[llvm] [ARM] Specifically delineate between different GPRCS2 positions (PR #116716)

[Oliver Stannard via llvm-commits]

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@@ -1211,11 +1217,18 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF,
       FPOffsetAfterPush = MFI.getObjectOffset(FramePtrSpillFI) +
                           ArgRegsSaveSize + FPCXTSaveSize + GPRCS1Size +
                           sizeOfSPAdjustment(*FPPushInst);
-      if (PushPopSplit == ARMSubtarget::SplitR11WindowsSEH)
-        FPOffsetAfterPush += DPRCSSize + DPRGapSize;
       LLVM_DEBUG(dbgs() << "Frame pointer in GPRCS2, offset "
                         << FPOffsetAfterPush << "  after that push\n");
       break;
+    case SpillArea::GPRCS3:
+      FPPushInst = GPRCS3Push;
+      FPOffsetAfterPush = MFI.getObjectOffset(FramePtrSpillFI) +
+                          ArgRegsSaveSize + FPCXTSaveSize + GPRCS1Size +
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ostannard wrote:

I think it would be better to include `GPRCS2Size` here for consistency, or at least assert that it is zero, so that this will be correct of we ever start using GPRCS2 and GPRCS3 together.

https://github.com/llvm/llvm-project/pull/116716