Add support for clang-cl's option -fexcess-precision.

This option is useful for clang and clang-cl.

Differential Revision: https://reviews.llvm.org/D141929

Author: zahiraam

clang/include/clang/Driver/Options.td

@@ -1579,6 +1579,7 @@ def fignore_exceptions : Flag<["-"], "fignore-exceptions">, Group<f_Group>, Flag
   HelpText<"Enable support for ignoring exception handling constructs">,
   MarshallingInfoFlag<LangOpts<"IgnoreExceptions">>;
 def fexcess_precision_EQ : Joined<["-"], "fexcess-precision=">, Group<f_Group>,
+  Flags<[CoreOption]>,
   HelpText<"Allows control over excess precision on targets where native "
   "support for the precision types is not available. By default, excess "
   "precision is used to calculate intermediate results following the "

clang/test/Driver/fexcess-precision.c

@@ -1,29 +1,62 @@
 // RUN: %clang -### -target i386 -fexcess-precision=fast -c %s 2>&1  \
 // RUN:   | FileCheck --check-prefix=CHECK-FAST %s
+// RUN: %clang_cl -### -target i386 -fexcess-precision=fast -c %s 2>&1  \
+// RUN:   | FileCheck --check-prefix=CHECK-FAST %s
+
 // RUN: %clang -### -target i386 -fexcess-precision=standard -c %s 2>&1  \
 // RUN:   | FileCheck --check-prefix=CHECK-STD %s
+// RUN: %clang_cl -### -target i386 -fexcess-precision=standard -c %s 2>&1  \
+// RUN:   | FileCheck --check-prefix=CHECK-STD %s
+
 // RUN: %clang -### -target i386 -fexcess-precision=16 -c %s 2>&1  \
 // RUN:   | FileCheck --check-prefix=CHECK-NONE %s
+// RUN: %clang_cl -### -target i386 -fexcess-precision=16 -c %s 2>&1  \
+// RUN:   | FileCheck --check-prefix=CHECK-NONE %s
+
 // RUN: %clang -### -target i386 -fexcess-precision=none -c %s 2>&1  \
 // RUN:   | FileCheck --check-prefix=CHECK-ERR-NONE %s
+// RUN: %clang_cl -### -target i386 -fexcess-precision=none -c %s 2>&1  \
+// RUN:   | FileCheck --check-prefix=CHECK-ERR-NONE %s
 
 // RUN: %clang -### -target x86_64 -fexcess-precision=fast -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-FAST %s
+// RUN: %clang_cl -### -target x86_64 -fexcess-precision=fast -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-FAST %s
+
 // RUN: %clang -### -target x86_64 -fexcess-precision=standard -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-STD %s
+// RUN: %clang_cl -### -target x86_64 -fexcess-precision=standard -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-STD %s
+
 // RUN: %clang -### -target x86_64 -fexcess-precision=16 -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-NONE %s
+// RUN: %clang_cl -### -target x86_64 -fexcess-precision=16 -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NONE %s
+
 // RUN: %clang -### -target x86_64 -fexcess-precision=none -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefixes=CHECK-ERR-NONE %s
+// RUN: %clang_cl -### -target x86_64 -fexcess-precision=none -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefixes=CHECK-ERR-NONE %s
 
 // RUN: %clang -### -target aarch64 -fexcess-precision=fast -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK %s
+// RUN: %clang_cl -### -target aarch64 -fexcess-precision=fast -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK %s
+
 // RUN: %clang -### -target aarch64 -fexcess-precision=standard -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK %s
+// RUN: %clang_cl -### -target aarch64 -fexcess-precision=standard -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK %s
+
 // RUN: %clang -### -target aarch64 -fexcess-precision=16 -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-ERR-16 %s
+// RUN: %clang_cl -### -target aarch64 -fexcess-precision=16 -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-ERR-16 %s
+
 // RUN: %clang -### -target aarch64 -fexcess-precision=none -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-ERR-NONE %s
+// RUN: %clang_cl -### -target aarch64 -fexcess-precision=none -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-ERR-NONE %s
 
 // CHECK-FAST: "-ffloat16-excess-precision=fast"
 // CHECK-STD: "-ffloat16-excess-precision=standard"