"

ci/bench-runtime.sh ci/bench-walltime.shci/bench-runtime.sh renamed to ci/bench-walltime.sh

@@ -6,4 +6,4 @@
 export LIBM_SEED=benchesbenchesbenchesbencheswoo!
 cargo bench --package libm-test \
     --no-default-features \
-    --features short-benchmarks,build-musl,libm/force-soft-floats
+    --features walltime,short-benchmarks,build-musl,libm/force-soft-floats

libm-test/Cargo.toml

@@ -9,7 +9,6 @@ license = "MIT OR Apache-2.0"
 anyhow.workspace = true
 # This is not directly used but is required so we can enable `gmp-mpfr-sys/force-cross`.
 gmp-mpfr-sys = { workspace = true, optional = true }
-gungraun = { workspace = true, optional = true }
 indicatif.workspace = true
 libm = { workspace = true, default-features = true, features = ["unstable-public-internals"] }
 libm-macros.workspace = true
@@ -20,14 +19,17 @@ rand_chacha.workspace = true
 rayon.workspace = true
 rug = { workspace = true, optional = true }
 
+# Really dev dependencies, but those can't be optional
+criterion = { workspace = true, optional = true }
+gungraun = { workspace = true, optional = true }
+
 [target.'cfg(target_family = "wasm")'.dependencies]
 getrandom = { workspace = true, features = ["wasm_js"] }
 
 [build-dependencies]
 rand = { workspace = true, optional = true }
 
 [dev-dependencies]
-criterion.workspace = true
 libtest-mimic.workspace = true
 
 [features]
@@ -43,8 +45,10 @@ build-mpfr = ["dep:rug", "dep:gmp-mpfr-sys"]
 # Build our own musl for testing and benchmarks
 build-musl = ["dep:musl-math-sys"]
 
-# Enable report generation without bringing in more dependencies by default
-benchmarking-reports = ["criterion/plotters", "criterion/html_reports"]
+# Config for wall time benchmarks. Plotters and html_reports bring in extra
+# deps so are off by default for CI.
+benchmarking-reports = ["walltime", "criterion/plotters", "criterion/html_reports"]
+walltime = ["dep:criterion"]
 
 # Enable icount benchmarks (requires gungraun-runner and valgrind locally)
 icount = ["dep:gungraun"]
@@ -60,6 +64,7 @@ required-features = ["icount"]
 [[bench]]
 name = "random"
 harness = false
+required-features = ["walltime"]
 
 [[test]]
 # No harness so that we can skip tests at runtime based on env. Prefixed with