OpenCL C: Add support for a set of floating point

arithmetic relaxation flags:

-cl-no-signed-zeros
-cl-unsafe-math-optimizations
-cl-finite-math-only
-cl-fast-relaxed-math

Propagate the info to FP instruction flags as well
as function attributes where they are available.

llvm-svn: 223928

clang/include/clang/Driver/CC1Options.td

@@ -578,6 +578,8 @@ def cl_finite_math_only : Flag<["-"], "cl-finite-math-only">,
   HelpText<"OpenCL only. Allow floating-point optimizations that assume arguments and results are not NaNs or +-Inf.">;
 def cl_kernel_arg_info : Flag<["-"], "cl-kernel-arg-info">,
   HelpText<"OpenCL only. Generate kernel argument metadata.">;
+def cl_no_signed_zeros : Flag<["-"], "cl-no-signed-zeros">,
+  HelpText<"OpenCL only. Allow optimizations to ignore the signedness of the floating-point zero.">;
 def cl_unsafe_math_optimizations : Flag<["-"], "cl-unsafe-math-optimizations">,
   HelpText<"OpenCL only. Allow unsafe floating-point optimizations.  Also implies -cl-no-signed-zeros and -cl-mad-enable">;
 def cl_fast_relaxed_math : Flag<["-"], "cl-fast-relaxed-math">,

clang/include/clang/Frontend/CodeGenOptions.def

@@ -78,6 +78,7 @@ CODEGENOPT(EnableSegmentedStacks , 1, 0) ///< Set when -fsplit-stack is enabled.
 CODEGENOPT(NoGlobalMerge     , 1, 0) ///< Set when -mno-global-merge is enabled.
 CODEGENOPT(NoImplicitFloat   , 1, 0) ///< Set when -mno-implicit-float is enabled.
 CODEGENOPT(NoInfsFPMath      , 1, 0) ///< Assume FP arguments, results not +-Inf.
+CODEGENOPT(NoSignedZeros     , 1, 0) ///< Allow ignoring the signedness of FP zero
 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.

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -63,6 +63,12 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
     FMF.setNoNaNs();
     FMF.setNoInfs();
   }
+  if (CGM.getCodeGenOpts().NoNaNsFPMath) {
+    FMF.setNoNaNs();
+  }
+  if (CGM.getCodeGenOpts().NoSignedZeros) {
+    FMF.setNoSignedZeros();
+  }
   Builder.SetFastMathFlags(FMF);
 }
 

clang/lib/Frontend/CompilerInvocation.cpp

@@ -417,11 +417,13 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.LessPreciseFPMAD = Args.hasArg(OPT_cl_mad_enable);
   Opts.LimitFloatPrecision = Args.getLastArgValue(OPT_mlimit_float_precision);
   Opts.NoInfsFPMath = (Args.hasArg(OPT_menable_no_infinities) ||
-                       Args.hasArg(OPT_cl_finite_math_only)||
+                       Args.hasArg(OPT_cl_finite_math_only) ||
                        Args.hasArg(OPT_cl_fast_relaxed_math));
   Opts.NoNaNsFPMath = (Args.hasArg(OPT_menable_no_nans) ||
-                       Args.hasArg(OPT_cl_finite_math_only)||
+                       Args.hasArg(OPT_cl_unsafe_math_optimizations) ||
+                       Args.hasArg(OPT_cl_finite_math_only) ||
                        Args.hasArg(OPT_cl_fast_relaxed_math));
+  Opts.NoSignedZeros = Args.hasArg(OPT_cl_no_signed_zeros);
   Opts.NoZeroInitializedInBSS = Args.hasArg(OPT_mno_zero_initialized_in_bss);
   Opts.BackendOptions = Args.getAllArgValues(OPT_backend_option);
   Opts.NumRegisterParameters = getLastArgIntValue(Args, OPT_mregparm, 0, Diags);
@@ -1598,8 +1600,11 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   // inlining enabled.
   Opts.NoInlineDefine = !Opt || Args.hasArg(OPT_fno_inline);
 
-  Opts.FastMath = Args.hasArg(OPT_ffast_math);
-  Opts.FiniteMathOnly = Args.hasArg(OPT_ffinite_math_only);
+  Opts.FastMath = Args.hasArg(OPT_ffast_math) ||
+      Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.FiniteMathOnly = Args.hasArg(OPT_ffinite_math_only) ||
+      Args.hasArg(OPT_cl_finite_math_only) ||
+      Args.hasArg(OPT_cl_fast_relaxed_math);
 
   Opts.RetainCommentsFromSystemHeaders =
       Args.hasArg(OPT_fretain_comments_from_system_headers);

clang/test/CodeGenOpenCL/relaxed-fpmath.cl

@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s -check-prefix=NORMAL
+// RUN: %clang_cc1 %s -emit-llvm -cl-fast-relaxed-math -o - | FileCheck %s -check-prefix=FAST
+// RUN: %clang_cc1 %s -emit-llvm -cl-finite-math-only -o - | FileCheck %s -check-prefix=FINITE
+// RUN: %clang_cc1 %s -emit-llvm -cl-unsafe-math-optimizations -o - | FileCheck %s -check-prefix=UNSAFE
+// RUN: %clang_cc1 %s -emit-llvm -cl-no-signed-zeros -o - | FileCheck %s -check-prefix=NOSZ
+
+typedef __attribute__(( ext_vector_type(4) )) float float4;
+
+float spscalardiv(float a, float b) {
+  // CHECK: @spscalardiv(
+
+  // NORMAL: fdiv float    
+  // FAST: fdiv fast float
+  // FINITE: fdiv nnan ninf float
+  // UNSAFE: fdiv nnan float
+  // NOSZ: fdiv nsz float
+  return a / b;
+}
+// CHECK: attributes
+
+// NORMAL: "no-infs-fp-math"="false"
+// NORMAL: "no-nans-fp-math"="false"
+// NORMAL: "unsafe-fp-math"="false"
+
+// FAST: "no-infs-fp-math"="true"
+// FAST: "no-nans-fp-math"="true"
+// FAST: "unsafe-fp-math"="true"
+
+// FINITE: "no-infs-fp-math"="true"
+// FINITE: "no-nans-fp-math"="true"
+// FINITE: "unsafe-fp-math"="false"
+
+// UNSAFE: "no-infs-fp-math"="false"
+// UNSAFE: "no-nans-fp-math"="true"
+// UNSAFE: "unsafe-fp-math"="true"
+