Add skipFunction() check to MachineFunctionSplitter pass

Author: grigorypas

llvm/lib/CodeGen/MachineFunctionSplitter.cpp

@@ -136,7 +136,7 @@ bool MachineFunctionSplitter::runOnMachineFunction(MachineFunction &MF) {
   // of exception handling code may be split to cold if user passes the
   // mfs-split-ehcode flag.
   bool UseProfileData = MF.getFunction().hasProfileData();
-  if (!UseProfileData && !SplitAllEHCode)
+  if (!skipFunction(MF.getFunction()) && !UseProfileData && !SplitAllEHCode)
     return false;
 
   const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();

llvm/test/CodeGen/Generic/machine-function-splitter-optnone.ll

@@ -0,0 +1,50 @@
+; REQUIRES: x86-registered-target
+
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions | FileCheck %s
+
+;; Check that functions with optnone attribute are not split.
+; CHECK-LABEL: foo_optnone:
+; CHECK-NOT:   .section .text.split.foo_optnone
+; CHECK-NOT:   foo_optnone.cold:
+; CHECK:       .LBB0_2:
+; CHECK:       .size   foo_optnone
+
+define void @foo_optnone(i1 zeroext %0) nounwind optnone noinline !prof !14 !section_prefix !15 {
+entry:
+  br i1 %0, label %hot, label %cold, !prof !17
+
+hot:
+  %1 = call i32 @bar()
+  br label %exit
+
+cold:
+  %2 = call i32 @baz()
+  br label %exit
+
+exit:
+  %3 = tail call i32 @qux()
+  ret void
+}
+
+declare i32 @bar()
+declare i32 @baz()
+declare i32 @qux()
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 1, !"ProfileSummary", !1}
+!1 = !{!2, !3, !4, !5, !6, !7, !8, !9}
+!2 = !{!"ProfileFormat", !"InstrProf"}
+!3 = !{!"TotalCount", i64 10000}
+!4 = !{!"MaxCount", i64 10}
+!5 = !{!"MaxInternalCount", i64 1}
+!6 = !{!"MaxFunctionCount", i64 1000}
+!7 = !{!"NumCounts", i64 3}
+!8 = !{!"NumFunctions", i64 5}
+!9 = !{!"DetailedSummary", !10}
+!10 = !{!11, !12, !13}
+!11 = !{i32 10000, i64 100, i32 1}
+!12 = !{i32 999900, i64 100, i32 1}
+!13 = !{i32 999999, i64 1, i32 2}
+!14 = !{!"function_entry_count", i64 7000}
+!15 = !{!"function_section_prefix", !"hot"}
+!17 = !{!"branch_weights", i32 7000, i32 0}