FreeBSD: enable __float128 on x86 and powerpc64le

[brooks]

Summary

This is a prerequisite for proper runtime support on FreeBSD as it will
allow such a runtime to be compiled.

[dim]

LGTM

[arichardson]

Could you add a RUN: line to `clang/test/CodeGenCXX/float128-declarations.cpp? Code LGTM.

// RUN: %clang_cc1 -no-opaque-pointers -emit-llvm -triple x86_64-unknown-freebsd -std=c++11 \
// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86

[emaste]

OK. I think the switch will become unwieldy if additional arch-dependent things are added but could be dealt with then.

[brooks]

Add a test as requested by @arichardson

[arichardson]

@brooks do you want me to commit this for you or do you have commit access?

[brooks]

@arichardson please commit. I do not have commit access. Thanks

[pkubaj]

Could you modify it appropriately to also enable ppc, ppc64 and ppc64le? I checked whether it works on FreeBSD 13.1-RELEASE and it builds and works fine.

EDIT: or better just go for now with ppc64le, since enabling for older variants should probably be done depending on the hardware.

[brooks]

• Rebase
• Add powerpc64le

[dim]

LGTM again :)

[nemanjai]

My comments are minor nits that don't require another review, so LGTM.

clang/lib/Basic/Targets/OSTargets.h

243–249

Seems a bit odd to have a separate switch on the same value for __float128 rather than using fallthrough.

clang/test/CodeGenCXX/float128-declarations.cpp

5–6 ↗

(On Diff #509934)

Now that you added ppc64le, did you mean to also add a line with that triple without the explicit -target-feature?

[emaste]

Looks like this still needs someone to push it -- @brooks if you rebase and send to GitHub I cna pick it up

[brad]

You can close this.

[arichardson]

In D135171#4657080, @brad wrote:

You can close this.

The submitted patch https://github.com/llvm/llvm-project/commit/23c47eba879769a29772c999be2991201c2fe399 was not the same since it omitted ppc64. So I guess this should remain open

clang/lib/Basic/Targets/OSTargets.h

void getOSDefines(const LangOptions &Opts, const llvm::Triple &Triple,
     // not necessarily a superset of ASCII.
     //
     // FIXME: This is wrong; the macro refers to the numerical values
     // of wchar_t *literals*, which are not locale-dependent. However,
     // FreeBSD systems apparently depend on us getting this wrong, and
     // setting this to 1 is conforming even if all the basic source
     // character literals have the same encoding as char and wchar_t.
     Builder.defineMacro("__STDC_MB_MIGHT_NEQ_WC__", "1");
+
+    if (this->HasFloat128)
+      Builder.defineMacro("__FLOAT128__");
   }
 
 public:
   FreeBSDTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : OSTargetInfo<Target>(Triple, Opts) {
     switch (Triple.getArch()) {
-    default:
     case llvm::Triple::x86:
     case llvm::Triple::x86_64:
+      this->HasFloat128 = true;
+      [[fallthrough]];
+    default:
       this->MCountName = ".mcount";
       break;
     case llvm::Triple::mips:
     case llvm::Triple::mipsel:
     case llvm::Triple::ppc:
     case llvm::Triple::ppcle:
     case llvm::Triple::ppc64:
     case llvm::Triple::ppc64le:
       this->MCountName = "_mcount";