[llvm] [AMDGPU] Add AMDGPU specific variadic operation MCExprs (PR #82022)

Janek van Oirschot via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 16 10:37:49 PST 2024


https://github.com/JanekvO created https://github.com/llvm/llvm-project/pull/82022

Adds AMDGPU specific variadic MCExpr operations 'max' and 'or'. Required for moving function/program resource usage information propagation to MC layer as propagation of the maximum and logic OR values will go through MCExprs. Propagation of said resource usage info through these MCExpr operations compared to current handling in AMDGPUResourceUsageAnalysis will ease the constraint on the order for a function's resource usage analysis as the symbolic definition of a resource can occur after its use.

>From a47ee7ba1bac1bd0c8a4384d5f3bef7011286fea Mon Sep 17 00:00:00 2001
From: Janek van Oirschot <janek.vanoirschot at amd.com>
Date: Fri, 16 Feb 2024 17:01:44 +0000
Subject: [PATCH] AMDGPU Variadic MCExprs

---
 .../AMDGPU/AsmParser/AMDGPUAsmParser.cpp      | 49 ++++++++++
 .../AMDGPU/MCTargetDesc/AMDGPUMCExpr.cpp      | 92 +++++++++++++++++++
 .../Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.h | 64 +++++++++++++
 .../Target/AMDGPU/MCTargetDesc/CMakeLists.txt |  1 +
 llvm/test/MC/AMDGPU/mcexpr_amd.s              | 92 +++++++++++++++++++
 llvm/test/MC/AMDGPU/mcexpr_amd_err.s          | 26 ++++++
 6 files changed, 324 insertions(+)
 create mode 100644 llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.cpp
 create mode 100644 llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.h
 create mode 100644 llvm/test/MC/AMDGPU/mcexpr_amd.s
 create mode 100644 llvm/test/MC/AMDGPU/mcexpr_amd_err.s

diff --git a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
index 79ad6ddf7861fc..c878d9d26988e9 100644
--- a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
+++ b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "AMDKernelCodeT.h"
+#include "MCTargetDesc/AMDGPUMCExpr.h"
 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
 #include "MCTargetDesc/AMDGPUTargetStreamer.h"
 #include "SIDefines.h"
@@ -1745,6 +1746,7 @@ class AMDGPUAsmParser : public MCTargetAsmParser {
 
 public:
   void onBeginOfFile() override;
+  bool parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) override;
 
   ParseStatus parseCustomOperand(OperandVector &Operands, unsigned MCK);
 
@@ -8130,6 +8132,53 @@ void AMDGPUAsmParser::onBeginOfFile() {
     getTargetStreamer().EmitDirectiveAMDGCNTarget();
 }
 
