Migrate existing backends that care about software floating point

to use the information in the module rather than TargetOptions.

We've had and clang has used the use-soft-float attribute for some
time now so have the backends set a subtarget feature based on
a particular function now that subtargets are created based on
functions and function attributes.

For the one middle end soft float check go ahead and create
an overloadable TargetLowering::useSoftFloat function that
just checks the TargetSubtargetInfo in all cases.

Also remove the command line option that hard codes whether or
not soft-float is set by using the attribute for all of the
target specific test cases - for the generic just go ahead and
add the attribute in the one case that showed up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237079 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetLowering.h

@@ -165,6 +165,7 @@ public:
 
   bool isBigEndian() const { return !IsLittleEndian; }
   bool isLittleEndian() const { return IsLittleEndian; }
+  virtual bool useSoftFloat() const { return false; }
 
   /// Return the pointer type for the given address space, defaults to
   /// the pointer type from the data layout.

include/llvm/Target/TargetOptions.h

@@ -63,7 +63,7 @@ namespace llvm {
         : PrintMachineCode(false), NoFramePointerElim(false),
           LessPreciseFPMADOption(false), UnsafeFPMath(false),
           NoInfsFPMath(false), NoNaNsFPMath(false),
-          HonorSignDependentRoundingFPMathOption(false), UseSoftFloat(false),
+          HonorSignDependentRoundingFPMathOption(false),
           NoZerosInBSS(false),
           GuaranteedTailCallOpt(false),
           DisableTailCalls(false), StackAlignmentOverride(0),
@@ -127,12 +127,6 @@ namespace llvm {
     unsigned HonorSignDependentRoundingFPMathOption : 1;
     bool HonorSignDependentRoundingFPMath() const;
 
-    /// UseSoftFloat - This flag is enabled when the -soft-float flag is
-    /// specified on the command line.  When this flag is on, the code generator
-    /// will generate libcalls to the software floating point library instead of
-    /// target FP instructions.
-    unsigned UseSoftFloat : 1;
-
     /// NoZerosInBSS - By default some codegens place zero-initialized data to
     /// .bss section. This flag disables such behaviour (necessary, e.g. for
     /// crt*.o compiling).
@@ -240,7 +234,6 @@ inline bool operator==(const TargetOptions &LHS,
     ARE_EQUAL(NoInfsFPMath) &&
     ARE_EQUAL(NoNaNsFPMath) &&
     ARE_EQUAL(HonorSignDependentRoundingFPMathOption) &&
-    ARE_EQUAL(UseSoftFloat) &&
     ARE_EQUAL(NoZerosInBSS) &&
     ARE_EQUAL(GuaranteedTailCallOpt) &&
     ARE_EQUAL(DisableTailCalls) &&