This adds new options -fdenormal-fp-math and passes through option -ffast-math

to CC1, which are translated to function attributes and can e.g. be mapped on
build attributes FP_exceptions and FP_denormal. Setting these build attributes
allows better selection of floating point libraries.

Differential Revision: https://reviews.llvm.org/D23840

llvm-svn: 280064

diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
index be7518b..d7e83e0 100644 (file)
--- a/clang/docs/UsersManual.rst
+++ b/clang/docs/UsersManual.rst
@@ -1075,6 +1075,15 @@ are listed below.
      ``Inf``, and
    * ``+0`` and ``-0`` are interchangeable.
 
+.. option:: -fdenormal-fp-math=[values]
+
+   Select which denormal numbers the code is permitted to require.
+
+   Valid values are: ``ieee``, ``preserve-sign``, and ``positive-zero``,
+   which correspond to IEEE 754 denormal numbers, the sign of a
+   flushed-to-zero number is preserved in the sign of 0, denormals are
+   flushed to positive zero, respectively.
+
 .. option:: -fwhole-program-vtables
 
    Enable whole-program vtable optimizations, such as single-implementation

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 98a23b2..eaf1d2a 100644 (file)
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -626,6 +626,7 @@ def : Flag<["-"], "fno-defer-pop">, Group<clang_ignored_gcc_optimization_f_Group
 def : Flag<["-"], "fextended-identifiers">, Group<clang_ignored_f_Group>;
 def : Flag<["-"], "fno-extended-identifiers">, Group<f_Group>, Flags<[Unsupported]>;
 def fhosted : Flag<["-"], "fhosted">, Group<f_Group>;
+def fdenormal_fp_math_EQ : Joined<["-"], "fdenormal-fp-math=">, Group<f_Group>, Flags<[CC1Option]>;
 def ffast_math : Flag<["-"], "ffast-math">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Allow aggressive, lossy floating-point optimizations">;
 def fno_fast_math : Flag<["-"], "fno-fast-math">, Group<f_Group>;
@@ -740,8 +741,8 @@ def fno_honor_infinities : Flag<["-"], "fno-honor-infinities">, Group<f_Group>;
 // This option was originally misspelt "infinites" [sic].
 def : Flag<["-"], "fhonor-infinites">, Alias<fhonor_infinities>;
 def : Flag<["-"], "fno-honor-infinites">, Alias<fno_honor_infinities>;
-def ftrapping_math : Flag<["-"], "ftrapping-math">, Group<f_Group>;
-def fno_trapping_math : Flag<["-"], "fno-trapping-math">, Group<f_Group>;
+def ftrapping_math : Flag<["-"], "ftrapping-math">, Group<f_Group>, Flags<[CC1Option]>;
+def fno_trapping_math : Flag<["-"], "fno-trapping-math">, Group<f_Group>, Flags<[CC1Option]>;
 def ffp_contract : Joined<["-"], "ffp-contract=">, Group<f_Group>,
   Flags<[CC1Option]>, HelpText<"Form fused FP ops (e.g. FMAs): fast (everywhere)"
   " | on (according to FP_CONTRACT pragma, default) | off (never fuse)">;

diff --git a/clang/include/clang/Frontend/CodeGenOptions.def b/clang/include/clang/Frontend/CodeGenOptions.def
index 187faea..23654b6 100644 (file)
--- a/clang/include/clang/Frontend/CodeGenOptions.def
+++ b/clang/include/clang/Frontend/CodeGenOptions.def
@@ -107,6 +107,7 @@ CODEGENOPT(NoImplicitFloat   , 1, 0) ///< Set when -mno-implicit-float is enable
 CODEGENOPT(NoInfsFPMath      , 1, 0) ///< Assume FP arguments, results not +-Inf.
 CODEGENOPT(NoSignedZeros     , 1, 0) ///< Allow ignoring the signedness of FP zero
 CODEGENOPT(ReciprocalMath    , 1, 0) ///< Allow FP divisions to be reassociated.
+CODEGENOPT(NoTrappingMath    , 1, 0) ///< Set when -fno-trapping-math is enabled.
 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.

diff --git a/clang/include/clang/Frontend/CodeGenOptions.h b/clang/include/clang/Frontend/CodeGenOptions.h
index 0bdc1ef..3ee0910 100644 (file)
--- a/clang/include/clang/Frontend/CodeGenOptions.h
+++ b/clang/include/clang/Frontend/CodeGenOptions.h
@@ -121,6 +121,9 @@ public:
   /// The ABI to use for passing floating point arguments.
   std::string FloatABI;
 
+  /// The floating-point denormal mode to use.
+  std::string FPDenormalMode;
+
   /// The float precision limit to use, if non-empty.
   std::string LimitFloatPrecision;
 

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 94261bf..f3eaef3 100644 (file)
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1722,6 +1722,13 @@ void CodeGenModule::ConstructAttributeList(
 
     FuncAttrs.addAttribute("less-precise-fpmad",
                            llvm::toStringRef(CodeGenOpts.LessPreciseFPMAD));
+
+    if (!CodeGenOpts.FPDenormalMode.empty())
+      FuncAttrs.addAttribute("denormal-fp-math",
+                             CodeGenOpts.FPDenormalMode);
+
+    FuncAttrs.addAttribute("no-trapping-math",
+                           llvm::toStringRef(CodeGenOpts.NoTrappingMath));
     FuncAttrs.addAttribute("no-infs-fp-math",
                            llvm::toStringRef(CodeGenOpts.NoInfsFPMath));
     FuncAttrs.addAttribute("no-nans-fp-math",

