Fix dynamic linking on PPC64.
Dynamic linking on PPC64 has had problems since we had to move the top-down
hazard-detection logic post-ra. For dynamic linking to work there needs to be
a nop placed after every call. It turns out that it is really hard to guarantee
that nothing will be placed in between the call (bl) and the nop during post-ra
scheduling. Previous attempts at fixing this by placing logic inside the
hazard detector only partially worked.
This is now fixed in a different way: call+nop codegen-only instructions. As far
as CodeGen is concerned the pair is now a single instruction and cannot be split.
This solution works much better than previous attempts.
The scoreboard hazard detector is also renamed to be more generic, there is currently
no cpu-specific logic in it.
llvm-svn: 153816
diff --git a/llvm/lib/Target/PowerPC/PPCHazardRecognizers.h b/llvm/lib/Target/PowerPC/PPCHazardRecognizers.h
index d80a385..55b45d0 100644
--- a/llvm/lib/Target/PowerPC/PPCHazardRecognizers.h
+++ b/llvm/lib/Target/PowerPC/PPCHazardRecognizers.h
@@ -21,16 +21,19 @@
namespace llvm {
-/// PPCHazardRecognizer440 - This class implements a scoreboard-based
-/// hazard recognizer for the PPC 440 and friends.
-class PPCHazardRecognizer440 : public ScoreboardHazardRecognizer {
+/// PPCScoreboardHazardRecognizer - This class implements a scoreboard-based
+/// hazard recognizer for generic PPC processors.
+class PPCScoreboardHazardRecognizer : public ScoreboardHazardRecognizer {
const ScheduleDAG *DAG;
public:
- PPCHazardRecognizer440(const InstrItineraryData *ItinData,
+ PPCScoreboardHazardRecognizer(const InstrItineraryData *ItinData,
const ScheduleDAG *DAG_) :
ScoreboardHazardRecognizer(ItinData, DAG_), DAG(DAG_) {}
+ virtual HazardType getHazardType(SUnit *SU, int Stalls);
virtual void EmitInstruction(SUnit *SU);
+ virtual void AdvanceCycle();
+ virtual void Reset();
};
/// PPCHazardRecognizer970 - This class defines a finite state automata that
@@ -49,9 +52,6 @@
// HasCTRSet - If the CTR register is set in this group, disallow BCTRL.
bool HasCTRSet;
- // Was the last instruction issued a BL8_ELF
- bool LastWasBL8_ELF;
-
// StoredPtr - Keep track of the address of any store. If we see a load from
// the same address (or one that aliases it), disallow the store. We can have
// up to four stores in one dispatch group, hence we track up to 4.