[llvm] [llvm] Support save/restore point splitting in shrink-wrap (PR #119359)

[Matt Arsenault via llvm-commits]

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@@ -29,6 +29,33 @@ using namespace llvm;
 
 namespace {
 
+static int64_t calculateCSRSpillOffsets(MachineFrameInfo &MFI,
+                                        const TargetFrameLowering *TFI,
+                                        int MinCSFI, int FrameIdx) {
+  int LocalAreaOffset = -TFI->getOffsetOfLocalArea();
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arsenm wrote:

Why is this negated instead of using the raw value? Is this assuming the stack grows down? 

https://github.com/llvm/llvm-project/pull/119359