+/// Parse AMDGPU specific expressions.
+///
+///  expr ::= or(expr, ...) |
+///           max(expr, ...)
+///
+bool AMDGPUAsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
+  using AGVK = AMDGPUVariadicMCExpr::AMDGPUVariadicKind;
+
+  auto parseVariadicExpr = [&](AGVK Kind, const MCExpr *&res, SMLoc &EndLoc) {
+    std::vector<const MCExpr *> Exprs;
+    while (true) {
+      if (isToken(AsmToken::RParen)) {
+        if (Exprs.empty()) {
+          Error(getToken().getLoc(), "empty max/or expression");
+          return true;
+        }
+        lex();
+        res = AMDGPUVariadicMCExpr::create(Kind, Exprs, getContext());
+        return false;
+      }
+      const MCExpr *Expr;
+      if (getParser().parseExpression(Expr, EndLoc))
+        return true;
+      Exprs.push_back(Expr);
+      if (!trySkipToken(AsmToken::Comma) && !isToken(AsmToken::RParen)) {
+        Error(getToken().getLoc(), "unexpected token in max/or expression");
+        return true;
+      }
+    }
+  };
+
+  if (isToken(AsmToken::Identifier)) {
+    StringRef TokenId = getTokenStr();
+    AGVK VK = StringSwitch<AGVK>(TokenId)
+                  .Case("max", AGVK::AGVK_Max)
+                  .Case("or", AGVK::AGVK_Or)
+                  .Default(AGVK::AGVK_None);
+
+    if (VK != AGVK::AGVK_None && peekToken().is(AsmToken::LParen)) {
+      lex(); // Eat 'max'/'or'
+      lex(); // Eat '('
+      return parseVariadicExpr(VK, Res, EndLoc);
+    }
+  }
+  return getParser().parsePrimaryExpr(Res, EndLoc, nullptr);
+}
+
 ParseStatus AMDGPUAsmParser::parseOModSI(OperandVector &Operands) {
   StringRef Name = getTokenStr();
   if (Name == "mul") {
diff --git a/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.cpp b/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.cpp
new file mode 100644
index 00000000000000..3b00de3756d924
--- /dev/null
+++ b/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.cpp
@@ -0,0 +1,92 @@
+//===- AMDGPUMCExpr.cpp - AMDGPU specific MC expression classes -----------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPUMCExpr.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+const AMDGPUVariadicMCExpr *
+AMDGPUVariadicMCExpr::create(AMDGPUVariadicKind Kind,
+                             const std::vector<const MCExpr *> &Args,
+                             MCContext &Ctx) {
+  return new (Ctx) AMDGPUVariadicMCExpr(Kind, Args);
+}
+
+const MCExpr *AMDGPUVariadicMCExpr::getSubExpr(size_t index) const {
+  assert(index < Args.size() &&
+         "Indexing out of bounds AMDGPUVariadicMCExpr sub-expr");
+  return Args[index];
+}
+
+void AMDGPUVariadicMCExpr::printImpl(raw_ostream &OS,
+                                     const MCAsmInfo *MAI) const {
+  switch (Kind) {
+  default:
+    llvm_unreachable("Unknown AMDGPUVariadicMCExpr kind.");
+  case AGVK_Or:
+    OS << "or(";
+    break;
+  case AGVK_Max:
+    OS << "max(";
+    break;
+  }
+  for (auto it = Args.begin(); it != Args.end(); ++it) {
+    (*it)->print(OS, MAI, /*InParens=*/false);
+    if ((it + 1) != Args.end())
+      OS << ", ";
+  }
+  OS << ")";
+}
+
+bool AMDGPUVariadicMCExpr::evaluateAsRelocatableImpl(
+    MCValue &Res, const MCAsmLayout *Layout, const MCFixup *Fixup) const {
+  int64_t total = 0;
+
+  auto Op = [this](int64_t Arg1, int64_t Arg2) -> int64_t {
+    switch (Kind) {
+    default:
+      llvm_unreachable("Unknown AMDGPUVariadicMCExpr kind.");
+    case AGVK_Max:
+      return Arg1 > Arg2 ? Arg1 : Arg2;
+    case AGVK_Or:
+      return (!!Arg1) || (!!Arg2);
+    }
+  };
+
+  for (const MCExpr *Arg : Args) {
+    MCValue ArgRes;
+    if (!Arg->evaluateAsRelocatable(ArgRes, Layout, Fixup))
+      return false;
