diff options
| author | Bob Wilson <bob.wilson@apple.com> | 2013-02-10 16:01:41 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2013-02-10 16:01:41 +0000 |
| commit | f0c5456d7d6a9f74281011297d86cb3b1fa53cc1 (patch) | |
| tree | f6e85b70a369b7303fae5ebf2e8f6a9b9e69de1c | |
| parent | 48559ba03a1bc47c8d7e6ad77615c48361132178 (diff) | |
Use -mno-implicit-float by default for kernel/kext code. <rdar://13177960>
Apple's kernel engineers have been expecting this behavior even though
we've never implemented it before, as far as I can tell. In recent months,
clang has gotten better at using vector instructions to optimize memcpy-like
operations, and that has exposed problems when vector/floating-point
instructions are used in kexts that don't support that. This behavior also
matches what Apple's GCC did for PowerPC targets.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174838 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Driver/Tools.cpp | 16 | ||||
| -rw-r--r-- | test/Driver/flags.c | 6 |
2 files changed, 18 insertions, 4 deletions
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp index c5499dea76..0ed010e4ea 100644 --- a/lib/Driver/Tools.cpp +++ b/lib/Driver/Tools.cpp @@ -1200,10 +1200,18 @@ void Clang::AddX86TargetArgs(const ArgList &Args, Args.hasArg(options::OPT_fapple_kext)) CmdArgs.push_back("-disable-red-zone"); - if (Args.hasFlag(options::OPT_msoft_float, - options::OPT_mno_soft_float, - false) || - Args.hasArg(options::OPT_mno_implicit_float)) + // Default to avoid implicit floating-point for kernel/kext code, but allow + // that to be overridden with -mno-soft-float. + bool NoImplicitFloat = (Args.hasArg(options::OPT_mkernel) || + Args.hasArg(options::OPT_fapple_kext)); + if (Arg *A = Args.getLastArg(options::OPT_msoft_float, + options::OPT_mno_soft_float, + options::OPT_mno_implicit_float)) { + const Option &O = A->getOption(); + NoImplicitFloat = (O.matches(options::OPT_mno_implicit_float) || + O.matches(options::OPT_msoft_float)); + } + if (NoImplicitFloat) CmdArgs.push_back("-no-implicit-float"); if (const char *CPUName = getX86TargetCPU(Args, getToolChain().getTriple())) { diff --git a/test/Driver/flags.c b/test/Driver/flags.c index d328b827bb..27862316f8 100644 --- a/test/Driver/flags.c +++ b/test/Driver/flags.c @@ -10,5 +10,11 @@ // RUN: %clang -target i386-apple-darwin9 -### -S -mno-implicit-float %s 2> %t.log // RUN: grep '"-no-implicit-float"' %t.log +// RUN: %clang -target i386-apple-darwin9 -### -S -mkernel %s 2> %t.log +// RUN: grep '"-no-implicit-float"' %t.log + +// RUN: %clang -target i386-apple-darwin9 -### -S -mkernel -mno-soft-float %s 2> %t.log +// RUN: grep '"-no-implicit-float"' %t.log | count 0 + // RUN: %clang -target armv7-apple-darwin10 -### -S -mno-implicit-float %s 2> %t.log // RUN: grep '"-no-implicit-float"' %t.log |