[Driver] Enable __float128 support on X86 on FreeBSD / NetBSD (#72788)

(cherry picked from commit 23c47eb)

Author: brad0

clang/lib/Basic/Targets/OSTargets.h

@@ -217,6 +217,8 @@ class LLVM_LIBRARY_VISIBILITY FreeBSDTargetInfo : public OSTargetInfo<Target> {
     Builder.defineMacro("__FreeBSD_cc_version", Twine(CCVersion));
     Builder.defineMacro("__KPRINTF_ATTRIBUTE__");
     DefineStd(Builder, "unix", Opts);
+    if (this->HasFloat128)
+      Builder.defineMacro("__FLOAT128__");
 
     // On FreeBSD, wchar_t contains the number of the code point as
     // used by the character set of the locale. These character sets are
@@ -234,9 +236,11 @@ class LLVM_LIBRARY_VISIBILITY FreeBSDTargetInfo : public OSTargetInfo<Target> {
   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:
@@ -425,12 +429,22 @@ class LLVM_LIBRARY_VISIBILITY NetBSDTargetInfo : public OSTargetInfo<Target> {
     Builder.defineMacro("__unix__");
     if (Opts.POSIXThreads)
       Builder.defineMacro("_REENTRANT");
+    if (this->HasFloat128)
+      Builder.defineMacro("__FLOAT128__");
   }
 
 public:
   NetBSDTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : OSTargetInfo<Target>(Triple, Opts) {
     this->MCountName = "__mcount";
+    switch (Triple.getArch()) {
+    default:
+      break;
+    case llvm::Triple::x86:
+    case llvm::Triple::x86_64:
+      this->HasFloat128 = true;
+      break;
+    }
   }
 };
 

clang/test/CodeGenCXX/float128-declarations.cpp

@@ -6,9 +6,17 @@
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
 // RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown-linux-gnu -std=c++11 \
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
-// RUN: %clang_cc1 -emit-llvm -triple i686-pc-openbsd -std=c++11 \
+// RUN: %clang_cc1 -emit-llvm -triple i386-unknown-freebsd -std=c++11 \
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
-// RUN: %clang_cc1 -emit-llvm -triple amd64-pc-openbsd -std=c++11 \
+// RUN: %clang_cc1 -emit-llvm -triple amd64-unknown-freebsd -std=c++11 \
+// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
+// RUN: %clang_cc1 -emit-llvm -triple i386-unknown-netbsd -std=c++11 \
+// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
+// RUN: %clang_cc1 -emit-llvm -triple amd64-unknown-netbsd -std=c++11 \
+// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
+// RUN: %clang_cc1 -emit-llvm -triple i386-unknown-openbsd -std=c++11 \
+// RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
+// RUN: %clang_cc1 -emit-llvm -triple amd64-unknown-openbsd -std=c++11 \
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86
 // RUN: %clang_cc1 -emit-llvm -triple i386-pc-solaris2.11 -std=c++11 \
 // RUN:   %s -o - | FileCheck %s -check-prefix=CHECK-X86