Add a target hook for FLT_EVAL_METHOD and use it to set the value on x86 with sse...

x87 math evaluates everything with 80 bits precision, so we have to set FLT_EVAL_METHOD
to "2".

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147311 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index 28059781791734e3b621b8730f5cabc9b5a51ebe..5e219262dd61e5f366ecb21664b9e27ff3a68c95 100644 (file)
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -256,6 +256,9 @@ public:
     return *LongDoubleFormat;
   }
 
+  /// getFloatEvalMethod - Return the value for the C99 FLT_EVAL_METHOD macro.
+  virtual unsigned getFloatEvalMethod() const { return 0; }
+
   // getLargeArrayMinWidth/Align - Return the minimum array size that is
   // 'large' and its alignment.
   unsigned getLargeArrayMinWidth() const { return LargeArrayMinWidth; }

diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 34258c10546cf37ca7110db7aa1c492992100b5b..bb1051d7403c0cec38696ac13de60d700e0b24b2 100644 (file)
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -1339,6 +1339,10 @@ public:
     BigEndian = false;
     LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;
   }
+  virtual unsigned getFloatEvalMethod() const {
+    // X87 evaluates with 80 bits "long double" precision.
+    return SSELevel == NoSSE ? 2 : 0;
+  }
   virtual void getTargetBuiltins(const Builtin::Info *&Records,
                                  unsigned &NumRecords) const {
     Records = BuiltinInfo;

diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index c67eba40b59ea694b065fe75787cb8b4c78144e6..f601f3d73ab619cdf678402145f5e91286286f8e 100644 (file)
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -513,7 +513,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   }
 
   // Macros to control C99 numerics and <float.h>
-  Builder.defineMacro("__FLT_EVAL_METHOD__", "0");
+  Builder.defineMacro("__FLT_EVAL_METHOD__", Twine(TI.getFloatEvalMethod()));
   Builder.defineMacro("__FLT_RADIX__", "2");
   int Dig = PickFP(&TI.getLongDoubleFormat(), -1/*FIXME*/, 17, 21, 33, 36);
   Builder.defineMacro("__DECIMAL_DIG__", Twine(Dig));

diff --git a/test/Preprocessor/init.c b/test/Preprocessor/init.c
index ec90d6a3bb5247820768e34be0d137707d4ca516..d890d4af9303543dfcf7246ab49dc57b50d5b96e 100644 (file)
--- a/test/Preprocessor/init.c
+++ b/test/Preprocessor/init.c
@@ -242,7 +242,7 @@
 // I386:#define __FLT_DENORM_MIN__ 1.40129846e-45F
 // I386:#define __FLT_DIG__ 6
 // I386:#define __FLT_EPSILON__ 1.19209290e-7F
-// I386:#define __FLT_EVAL_METHOD__ 0
+// I386:#define __FLT_EVAL_METHOD__ 2
 // I386:#define __FLT_HAS_DENORM__ 1
 // I386:#define __FLT_HAS_INFINITY__ 1
 // I386:#define __FLT_HAS_QUIET_NAN__ 1
@@ -315,7 +315,7 @@
 // I386:#define __i386__ 1
 // I386:#define i386 1
 //
-// RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-pc-linux-gnu < /dev/null | FileCheck -check-prefix I386-LINUX %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -check-prefix I386-LINUX %s
 //
 // I386-LINUX:#define __CHAR16_TYPE__ unsigned short
 // I386-LINUX:#define __CHAR32_TYPE__ unsigned int