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Use sess.opts.optimize instead of sess.opts.cg.opt_level for LTO optlevel #22530

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Merged
merged 2 commits into from
Feb 25, 2015
Merged

Use sess.opts.optimize instead of sess.opts.cg.opt_level for LTO optlevel #22530

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dc3bc90
Use sess.opts.optimize instead of sess.opts.cg.opt_level for LTO optl…
rprichard Feb 19, 2015
9167c62
Disable run-pass/sepcomp-lib-lto.rs on Android until #18800 is fixed
rprichard Feb 24, 2015
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7 changes: 6 additions & 1 deletion src/librustc_trans/back/lto.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -167,7 +167,12 @@ pub fn run(sess: &session::Session, llmod: ModuleRef,
llvm::LLVMRustAddAnalysisPasses(tm, pm, llmod);
llvm::LLVMRustAddPass(pm, "verify\0".as_ptr() as *const _);

let opt = sess.opts.cg.opt_level.unwrap_or(0) as libc::c_uint;
let opt = match sess.opts.optimize {
config::No => 0,
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It looks like -Clto without optimizations doesn't even perform dead code elimination, which makes LTO rather pointless, IMO.
Can we please make -Clto imply -Copt-level=2? (unless specified explicitly, of course)

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While perhaps not super useful, it does allow varying axes of configuration as well as perhaps a smoke test of some form. I would be ok, however, to have -Clto switch the default optimization level as ell though.

config::Less => 1,
config::Default => 2,
config::Aggressive => 3,
};

let builder = llvm::LLVMPassManagerBuilderCreate();
llvm::LLVMPassManagerBuilderSetOptLevel(builder, opt);
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1 change: 1 addition & 0 deletions src/test/run-pass/sepcomp-lib-lto.rs
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Expand Up @@ -14,6 +14,7 @@
// aux-build:sepcomp_lib.rs
// compile-flags: -C lto
// no-prefer-dynamic
// ignore-android FIXME #18800

extern crate sepcomp_lib;
use sepcomp_lib::a::one;
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