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index d17dc2e..da578dd 100644 (file)
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -4369,6 +4369,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (ReciprocalMath)
     CmdArgs.push_back("-freciprocal-math");
 
+  if (!TrappingMath) 
+    CmdArgs.push_back("-fno-trapping-math");
+
+  if (Args.hasArg(options::OPT_fdenormal_fp_math_EQ))
+    Args.AddLastArg(CmdArgs, options::OPT_fdenormal_fp_math_EQ);
+
   // Validate and pass through -fp-contract option.
   if (Arg *A = Args.getLastArg(options::OPT_ffast_math, FastMathAliasOption,
                                options::OPT_fno_fast_math,

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index e21f244..901a5a6 100644 (file)
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -576,6 +576,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.CorrectlyRoundedDivSqrt =
       Args.hasArg(OPT_cl_fp32_correctly_rounded_divide_sqrt);
   Opts.ReciprocalMath = Args.hasArg(OPT_freciprocal_math);
+  Opts.NoTrappingMath = Args.hasArg(OPT_fno_trapping_math);
   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);
@@ -794,6 +795,18 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
       Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val;
   }
 
+  if (Arg *A = Args.getLastArg(OPT_fdenormal_fp_math_EQ)) {
+    StringRef Val = A->getValue();
+    if (Val == "ieee")
+      Opts.FPDenormalMode = "ieee";
+    else if (Val == "preserve-sign")
+      Opts.FPDenormalMode = "preserve-sign";
+    else if (Val == "positive-zero")
+      Opts.FPDenormalMode = "positive-zero";
+    else
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Val;
+  }
+
   if (Arg *A = Args.getLastArg(OPT_fpcc_struct_return, OPT_freg_struct_return)) {
     if (A->getOption().matches(OPT_fpcc_struct_return)) {
       Opts.setStructReturnConvention(CodeGenOptions::SRCK_OnStack);

diff --git a/clang/test/CodeGen/denormalfpmode.c b/clang/test/CodeGen/denormalfpmode.c
new file mode 100644 (file)
index 0000000..b0013da
--- /dev/null
+++ b/clang/test/CodeGen/denormalfpmode.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -S -fdenormal-fp-math=ieee %s -emit-llvm -o - | FileCheck %s --check-prefix=CHECK-IEEE
+// RUN: %clang_cc1 -S -fdenormal-fp-math=preserve-sign %s -emit-llvm -o - | FileCheck %s --check-prefix=CHECK-PS
+// RUN: %clang_cc1 -S -fdenormal-fp-math=positive-zero %s -emit-llvm -o - | FileCheck %s --check-prefix=CHECK-PZ
+
+// CHECK-LABEL: main
+// CHECK-IEEE: attributes #0 = {{.*}}"denormal-fp-math"="ieee"{{.*}}
+// CHECK-PS: attributes #0 = {{.*}}"denormal-fp-math"="preserve-sign"{{.*}}
+// CHECK-PZ: attributes #0 = {{.*}}"denormal-fp-math"="positive-zero"{{.*}}
+
+int main() {
+  return 0;
+}

diff --git a/clang/test/CodeGen/noexceptionsfpmath.c b/clang/test/CodeGen/noexceptionsfpmath.c
new file mode 100644 (file)
index 0000000..a22e285
--- /dev/null
+++ b/clang/test/CodeGen/noexceptionsfpmath.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -S -fno-trapping-math %s -emit-llvm -o - | FileCheck %s
+
+// CHECK-LABEL: main
+// CHECK: attributes #0 = {{.*}}"no-trapping-math"="true"{{.*}}
+
+int main() {
+  return 0;
+}

diff --git a/clang/test/Driver/fast-math.c b/clang/test/Driver/fast-math.c
index 24c3038..c31f376 100644 (file)
--- a/clang/test/Driver/fast-math.c
+++ b/clang/test/Driver/fast-math.c
@@ -231,3 +231,20 @@
 // CHECK-NO-UNSAFE-MATH: "-cc1"
 // CHECK-NO-UNSAFE-MATH-NOT: "-menable-unsafe-fp-math"
 // CHECK-NO-UNSAFE-MATH: "-o"
+//
+// RUN: %clang -### -fexceptions-fp-math -fno-exceptions-fp-math -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NO-FP-EXCEPTIONS %s
+// RUN: %clang -### -fno-exceptions-fp-math -fexceptions-fp-math -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-FP-EXCEPTIONS %s
+// CHECK-NO-FP-EXCEPTIONS: "-fno-exceptions-fp-math"
+// CHECK-FP-EXCEPTIONS-NOT: "-fno-exceptions-fp-math"
+//
+// RUN: %clang -### -fdenormal-fp-math=ieee -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-FP-DENORMAL-IEEE %s
+// RUN: %clang -### -fdenormal-fp-math=preserve-sign -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-FP-DENORMAL-PS %s
+// RUN: %clang -### -fdenormal-fp-math=positive-zero -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-FP-DENORMAL-PZ %s
+// CHECK-FP-DENORMAL-IEEE: "-fdenormal-fp-math=ieee"
+// CHECK-FP-DENORMAL-PS: "-fdenormal-fp-math=preserve-sign"
+// CHECK-FP-DENORMAL-PZ: "-fdenormal-fp-math=positive-zero"