[MachineFrameInfo] Refactoring around computeMaxcallFrameSize() (NFC) (#78001)

- Use computeMaxCallFrameSize() in PEI::calculateCallFrameInfo() instead of duplicating the code.

- Set AdjustsStack in FinalizeISel instead of in computeMaxCallFrameSize().

1 files changed, 12 insertions, 28 deletions

diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 8af17e6..e77d5e6 100644
--- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -228,9 +228,8 @@ bool PEI::runOnMachineFunction(MachineFunction &MF) {
   FrameIndexVirtualScavenging = TRI->requiresFrameIndexScavenging(MF);
   ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
 
-  // Calculate the MaxCallFrameSize and AdjustsStack variables for the
-  // function's frame information. Also eliminates call frame pseudo
-  // instructions.
+  // Calculate the MaxCallFrameSize value for the function's frame
+  // information. Also eliminates call frame pseudo instructions.
   calculateCallFrameInfo(MF);
 
   // Determine placement of CSR spill/restore code and prolog/epilog code:
@@ -350,17 +349,13 @@ bool PEI::runOnMachineFunction(MachineFunction &MF) {
   return true;
 }
 
-/// Calculate the MaxCallFrameSize and AdjustsStack
-/// variables for the function's frame information and eliminate call frame
-/// pseudo instructions.
+/// Calculate the MaxCallFrameSize variable for the function's frame
+/// information and eliminate call frame pseudo instructions.
 void PEI::calculateCallFrameInfo(MachineFunction &MF) {
   const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
   const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
   MachineFrameInfo &MFI = MF.getFrameInfo();
 
-  unsigned MaxCallFrameSize = 0;
-  bool AdjustsStack = MFI.adjustsStack();
-
   // Get the function call frame set-up and tear-down instruction opcode
   unsigned FrameSetupOpcode = TII.getCallFrameSetupOpcode();
   unsigned FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();
@@ -370,26 +365,15 @@ void PEI::calculateCallFrameInfo(MachineFunction &MF) {
   if (FrameSetupOpcode == ~0u && FrameDestroyOpcode == ~0u)
     return;
 
+  // (Re-)Compute the MaxCallFrameSize.
+  uint32_t MaxCFSIn =
+      MFI.isMaxCallFrameSizeComputed() ? MFI.getMaxCallFrameSize() : UINT32_MAX;
   std::vector<MachineBasicBlock::iterator> FrameSDOps;
-  for (MachineBasicBlock &BB : MF)
-    for (MachineBasicBlock::iterator I = BB.begin(); I != BB.end(); ++I)
-      if (TII.isFrameInstr(*I)) {
-        unsigned Size = TII.getFrameSize(*I);
-        if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
-        AdjustsStack = true;
-        FrameSDOps.push_back(I);
-      } else if (I->isInlineAsm()) {
-        // Some inline asm's need a stack frame, as indicated by operand 1.
-        unsigned ExtraInfo = I->getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
-        if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
-          AdjustsStack = true;
-      }
-
-  assert(!MFI.isMaxCallFrameSizeComputed() ||
-         (MFI.getMaxCallFrameSize() >= MaxCallFrameSize &&
-          !(AdjustsStack && !MFI.adjustsStack())));
-  MFI.setAdjustsStack(AdjustsStack);
-  MFI.setMaxCallFrameSize(MaxCallFrameSize);
+  MFI.computeMaxCallFrameSize(MF, &FrameSDOps);
+  assert(MFI.getMaxCallFrameSize() <= MaxCFSIn &&
+         "Recomputing MaxCFS gave a larger value.");
+  assert((FrameSDOps.empty() || MF.getFrameInfo().adjustsStack()) &&
+         "AdjustsStack not set in presence of a frame pseudo instruction.");
 
   if (TFI->canSimplifyCallFramePseudos(MF)) {
     // If call frames are not being included as part of the stack frame, and