Move the segmented stack switch to a function attribute

This removes the -segmented-stacks command line flag in favor of a
per-function "split-stack" attribute.

Patch by Luqman Aden and Alex Crichton!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205997 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 4 insertions, 10 deletions

diff --git a/include/llvm/CodeGen/CommandFlags.h b/include/llvm/CodeGen/CommandFlags.h
index 02a4bb5537..0fe9e141b5 100644
--- a/include/llvm/CodeGen/CommandFlags.h
+++ b/include/llvm/CodeGen/CommandFlags.h
@@ -190,11 +190,6 @@ EnablePIE("enable-pie",
           cl::init(false));
 
 cl::opt<bool>
-SegmentedStacks("segmented-stacks",
-                cl::desc("Use segmented stacks if possible."),
-                cl::init(false));
-
-cl::opt<bool>
 UseInitArray("use-init-array",
              cl::desc("Use .init_array instead of .ctors."),
              cl::init(false));
@@ -229,7 +224,6 @@ static inline TargetOptions InitTargetOptionsFromCodeGenFlags() {
   Options.StackAlignmentOverride = OverrideStackAlignment;
   Options.TrapFuncName = TrapFuncName;
   Options.PositionIndependentExecutable = EnablePIE;
-  Options.EnableSegmentedStacks = SegmentedStacks;
   Options.UseInitArray = UseInitArray;
   return Options;
 }
diff --git a/include/llvm/CodeGen/MachineFunction.h b/include/llvm/CodeGen/MachineFunction.h
index 652d63dbbf..a55d436848 100644
--- a/include/llvm/CodeGen/MachineFunction.h
+++ b/include/llvm/CodeGen/MachineFunction.h
@@ -259,6 +259,9 @@ public:
     return MBBNumbering[N];
   }
 
+  /// Should we be emitting segmented stack stuff for the function
+  bool shouldSplitStack();
+
   /// getNumBlockIDs - Return the number of MBB ID's allocated.
   ///
   unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h
index 1f873439c6..122324fbb0 100644
--- a/include/llvm/Target/TargetOptions.h
+++ b/include/llvm/Target/TargetOptions.h
@@ -49,7 +49,7 @@ namespace llvm {
           JITEmitDebugInfoToDisk(false), GuaranteedTailCallOpt(false),
           DisableTailCalls(false), StackAlignmentOverride(0),
           EnableFastISel(false), PositionIndependentExecutable(false),
-          EnableSegmentedStacks(false), UseInitArray(false),
+          UseInitArray(false),
           DisableIntegratedAS(false), CompressDebugSections(false),
           TrapFuncName(""), FloatABIType(FloatABI::Default),
           AllowFPOpFusion(FPOpFusion::Standard) {}
@@ -152,8 +152,6 @@ namespace llvm {
     /// if the relocation model is anything other than PIC.
     unsigned PositionIndependentExecutable : 1;
 
-    unsigned EnableSegmentedStacks : 1;
-
     /// UseInitArray - Use .init_array instead of .ctors for static
     /// constructors.
     unsigned UseInitArray : 1;
@@ -217,7 +215,6 @@ inline bool operator==(const TargetOptions &LHS,
     ARE_EQUAL(StackAlignmentOverride) &&
     ARE_EQUAL(EnableFastISel) &&
     ARE_EQUAL(PositionIndependentExecutable) &&
-    ARE_EQUAL(EnableSegmentedStacks) &&
     ARE_EQUAL(UseInitArray) &&
     ARE_EQUAL(TrapFuncName) &&
     ARE_EQUAL(FloatABIType) &&