================
@@ -490,6 +490,35 @@ void tools::AddLinkerInputs(const ToolChain &TC, const
InputInfoList &Inputs,
else
A.renderAsInput(Args, CmdArgs);
}
+ if (const Arg *A = Args.getLastArg(options::OPT_fveclib)) {
+ const llvm::Triple &Triple = TC.getTriple();
+ StringRef V = A->getValue();
+ if (V == "ArmPL" && (Triple.isOSLinux() || Triple.isOSDarwin())) {
+ // To support -fveclib=ArmPL we need to link against libamath.
+ // Some of the libamath functions depend on libm, at the same time,
+ // libamath exports its own implementation of some of the libm
+ // functions. Since here we are interested only in the subset of
+ // libamath functions that is covered by the veclib mappings,
+ // we need to do the following:
+ //
+ // 1. On Linux, link only when actually needed.
+ //
+ // 2. Prefer libm functions over libamath.
+ //
+ // 3. Link against libm to resolve libamath dependencies.
+ //
+ if (Triple.isOSLinux()) {
+ CmdArgs.push_back(Args.MakeArgString("--push-state"));
+ CmdArgs.push_back(Args.MakeArgString("--as-needed"));
+ }
+ CmdArgs.push_back(Args.MakeArgString("-lm"));
----------------
pawosm-arm wrote:
No no, it isn't simply a dependency. It's a matter of prioritizing system-libm
over libamath which contains faster (and potentially less accurate)
implementations of some of the libm functions. I was advised, these should not
be used in normal circumstances (it is just unfortunate that for historical
reasons, this veclib provider isn't just veclib provider; but for
-fveclib=ArmPL there is no other, and likely there will be no other). From the
other side, some of the libamath-only functions depend on libm functions that
are not in libamath. Is it certain that start/end-group algorithm would look
into libraries in-order preferring library first to provide looked upon symbol
(e.g. when given `--start-group -lm -lamath --end-group`)? Besides, Darwin's
default ld doesn't seem to support --start-group.
https://github.com/llvm/llvm-project/pull/116432
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