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.

llvm-svn: 237079

6 files changed, 28 insertions, 13 deletions

diff --git a/llvm/lib/Target/ARM/ARM.td b/llvm/lib/Target/ARM/ARM.td
index 9882227905c..c7ea18a17fe 100644
--- a/llvm/lib/Target/ARM/ARM.td
+++ b/llvm/lib/Target/ARM/ARM.td
@@ -23,6 +23,9 @@ include "llvm/Target/Target.td"
 def ModeThumb  : SubtargetFeature<"thumb-mode", "InThumbMode", "true",
                                   "Thumb mode">;
 
+def ModeSoftFloat : SubtargetFeature<"soft-float", "UseSoftFloat", "true",
+                                     "Use software floating point features.">;
+
 //===----------------------------------------------------------------------===//
 // ARM Subtarget features.
 //
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index a3743d452e0..fd956d4670e 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -170,7 +170,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   if (Subtarget->isTargetMachO()) {
     // Uses VFP for Thumb libfuncs if available.
     if (Subtarget->isThumb() && Subtarget->hasVFP2() &&
-        Subtarget->hasARMOps() && !TM.Options.UseSoftFloat) {
+        Subtarget->hasARMOps() && !Subtarget->useSoftFloat()) {
       // Single-precision floating-point arithmetic.
       setLibcallName(RTLIB::ADD_F32, "__addsf3vfp");
       setLibcallName(RTLIB::SUB_F32, "__subsf3vfp");
@@ -401,7 +401,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
     addRegisterClass(MVT::i32, &ARM::tGPRRegClass);
   else
     addRegisterClass(MVT::i32, &ARM::GPRRegClass);
-  if (!TM.Options.UseSoftFloat && Subtarget->hasVFP2() &&
+  if (!Subtarget->useSoftFloat() && Subtarget->hasVFP2() &&
       !Subtarget->isThumb1Only()) {
     addRegisterClass(MVT::f32, &ARM::SPRRegClass);
     addRegisterClass(MVT::f64, &ARM::DPRRegClass);
@@ -820,7 +820,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   }
   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
 
-  if (!TM.Options.UseSoftFloat && Subtarget->hasVFP2() &&
+  if (!Subtarget->useSoftFloat() && Subtarget->hasVFP2() &&
       !Subtarget->isThumb1Only()) {
     // Turn f64->i64 into VMOVRRD, i64 -> f64 to VMOVDRR
     // iff target supports vfp2.
@@ -861,7 +861,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   setOperationAction(ISD::FSINCOS,   MVT::f32, Expand);
   setOperationAction(ISD::FREM,      MVT::f64, Expand);
   setOperationAction(ISD::FREM,      MVT::f32, Expand);
-  if (!TM.Options.UseSoftFloat && Subtarget->hasVFP2() &&
+  if (!Subtarget->useSoftFloat() && Subtarget->hasVFP2() &&
       !Subtarget->isThumb1Only()) {
     setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
     setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
@@ -875,7 +875,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   }
 
   // Various VFP goodness
-  if (!TM.Options.UseSoftFloat && !Subtarget->isThumb1Only()) {
+  if (!Subtarget->useSoftFloat() && !Subtarget->isThumb1Only()) {
     // FP-ARMv8 adds f64 <-> f16 conversion. Before that it should be expanded.
     if (!Subtarget->hasFPARMv8() || Subtarget->isFPOnlySP()) {
       setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
@@ -932,7 +932,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
 
   setStackPointerRegisterToSaveRestore(ARM::SP);
 
-  if (TM.Options.UseSoftFloat || Subtarget->isThumb1Only() ||
+  if (Subtarget->useSoftFloat() || Subtarget->isThumb1Only() ||
       !Subtarget->hasVFP2())
     setSchedulingPreference(Sched::RegPressure);
   else
@@ -956,6 +956,10 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   setMinFunctionAlignment(Subtarget->isThumb() ? 1 : 2);
 }
 
+bool ARMTargetLowering::useSoftFloat() const {
+  return Subtarget->useSoftFloat();
+}
+
 // FIXME: It might make sense to define the representative register class as the
 // nearest super-register that has a non-null superset. For example, DPR_VFP2 is
 // a super-register of SPR, and DPR is a superset if DPR_VFP2. Consequently,
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.h b/llvm/lib/Target/ARM/ARMISelLowering.h
index 76b0d8851f5..63e87c5282d 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.h
+++ b/llvm/lib/Target/ARM/ARMISelLowering.h
@@ -231,6 +231,7 @@ namespace llvm {
                                const ARMSubtarget &STI);
 
     unsigned getJumpTableEncoding() const override;
+    bool useSoftFloat() const override;
 
     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
 
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.cpp b/llvm/lib/Target/ARM/ARMSubtarget.cpp
index 6e0a6df9280..89aab260366 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.cpp
+++ b/llvm/lib/Target/ARM/ARMSubtarget.cpp
@@ -145,6 +145,7 @@ void ARMSubtarget::initializeEnvironment() {
   HasVMLxForwarding = false;
   SlowFPBrcc = false;
   InThumbMode = false;
+  UseSoftFloat = false;
   HasThumb2 = false;
   NoARM = false;
   IsR9Reserved = ReserveR9;
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 0b8b7801f3d..ed1c6a0fc64 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -100,6 +100,9 @@ protected:
   /// InThumbMode - True if compiling for Thumb, false for ARM.
   bool InThumbMode;
 
+  /// UseSoftFloat - True if we're using software floating point features.
+  bool UseSoftFloat;
+
   /// HasThumb2 - True if Thumb2 instructions are supported.
   bool HasThumb2;
 
@@ -393,6 +396,7 @@ public:
   bool isAPCS_ABI() const;
   bool isAAPCS_ABI() const;
 
+  bool useSoftFloat() const { return UseSoftFloat; }
   bool isThumb() const { return InThumbMode; }
   bool isThumb1Only() const { return InThumbMode && !HasThumb2; }
   bool isThumb2() const { return InThumbMode && HasThumb2; }
diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.cpp b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
index ae333401915..bd29a052c37 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
@@ -207,13 +207,15 @@ ARMBaseTargetMachine::getSubtargetImpl(const Function &F) const {
   // function before we can generate a subtarget. We also need to use
   // it as a key for the subtarget since that can be the only difference
   // between two functions.
-  Attribute SFAttr = F.getFnAttribute("use-soft-float");
-  bool SoftFloat = !SFAttr.hasAttribute(Attribute::None)
-                       ? SFAttr.getValueAsString() == "true"
-                       : Options.UseSoftFloat;
-
-  auto &I = SubtargetMap[CPU + FS + (SoftFloat ? "use-soft-float=true"
-                                               : "use-soft-float=false")];
+  bool SoftFloat =
+      F.hasFnAttribute("use-soft-float") &&
+      F.getFnAttribute("use-soft-float").getValueAsString() == "true";
+  // If the soft float attribute is set on the function turn on the soft float
+  // subtarget feature.
+  if (SoftFloat)
+    FS += FS.empty() ? "+soft-float" : ",+soft-float";
+
+  auto &I = SubtargetMap[CPU + FS];
   if (!I) {
     // This needs to be done before we create a new subtarget since any
     // creation will depend on the TM and the code generation flags on the