[clang] [llvm] [AMDGPU] Convert AMDGPUResourceUsageAnalysis pass from Module to MF pass (PR #102913)

[Matt Arsenault via cfe-commits]

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@@ -0,0 +1,225 @@
+//===- AMDGPUMCResourceInfo.cpp --- MC Resource Info ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// \brief MC infrastructure to propagate the function level resource usage
+/// info.
+///
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPUMCResourceInfo.h"
+#include "Utils/AMDGPUBaseInfo.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCSymbol.h"
+
+using namespace llvm;
+
+MCSymbol *MCResourceInfo::getSymbol(StringRef FuncName, ResourceInfoKind RIK,
+                                    MCContext &OutContext) {
+  auto GOCS = [this, FuncName, &OutContext](StringRef Suffix) {
+    return OutContext.getOrCreateSymbol(FuncName + Twine(Suffix));
+  };
+  switch (RIK) {
+  case RIK_NumVGPR:
+    return GOCS(".num_vgpr");
+  case RIK_NumAGPR:
+    return GOCS(".num_agpr");
+  case RIK_NumSGPR:
+    return GOCS(".numbered_sgpr");
+  case RIK_PrivateSegSize:
+    return GOCS(".private_seg_size");
+  case RIK_UsesVCC:
+    return GOCS(".uses_vcc");
+  case RIK_UsesFlatScratch:
+    return GOCS(".uses_flat_scratch");
+  case RIK_HasDynSizedStack:
+    return GOCS(".has_dyn_sized_stack");
+  case RIK_HasRecursion:
+    return GOCS(".has_recursion");
+  case RIK_HasIndirectCall:
+    return GOCS(".has_indirect_call");
+  }
+  llvm_unreachable("Unexpected ResourceInfoKind.");
+}
+
+const MCExpr *MCResourceInfo::getSymRefExpr(StringRef FuncName,
+                                            ResourceInfoKind RIK,
+                                            MCContext &Ctx) {
+  return MCSymbolRefExpr::create(getSymbol(FuncName, RIK, Ctx), Ctx);
+}
+
+void MCResourceInfo::assignMaxRegs(MCContext &OutContext) {
+  // Assign expression to get the max register use to the max_num_Xgpr symbol.
+  MCSymbol *MaxVGPRSym = getMaxVGPRSymbol(OutContext);
+  MCSymbol *MaxAGPRSym = getMaxAGPRSymbol(OutContext);
+  MCSymbol *MaxSGPRSym = getMaxSGPRSymbol(OutContext);
+
+  auto assignMaxRegSym = [this, &OutContext](MCSymbol *Sym, int32_t RegCount) {
+    const MCExpr *MaxExpr = MCConstantExpr::create(RegCount, OutContext);
+    Sym->setVariableValue(MaxExpr);
+  };
+
+  assignMaxRegSym(MaxVGPRSym, MaxVGPR);
+  assignMaxRegSym(MaxAGPRSym, MaxAGPR);
+  assignMaxRegSym(MaxSGPRSym, MaxSGPR);
+}
+
+void MCResourceInfo::finalize(MCContext &OutContext) {
+  assert(!Finalized && "Cannot finalize ResourceInfo again.");
+  Finalized = true;
+  assignMaxRegs(OutContext);
+}
+
+MCSymbol *MCResourceInfo::getMaxVGPRSymbol(MCContext &OutContext) {
+  return OutContext.getOrCreateSymbol("max_num_vgpr");
+}
+
+MCSymbol *MCResourceInfo::getMaxAGPRSymbol(MCContext &OutContext) {
+  return OutContext.getOrCreateSymbol("max_num_agpr");
+}
+
+MCSymbol *MCResourceInfo::getMaxSGPRSymbol(MCContext &OutContext) {
+  return OutContext.getOrCreateSymbol("max_num_sgpr");
+}
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arsenm wrote:

I wonder if these should be placed in a custom section. In any case, we will eventually need custom linker logic to deal with this 

https://github.com/llvm/llvm-project/pull/102913