[StackMaps] Allow the target to pre-process the live-out mask

Some targets, PowerPC for example, have pseudo-registers (such as that used to
represent the rounding mode), that don't have DWARF register numbers or a
register class. These are used only for internal dependency tracking, and
should not appear in the recorded live-outs. This adds a callback allowing the
target to pre-process the live-out mask in order to remove these kinds of
registers so that the StackMaps code does not complain about them and/or
attempt to include them in the output.

This will be used by the PowerPC target in a future commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225805 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Target/TargetRegisterInfo.h b/include/llvm/Target/TargetRegisterInfo.h
index d5c048e010ecdbaf9beb23a3e226e43f50730932..a7552565c9385186fbb6512e0e114f133ad0211d 100644 (file)
--- a/include/llvm/Target/TargetRegisterInfo.h
+++ b/include/llvm/Target/TargetRegisterInfo.h
@@ -456,6 +456,11 @@ public:
   /// used by register scavenger to determine what registers are free.
   virtual BitVector getReservedRegs(const MachineFunction &MF) const = 0;
 
+  /// Prior to adding the live-out mask to a stackmap or patchpoint
+  /// instruction, provide the target the opportunity to adjust it (mainly to
+  /// remove pseudo-registers that should be ignored).
+  virtual void adjustStackMapLiveOutMask(uint32_t *Mask) const { }
+
   /// getMatchingSuperReg - Return a super-register of the specified register
   /// Reg so its sub-register of index SubIdx is Reg.
   unsigned getMatchingSuperReg(unsigned Reg, unsigned SubIdx,

diff --git a/lib/CodeGen/StackMapLivenessAnalysis.cpp b/lib/CodeGen/StackMapLivenessAnalysis.cpp
index c2ee87a3de8f16e4143f2206a446a83ff82a8ae6..767f43a420fd932e0ea6f5cd85d84906a67fc220 100644 (file)
--- a/lib/CodeGen/StackMapLivenessAnalysis.cpp
+++ b/lib/CodeGen/StackMapLivenessAnalysis.cpp
@@ -123,5 +123,7 @@ uint32_t *StackMapLiveness::createRegisterMask() const {
   for (LivePhysRegs::const_iterator RI = LiveRegs.begin(), RE = LiveRegs.end();
        RI != RE; ++RI)
     Mask[*RI / 32] |= 1U << (*RI % 32);
+
+  TRI->adjustStackMapLiveOutMask(Mask);
   return Mask;
 }