diff options
Diffstat (limited to 'llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp b/llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp index f0b7f587379..2b0ceaa6625 100644 --- a/llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp +++ b/llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp @@ -1051,10 +1051,26 @@ int HexagonFrameLowering::getFrameIndexReference(const MachineFunction &MF, bool HasExtraAlign = HRI.needsStackRealignment(MF); bool NoOpt = MF.getTarget().getOptLevel() == CodeGenOpt::None; + unsigned FrameSize = MFI.getStackSize(); unsigned SP = HRI.getStackRegister(), FP = HRI.getFrameRegister(); auto &HMFI = *MF.getInfo<HexagonMachineFunctionInfo>(); unsigned AP = HMFI.getStackAlignBasePhysReg(); - unsigned FrameSize = MFI.getStackSize(); + // It may happen that AP will be absent even HasAlloca && HasExtraAlign + // is true. HasExtraAlign may be set because of vector spills, without + // aligned locals or aligned outgoing function arguments. Since vector + // spills will ultimately be "unaligned", it is safe to use FP as the + // base register. + // In fact, in such a scenario the stack is actually not required to be + // aligned, although it may end up being aligned anyway, since this + // particular case is not easily detectable. The alignment will be + // unnecessary, but not incorrect. + // Unfortunately there is no quick way to verify that the above is + // indeed the case (and that it's not a result of an error), so just + // assume that missing AP will be replaced by FP. + // (A better fix would be to rematerialize AP from FP and always align + // vector spills.) + if (AP == 0) + AP = FP; bool UseFP = false, UseAP = false; // Default: use SP (except at -O0). // Use FP at -O0, except when there are objects with extra alignment. |
