Add the first backend support for on demand subtarget creation

based on the Function. This is currently used to implement
mips16 support in the mips backend via the existing module
pass resetting the subtarget.

Things to note:

a) This involved running resetTargetOptions before creating a
new subtarget so that code generation options like soft-float
could be recognized when creating the new subtarget. This is
to deal with initialization code in isel lowering that only
paid attention to the initial value.

b) Many of the existing testcases weren't using the soft-float
feature correctly. I've corrected these based on the check
values assuming that was the desired behavior.

c) The mips port now pays attention to the target-cpu and
target-features strings when generating code for a particular
function. I've removed these from one function where the
requested cpu and features didn't match the check lines in
the testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218492 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsTargetMachine.cpp b/lib/Target/Mips/MipsTargetMachine.cpp
index 79d1b4b..afa60d2 100644 (file)
--- a/lib/Target/Mips/MipsTargetMachine.cpp
+++ b/lib/Target/Mips/MipsTargetMachine.cpp
@@ -56,7 +56,8 @@ MipsTargetMachine::MipsTargetMachine(const Target &T, StringRef TT,
                                      Reloc::Model RM, CodeModel::Model CM,
                                      CodeGenOpt::Level OL, bool isLittle)
     : LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
-      Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, this),
+      isLittle(isLittle), Subtarget(nullptr),
+      DefaultSubtarget(TT, CPU, FS, isLittle, this),
       NoMips16Subtarget(TT, CPU, FS.empty() ? "-mips16" : FS.str() + ",-mips16",
                         isLittle, this),
       Mips16Subtarget(TT, CPU, FS.empty() ? "+mips16" : FS.str() + ",+mips16",
@@ -83,20 +84,47 @@ MipselTargetMachine(const Target &T, StringRef TT,
                     CodeGenOpt::Level OL)
   : MipsTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, true) {}
 
+const MipsSubtarget *
+MipsTargetMachine::getSubtargetImpl(const Function &F) const override {
+  AttributeSet FnAttrs = F.getAttributes();
+  Attribute CPUAttr =
+      FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-cpu");
+  Attribute FSAttr =
+      FnAttrs.getAttribute(AttributeSet::FunctionIndex, "target-features");
+
+  std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
+                        ? CPUAttr.getValueAsString().str()
+                        : TargetCPU;
+  std::string FS = !FSAttr.hasAttribute(Attribute::None)
+                       ? FSAttr.getValueAsString().str()
+                       : TargetFS;
+  bool hasMips16Attr =
+      !FnAttrs.getAttribute(AttributeSet::FunctionIndex, "mips16")
+           .hasAttribute(Attribute::None);
+  bool hasNoMips16Attr =
+      !FnAttrs.getAttribute(AttributeSet::FunctionIndex, "nomips16")
+           .hasAttribute(Attribute::None);
+
+  if (hasMips16Attr)
+    FS += FS.empty() ? "+mips16" : ",+mips16";
+  else if (hasNoMips16Attr)
+    FS += FS.empty() ? "-mips16" : ",-mips16";
+
+  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
+    // function that reside in TargetOptions.
+    resetTargetOptions(F);
+    I = make_unique<MipsSubtarget>(TargetTriple, CPU, FS, isLittle, this);
+  }
+  return I.get();
+}
+
 void MipsTargetMachine::resetSubtarget(MachineFunction *MF) {
   DEBUG(dbgs() << "resetSubtarget\n");
-  AttributeSet FnAttrs = MF->getFunction()->getAttributes();
-  bool Mips16Attr = FnAttrs.hasAttribute(AttributeSet::FunctionIndex, "mips16");
-  bool NoMips16Attr =
-      FnAttrs.hasAttribute(AttributeSet::FunctionIndex, "nomips16");
-  assert(!(Mips16Attr && NoMips16Attr) &&
-         "mips16 and nomips16 specified on the same function");
-  if (Mips16Attr)
-    Subtarget = &Mips16Subtarget;
-  else if (NoMips16Attr)
-    Subtarget = &NoMips16Subtarget;
-  else
-    Subtarget = &DefaultSubtarget;
+
+  Subtarget = const_cast<MipsSubtarget*>(getSubtargetImpl(MF->getFunction()));
   MF->setSubtarget(Subtarget);
   return;
 }

