From adcf8c9b1bd1b47e00bf859693112cea1f7e8c9f Mon Sep 17 00:00:00 2001
From: Richard-Qin-X <richard.qin.001@gmail.com>
Date: Mon, 10 Aug 2026 20:36:50 +0800
Subject: [Tooling] Complete backend tooling and validation

---
 backend/lib/CodeGen/InlineSpiller.cpp | 45 +++++++++++++++++++++++++++++++----
 1 file changed, 41 insertions(+), 4 deletions(-)

(limited to 'backend/lib/CodeGen/InlineSpiller.cpp')

diff --git a/backend/lib/CodeGen/InlineSpiller.cpp b/backend/lib/CodeGen/InlineSpiller.cpp
index 589b7b8..14de321 100644
--- a/backend/lib/CodeGen/InlineSpiller.cpp
+++ b/backend/lib/CodeGen/InlineSpiller.cpp
@@ -7,6 +7,7 @@
 #include "rcc/CodeGen/MachineIRBuilder.h"
 #include "rcc/CodeGen/MachineInstr.h"
 #include "rcc/CodeGen/MachineOperand.h"
+#include "rcc/CodeGen/MachinePass.h"
 #include "rcc/CodeGen/MachineRegisterInfo.h"
 #include "rcc/CodeGen/Spiller.h"
 #include "rcc/CodeGen/TargetDescription.h"
@@ -42,11 +43,11 @@ Expected<std::optional<std::vector<Register>>> Spiller::tryRematerialize(Registe
   const MachineInstr *DefiningInstruction = Definition == nullptr ? nullptr : Definition->parent();
   if (DefiningInstruction == nullptr || DefiningInstruction->parent() == nullptr)
     return std::optional<std::vector<Register>>{};
-  auto Accepted =
+  auto Rematerializable =
       TargetInfo->isRematerializable(*DefiningInstruction, VirtualReg, *Function, *Target);
-  if (!Accepted)
-    return std::unexpected(Accepted.error());
-  if (!*Accepted)
+  if (!Rematerializable)
+    return std::unexpected(Rematerializable.error());
+  if (!*Rematerializable)
     return std::optional<std::vector<Register>>{};
 
   struct UseSite final {
@@ -77,6 +78,16 @@ Expected<std::optional<std::vector<Register>>> Spiller::tryRematerialize(Registe
   if (Sites.empty())
     return std::optional<std::vector<Register>>{};
 
+  if (Actions != nullptr) {
+    for (const UseSite &Site : Sites) {
+      auto Accepted = Actions->request("rematerialize", *Function, Site.Instruction->stableID());
+      if (!Accepted)
+        return std::unexpected(Accepted.error());
+      if (!*Accepted)
+        return std::optional<std::vector<Register>>{};
+    }
+  }
+
   std::vector<Register> NewRegisters;
   NewRegisters.reserve(Sites.size());
   for (UseSite &Site : Sites) {
@@ -169,6 +180,19 @@ Expected<std::vector<Register>> Spiller::spillAtInstructions(Register VirtualReg
   }
 
   std::vector<Register> NewRegisters;
+  if (Actions != nullptr) {
+    for (const SpillSite &Site : Sites) {
+      if (Site.OperandIndices.empty())
+        continue;
+      auto Accepted = Actions->request("split-live-range", *Function, Site.Instruction->stableID());
+      if (!Accepted)
+        return std::unexpected(Accepted.error());
+      if (!*Accepted) {
+        return makeUnexpected(ErrorCode::RegisterAllocationFailed,
+                              "required live-range split action was rejected");
+      }
+    }
+  }
   for (SpillSite &Site : Sites) {
     for (const std::size_t Index : Site.DebugIndices) {
       MachineOperand *Operand = Site.Instruction->operandAt(Index);
@@ -259,6 +283,19 @@ Expected<std::vector<Register>> Spiller::spill(Register VirtualReg) {
     return makeUnexpected(ErrorCode::RegisterAllocationFailed,
                           "register pressure requires spilling a non-spillable value");
   }
+  if (Actions != nullptr) {
+    const MachineOperand *Definition = Function->registerInfo().getUniqueVRegDef(VirtualReg);
+    const MachineInstr *Instruction = Definition == nullptr ? nullptr : Definition->parent();
+    auto Accepted =
+        Actions->request("spill", *Function,
+                         Instruction == nullptr ? MachineInstrStableID{} : Instruction->stableID());
+    if (!Accepted)
+      return std::unexpected(Accepted.error());
+    if (!*Accepted) {
+      return makeUnexpected(ErrorCode::RegisterAllocationFailed,
+                            "required spill action was rejected");
+    }
+  }
   auto Rematerialized = tryRematerialize(VirtualReg);
   if (!Rematerialized)
     return std::unexpected(Rematerialized.error());
-- 
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