diff options
Diffstat (limited to 'include/llvm/CodeGen/MachineFrameInfo.h')
| -rw-r--r-- | include/llvm/CodeGen/MachineFrameInfo.h | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/include/llvm/CodeGen/MachineFrameInfo.h b/include/llvm/CodeGen/MachineFrameInfo.h index 05ab49961d..b5479ba09f 100644 --- a/include/llvm/CodeGen/MachineFrameInfo.h +++ b/include/llvm/CodeGen/MachineFrameInfo.h @@ -133,11 +133,14 @@ class MachineFrameInfo { uint64_t StackSize; /// OffsetAdjustment - The amount that a frame offset needs to be adjusted to - /// have the actual offset from the stack/frame pointer. The calculation is - /// MFI->getObjectOffset(Index) + StackSize - TFI.getOffsetOfLocalArea() + - /// OffsetAdjustment. If OffsetAdjustment is zero (default) then offsets are - /// away from TOS. If OffsetAdjustment == StackSize then offsets are toward - /// TOS. + /// have the actual offset from the stack/frame pointer. The exact usage of + /// this is target-dependent, but it is typically used to adjust between + /// SP-relative and FP-relative offsets. E.G., if objects are accessed via + /// SP then OffsetAdjustment is zero; if FP is used, OffsetAdjustment is set + /// to the distance between the initial SP and the value in FP. For many + /// targets, this value is only used when generating debug info (via + /// TargetRegisterInfo::getFrameIndexOffset); when generating code, the + /// corresponding adjustments are performed directly. int OffsetAdjustment; /// MaxAlignment - The prolog/epilog code inserter may process objects |