Implement -cl-single-precision-constant

llvm-svn: 120877
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index aa4eae0..88e3c8a 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -110,6 +110,9 @@
 
   unsigned SpellChecking : 1; // Whether to perform spell-checking for error
                               // recovery.
+  unsigned SinglePrecisionConstants : 1; // Whether to treat double-precision
+                                         // floating point constants as
+                                         // single precision constants.
   // FIXME: This is just a temporary option, for testing purposes.
   unsigned NoBitFieldTypeAlign : 1;
 
@@ -196,6 +199,7 @@
     DumpRecordLayouts = 0;
     DumpVTableLayouts = 0;
     SpellChecking = 1;
+    SinglePrecisionConstants = 0;
     NoBitFieldTypeAlign = 0;
   }
 
diff --git a/clang/include/clang/Driver/CC1Options.td b/clang/include/clang/Driver/CC1Options.td
index 27db9cf..eab473b 100644
--- a/clang/include/clang/Driver/CC1Options.td
+++ b/clang/include/clang/Driver/CC1Options.td
@@ -599,3 +599,5 @@
 
 def cl_opt_disable : Flag<"-cl-opt-disable">,
   HelpText<"OpenCL only. This option disables all optimizations. The default is optimizations are enabled.">;
+def cl_single_precision_constant : Flag<"-cl-single-precision-constant">,
+  HelpText<"OpenCL only. Treat double precision floating-point constant as single precision constant.">;
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 8795b38..7f9d4a5 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1418,6 +1418,7 @@
   Opts.DumpVTableLayouts = Args.hasArg(OPT_fdump_vtable_layouts);
   Opts.SpellChecking = !Args.hasArg(OPT_fno_spell_checking);
   Opts.NoBitFieldTypeAlign = Args.hasArg(OPT_fno_bitfield_type_align);
+  Opts.SinglePrecisionConstants = Args.hasArg(OPT_cl_single_precision_constant);
   Opts.OptimizeSize = 0;
 
   // FIXME: Eliminate this dependency.
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 270aa3e..177d61c 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2394,6 +2394,9 @@
     bool isExact = (result == APFloat::opOK);
     Res = FloatingLiteral::Create(Context, Val, isExact, Ty, Tok.getLocation());
 
+    if (getLangOptions().SinglePrecisionConstants && Ty == Context.DoubleTy)
+      ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast);
+
   } else if (!Literal.isIntegerLiteral()) {
     return ExprError();
   } else {
diff --git a/clang/test/CodeGen/cl-single-precision-constant.c b/clang/test/CodeGen/cl-single-precision-constant.c
new file mode 100644
index 0000000..adde193
--- /dev/null
+++ b/clang/test/CodeGen/cl-single-precision-constant.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 %s -x cl -cl-single-precision-constant -emit-llvm -o - | FileCheck %s
+
+float fn(float f) {
+  // CHECK: fmul float
+  // CHECK: fadd float
+  return f*2. + 1.;
+}