diff --git a/lib/Target/Mips/MipsTargetMachine.h b/lib/Target/Mips/MipsTargetMachine.h
index 58400cd..5ddbbcc 100644 (file)
--- a/lib/Target/Mips/MipsTargetMachine.h
+++ b/lib/Target/Mips/MipsTargetMachine.h
@@ -25,11 +25,14 @@ class formatted_raw_ostream;
 class MipsRegisterInfo;
 
 class MipsTargetMachine : public LLVMTargetMachine {
+  bool isLittle;
   MipsSubtarget *Subtarget;
   MipsSubtarget DefaultSubtarget;
   MipsSubtarget NoMips16Subtarget;
   MipsSubtarget Mips16Subtarget;
 
+  mutable StringMap<std::unique_ptr<MipsSubtarget>> SubtargetMap;
+
 public:
   MipsTargetMachine(const Target &T, StringRef TT, StringRef CPU, StringRef FS,
                     const TargetOptions &Options, Reloc::Model RM,
@@ -45,6 +48,8 @@ public:
     return &DefaultSubtarget;
   }
 
+  const MipsSubtarget *getSubtargetImpl(const Function &F) const override;
+
   /// \brief Reset the subtarget for the Mips target.
   void resetSubtarget(MachineFunction *MF);
 

diff --git a/test/CodeGen/Mips/fp16instrinsmc.ll b/test/CodeGen/Mips/fp16instrinsmc.ll
index 7ced36c..84d3814 100644 (file)
--- a/test/CodeGen/Mips/fp16instrinsmc.ll
+++ b/test/CodeGen/Mips/fp16instrinsmc.ll
@@ -385,7 +385,7 @@ entry:
 ; Function Attrs: nounwind
 declare double @exp2(double) #0
 
-attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="true" }
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
 attributes #1 = { nounwind readnone "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="true" }
 attributes #2 = { nounwind readnone }
 attributes #3 = { nounwind }

diff --git a/test/CodeGen/Mips/hfptrcall.ll b/test/CodeGen/Mips/hfptrcall.ll
index 9df8d90..683952d 100644 (file)
--- a/test/CodeGen/Mips/hfptrcall.ll
+++ b/test/CodeGen/Mips/hfptrcall.ll
@@ -118,8 +118,8 @@ entry:
 
 declare i32 @printf(i8*, ...) #1
 
-attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="true" }
-attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="true" }
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
 
 
 

diff --git a/test/CodeGen/Mips/nomips16.ll b/test/CodeGen/Mips/nomips16.ll
index 0affb16..5f7d74e 100644 (file)
--- a/test/CodeGen/Mips/nomips16.ll
+++ b/test/CodeGen/Mips/nomips16.ll
@@ -33,6 +33,6 @@ entry:
 ; CHECK:       .end    nofoo
 
 
-attributes #0 = { nounwind "less-precise-fpmad"="false" "mips16" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="true" }
-attributes #1 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "nomips16" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="true" }
+attributes #0 = { nounwind "less-precise-fpmad"="false" "mips16" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "nomips16" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
 

diff --git a/test/CodeGen/Mips/seleq.ll b/test/CodeGen/Mips/seleq.ll
index 190baad..9af422f 100644 (file)
--- a/test/CodeGen/Mips/seleq.ll
+++ b/test/CodeGen/Mips/seleq.ll
@@ -10,7 +10,7 @@
 @z3 = common global i32 0, align 4
 @z4 = common global i32 0, align 4
 
-define void @calc_seleq() nounwind "target-cpu"="mips32" "target-features"="+o32,+mips32" {
+define void @calc_seleq() nounwind {
 entry:
   %0 = load i32* @a, align 4
   %1 = load i32* @b, align 4