diff options
Diffstat (limited to 'include/llvm/Target')
| -rw-r--r-- | include/llvm/Target/TargetRegisterInfo.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/llvm/Target/TargetRegisterInfo.h b/include/llvm/Target/TargetRegisterInfo.h index 36ac5df..711129f 100644 --- a/include/llvm/Target/TargetRegisterInfo.h +++ b/include/llvm/Target/TargetRegisterInfo.h @@ -376,7 +376,10 @@ public: /// /// Bits are numbered from the LSB, so the bit for physical register Reg can /// be found as (Mask[Reg / 32] >> Reg % 32) & 1. - /// NULL pointer is equivalent to an all-zero mask. + /// + /// A NULL pointer means that no register mask will be used, and call + /// instructions should use implicit-def operands to indicate call clobbered + /// registers. /// virtual const uint32_t *getCallPreservedMask(CallingConv::ID) const { // The default mask clobbers everything. All targets should override. |