[OpenCL][AMDGPU] Add support for -cl-denorms-are-zero

Adjust target features for amdgcn target when -cl-denorms-are-zero is set.

Denormal support is controlled by feature strings fp32-denormals fp64-denormals in amdgcn target. If -cl-denorms-are-zero is not set and the command line does not set fp32/64-denormals feature string, +fp32-denormals +fp64-denormals will be on for GPU's supporting them.

A new virtual function virtual void TargetInfo::adjustTargetOptions(const CodeGenOptions &CGOpts, TargetOptions &TargetOpts) const is introduced to allow adjusting target option by codegen option.

Differential Revision: https://reviews.llvm.org/D22815

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@278151 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 6 insertions, 0 deletions

diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index 958c28ecfe..a9378f83af 100644
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -40,6 +40,7 @@ struct fltSemantics;
 namespace clang {
 class DiagnosticsEngine;
 class LangOptions;
+class CodeGenOptions;
 class MacroBuilder;
 class SourceLocation;
 class SourceManager;
@@ -797,6 +798,10 @@ public:
   /// language options which change the target configuration.
   virtual void adjust(const LangOptions &Opts);
 
+  /// \brief Adjust target options based on codegen options.
+  virtual void adjustTargetOptions(const CodeGenOptions &CGOpts,
+                                   TargetOptions &TargetOpts) const {}
+
   /// \brief Initialize the map with the default set of target features for the
   /// CPU this should include all legal feature strings on the target.
   ///
diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index 5895bebc9c..8e8ca38b9e 100644
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -110,6 +110,7 @@ CODEGENOPT(ReciprocalMath    , 1, 0) ///< Allow FP divisions to be reassociated.
 CODEGENOPT(NoInline          , 1, 0) ///< Set when -fno-inline is enabled.
                                      ///< Disables use of the inline keyword.
 CODEGENOPT(NoNaNsFPMath      , 1, 0) ///< Assume FP arguments, results not NaN.
+CODEGENOPT(FlushDenorm       , 1, 0) ///< Allow FP denorm numbers to be flushed to zero
 CODEGENOPT(NoZeroInitializedInBSS , 1, 0) ///< -fno-zero-initialized-in-bss.
 /// \brief Method of Objective-C dispatch to use.
 ENUM_CODEGENOPT(ObjCDispatchMethod, ObjCDispatchMethodKind, 2, Legacy)