Chad and I talked about this off-list (my fault!) a couple of weeks ago; finally moving this to an actual review thread.
> On 2016-Jan-06, at 06:35, Chad Rosier via cfe-commits > <cfe-commits@lists.llvm.org> wrote: > > Author: mcrosier > Date: Wed Jan 6 08:35:46 2016 > New Revision: 256937 > > URL: http://llvm.org/viewvc/llvm-project?rev=256937&view=rev > Log: > [Driver] Add support for -fno-builtin-foo options. > > Addresses PR4941 and rdar://6756912. > http://reviews.llvm.org/D15195 > > Modified: > cfe/trunk/include/clang/Basic/Builtins.h > cfe/trunk/include/clang/Basic/LangOptions.h > cfe/trunk/include/clang/Driver/Options.td > cfe/trunk/include/clang/Frontend/CodeGenOptions.h > cfe/trunk/lib/Basic/Builtins.cpp > cfe/trunk/lib/Basic/LangOptions.cpp > cfe/trunk/lib/CodeGen/BackendUtil.cpp > cfe/trunk/lib/CodeGen/CGCall.cpp > cfe/trunk/lib/CodeGen/CGVTables.cpp > cfe/trunk/lib/CodeGen/CodeGenModule.cpp > cfe/trunk/lib/CodeGen/CodeGenModule.h > cfe/trunk/lib/Driver/Tools.cpp > cfe/trunk/lib/Frontend/CodeGenOptions.cpp > cfe/trunk/lib/Frontend/CompilerInvocation.cpp > cfe/trunk/test/CodeGen/2007-04-14-FNoBuiltin.c > cfe/trunk/test/CodeGen/libcalls-complex.c > cfe/trunk/test/CodeGen/libcalls-fno-builtin.c > cfe/trunk/test/CodeGen/nobuiltin.c > cfe/trunk/test/Sema/implicit-builtin-freestanding.c > > > Modified: cfe/trunk/lib/CodeGen/BackendUtil.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/BackendUtil.cpp?rev=256937&r1=256936&r2=256937&view=diff > ============================================================================== > --- cfe/trunk/lib/CodeGen/BackendUtil.cpp (original) > +++ cfe/trunk/lib/CodeGen/BackendUtil.cpp Wed Jan 6 08:35:46 2016 > @@ -249,6 +249,13 @@ static TargetLibraryInfoImpl *createTLII > TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple); > if (!CodeGenOpts.SimplifyLibCalls) > TLII->disableAllFunctions(); > + else { > + // Disable individual libc/libm calls in TargetLibraryInfo. > + LibFunc::Func F; > + for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs()) > + if (TLII->getLibFunc(FuncName, F)) > + TLII->setUnavailable(F); I noticed a difference in LTO with -fno-builtin-FOO, since this code has no way of running at LTO-time. Chad wondered if we might be, more generally, conflating the meanings of -ffreestanding and -fno-builtin. -fno-builtin-FOO doesn't necessarily block optimizations to a builtin function, it just designates a particular function as not being a builtin. I suggest we revert this part of the patch. There's also a follow-up question: should we stop deleting functions from TLI for (plain) -fno-builtin? > + } > > switch (CodeGenOpts.getVecLib()) { > case CodeGenOptions::Accelerate: _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
