From f5f067bf9d8de86f3a546a33d8a2e08dfa64cde1 Mon Sep 17 00:00:00 2001 From: Martin Nordholts Date: Sat, 4 May 2024 16:21:50 +0200 Subject: [PATCH] Deprecate no-op codegen option `-Cinline-threshold=...` This deprecates `-Cinline-threshold` since using it has no effect. This has been the case since the new LLVM pass manager started being used, more than 2 years ago. --- compiler/rustc_codegen_llvm/src/back/write.rs | 3 --- compiler/rustc_driver_impl/src/lib.rs | 4 ++++ compiler/rustc_session/src/options.rs | 3 ++- src/doc/rustc/src/codegen-options/index.md | 15 ++------------- tests/ui/codegen/issue-82833-slice-miscompile.rs | 2 +- .../ui/deprecation/deprecated_inline_threshold.rs | 4 ++++ .../deprecated_inline_threshold.stderr | 2 ++ 7 files changed, 15 insertions(+), 18 deletions(-) create mode 100644 tests/ui/deprecation/deprecated_inline_threshold.rs create mode 100644 tests/ui/deprecation/deprecated_inline_threshold.stderr diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs index 02e3bb06dda..afacd0994b5 100644 --- a/compiler/rustc_codegen_llvm/src/back/write.rs +++ b/compiler/rustc_codegen_llvm/src/back/write.rs @@ -564,9 +564,6 @@ pub(crate) unsafe fn llvm_optimize( let llvm_plugins = config.llvm_plugins.join(","); - // FIXME: NewPM doesn't provide a facility to pass custom InlineParams. - // We would have to add upstream support for this first, before we can support - // config.inline_threshold and our more aggressive default thresholds. let result = llvm::LLVMRustOptimize( module.module_llvm.llmod(), &*module.module_llvm.tm, diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs index f7828b033bb..c51244a2c78 100644 --- a/compiler/rustc_driver_impl/src/lib.rs +++ b/compiler/rustc_driver_impl/src/lib.rs @@ -1136,6 +1136,10 @@ pub fn describe_flag_categories(early_dcx: &EarlyDiagCtxt, matches: &Matches) -> early_dcx.early_warn("the `-Cno-stack-check` flag is deprecated and does nothing"); } + if cg_flags.iter().any(|x| x.starts_with("inline-threshold")) { + early_dcx.early_warn("the `-Cinline-threshold` flag is deprecated and does nothing (consider using `-Cllvm-args=--inline-threshold=...`)"); + } + if cg_flags.iter().any(|x| *x == "passes=list") { let backend_name = debug_flags.iter().find_map(|x| x.strip_prefix("codegen-backend=")); diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index fd4a3a9e6ce..2382412ee1a 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -1485,7 +1485,8 @@ pub(crate) fn parse_wasm_c_abi(slot: &mut WasmCAbi, v: Option<&str>) -> bool { incremental: Option = (None, parse_opt_string, [UNTRACKED], "enable incremental compilation"), inline_threshold: Option = (None, parse_opt_number, [TRACKED], - "set the threshold for inlining a function"), + "this option is deprecated and does nothing \ + (consider using `-Cllvm-args=--inline-threshold=...`)"), #[rustc_lint_opt_deny_field_access("use `Session::instrument_coverage` instead of this field")] instrument_coverage: InstrumentCoverage = (InstrumentCoverage::No, parse_instrument_coverage, [TRACKED], "instrument the generated code to support LLVM source-based code coverage reports \ diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md index babe2bc342b..cd10168bc1c 100644 --- a/src/doc/rustc/src/codegen-options/index.md +++ b/src/doc/rustc/src/codegen-options/index.md @@ -184,20 +184,9 @@ incremental files will be stored. ## inline-threshold -This option lets you set the default threshold for inlining a function. It -takes an unsigned integer as a value. Inlining is based on a cost model, where -a higher threshold will allow more inlining. +This option is deprecated and does nothing. -The default depends on the [opt-level](#opt-level): - -| opt-level | Threshold | -|-----------|-----------| -| 0 | N/A, only inlines always-inline functions | -| 1 | N/A, only inlines always-inline functions and LLVM lifetime intrinsics | -| 2 | 225 | -| 3 | 275 | -| s | 75 | -| z | 25 | +Consider using `-Cllvm-args=--inline-threshold=...`. ## instrument-coverage diff --git a/tests/ui/codegen/issue-82833-slice-miscompile.rs b/tests/ui/codegen/issue-82833-slice-miscompile.rs index 7723679dab1..32eac923a63 100644 --- a/tests/ui/codegen/issue-82833-slice-miscompile.rs +++ b/tests/ui/codegen/issue-82833-slice-miscompile.rs @@ -1,5 +1,5 @@ //@ run-pass -//@ compile-flags: -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Copt-level=0 -Cdebuginfo=2 +//@ compile-flags: -Ccodegen-units=1 -Cllvm-args=--inline-threshold=0 -Clink-dead-code -Copt-level=0 -Cdebuginfo=2 // Make sure LLVM does not miscompile this. diff --git a/tests/ui/deprecation/deprecated_inline_threshold.rs b/tests/ui/deprecation/deprecated_inline_threshold.rs new file mode 100644 index 00000000000..56e033b8cf5 --- /dev/null +++ b/tests/ui/deprecation/deprecated_inline_threshold.rs @@ -0,0 +1,4 @@ +//@ check-pass +//@ compile-flags: -Cinline-threshold=666 + +fn main() {} diff --git a/tests/ui/deprecation/deprecated_inline_threshold.stderr b/tests/ui/deprecation/deprecated_inline_threshold.stderr new file mode 100644 index 00000000000..c4f8ff092b2 --- /dev/null +++ b/tests/ui/deprecation/deprecated_inline_threshold.stderr @@ -0,0 +1,2 @@ +warning: the `-Cinline-threshold` flag is deprecated and does nothing (consider using `-Cllvm-args=--inline-threshold=...`) +