[clang][patch][FPEnv] Make initialization of C++ globals strictfp aware

@kpn pointed out that the global variable initialization functions didn't
have the "strictfp" metadata set correctly, and @rjmccall said that there
was buggy code in SetFPModel and StartFunction, this patch is to solve
those problems. When Sema creates a FunctionDecl, it sets the
FunctionDeclBits.UsesFPIntrin to "true" if the lexical FP settings
(i.e. a combination of command line options and #pragma float_control
settings) correspond to ConstrainedFP mode. That bit is used when CodeGen
starts codegen for a llvm function, and it translates into the
"strictfp" function attribute. See bugs.llvm.org/show_bug.cgi?id=44571

Reviewed By: Aaron Ballman

Differential Revision: https://reviews.llvm.org/D102343

1 files changed, 8 insertions, 9 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ee997908..5ce5d12 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -6280,14 +6280,12 @@ static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context,
   QualType OverloadTy = Context.getFunctionType(FT->getReturnType(),
                                                 OverloadParams, EPI);
   DeclContext *Parent = FDecl->getParent();
-  FunctionDecl *OverloadDecl = FunctionDecl::Create(Context, Parent,
-                                                    FDecl->getLocation(),
-                                                    FDecl->getLocation(),
-                                                    FDecl->getIdentifier(),
-                                                    OverloadTy,
-                                                    /*TInfo=*/nullptr,
-                                                    SC_Extern, false,
-                                                    /*hasPrototype=*/true);
+  FunctionDecl *OverloadDecl = FunctionDecl::Create(
+      Context, Parent, FDecl->getLocation(), FDecl->getLocation(),
+      FDecl->getIdentifier(), OverloadTy,
+      /*TInfo=*/nullptr, SC_Extern, Sema->getCurFPFeatures().isFPConstrained(),
+      false,
+      /*hasPrototype=*/true);
   SmallVector<ParmVarDecl*, 16> Params;
   FT = cast<FunctionProtoType>(OverloadTy);
   for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
@@ -19529,7 +19527,8 @@ ExprResult RebuildUnknownAnyExpr::resolveDecl(Expr *E, ValueDecl *VD) {
         FunctionDecl *NewFD = FunctionDecl::Create(
             S.Context, FD->getDeclContext(), Loc, Loc,
             FD->getNameInfo().getName(), DestType, FD->getTypeSourceInfo(),
-            SC_None, false /*isInlineSpecified*/, FD->hasPrototype(),
+            SC_None, S.getCurFPFeatures().isFPConstrained(),
+            false /*isInlineSpecified*/, FD->hasPrototype(),
             /*ConstexprKind*/ ConstexprSpecKind::Unspecified);
 
         if (FD->getQualifier())