+    if (!ArgRes.isAbsolute())
+      return false;
+    total = Op(total, ArgRes.getConstant());
+  }
+
+  Res = MCValue::get(total);
+  return true;
+}
+
+void AMDGPUVariadicMCExpr::visitUsedExpr(MCStreamer &Streamer) const {
+  for (const MCExpr *Arg : Args) {
+    Streamer.visitUsedExpr(*Arg);
+  }
+}
+
+MCFragment *AMDGPUVariadicMCExpr::findAssociatedFragment() const {
+  for (const MCExpr *Arg : Args) {
+    if (Arg->findAssociatedFragment())
+      return Arg->findAssociatedFragment();
+  }
+  return nullptr;
+}
diff --git a/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.h b/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.h
new file mode 100644
index 00000000000000..acd1dc47934bad
--- /dev/null
+++ b/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCExpr.h
@@ -0,0 +1,64 @@
+//===- AMDGPUMCExpr.h - AMDGPU specific MC expression classes ---*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUMCEXPR_H
+#define LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUMCEXPR_H
+
+#include "llvm/MC/MCExpr.h"
+
+namespace llvm {
+
+class AMDGPUMCExpr : public MCTargetExpr {
+  static bool classof(const MCExpr *E) {
+    return E->getKind() == MCExpr::Target;
+  }
+  void fixELFSymbolsInTLSFixups(MCAssembler &) const override{};
+};
+
+class AMDGPUVariadicMCExpr : public AMDGPUMCExpr {
+public:
+  enum AMDGPUVariadicKind { AGVK_None, AGVK_Or, AGVK_Max };
+
+private:
+  AMDGPUVariadicKind Kind;
+  std::vector<const MCExpr *> Args;
+
+  AMDGPUVariadicMCExpr(AMDGPUVariadicKind Kind,
+                       const std::vector<const MCExpr *> &Args)
+      : Kind(Kind), Args(Args) {
+    assert(Args.size() >= 1 && "Can't take the maximum of 0 expressions.");
+  }
+
+public:
+  static const AMDGPUVariadicMCExpr *
+  create(AMDGPUVariadicKind Kind, const std::vector<const MCExpr *> &Args,
+         MCContext &Ctx);
+
+  static const AMDGPUVariadicMCExpr *
+  createOr(const std::vector<const MCExpr *> &Args, MCContext &Ctx) {
+    return create(AMDGPUVariadicKind::AGVK_Or, Args, Ctx);
+  }
+
+  static const AMDGPUVariadicMCExpr *
+  createMax(const std::vector<const MCExpr *> &Args, MCContext &Ctx) {
+    return create(AMDGPUVariadicKind::AGVK_Max, Args, Ctx);
+  }
+
+  AMDGPUVariadicKind getKind() const { return Kind; }
+  const MCExpr *getSubExpr(size_t index) const;
+
+  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
+  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
+                                 const MCFixup *Fixup) const override;
+  void visitUsedExpr(MCStreamer &Streamer) const override;
+  MCFragment *findAssociatedFragment() const override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUMCEXPR_H
\ No newline at end of file
diff --git a/llvm/lib/Target/AMDGPU/MCTargetDesc/CMakeLists.txt b/llvm/lib/Target/AMDGPU/MCTargetDesc/CMakeLists.txt
index 5dc76071b0594e..0842a58f794b32 100644
--- a/llvm/lib/Target/AMDGPU/MCTargetDesc/CMakeLists.txt
+++ b/llvm/lib/Target/AMDGPU/MCTargetDesc/CMakeLists.txt
@@ -5,6 +5,7 @@ add_llvm_component_library(LLVMAMDGPUDesc
   AMDGPUInstPrinter.cpp
   AMDGPUMCAsmInfo.cpp
   AMDGPUMCCodeEmitter.cpp
+  AMDGPUMCExpr.cpp
   AMDGPUMCTargetDesc.cpp
   AMDGPUTargetStreamer.cpp
   R600InstPrinter.cpp
diff --git a/llvm/test/MC/AMDGPU/mcexpr_amd.s b/llvm/test/MC/AMDGPU/mcexpr_amd.s
new file mode 100644
index 00000000000000..a201c35e8d2caf
--- /dev/null
+++ b/llvm/test/MC/AMDGPU/mcexpr_amd.s
@@ -0,0 +1,92 @@
+// RUN: llvm-mc -triple amdgcn-amd-amdhsa < %s | FileCheck --check-prefix=ASM %s
+// RUN: llvm-mc -triple amdgcn-amd-amdhsa -filetype=obj < %s > %t
+// RUN: llvm-objdump --syms %t | FileCheck --check-prefix=OBJDUMP %s
+
+// OBJDUMP: SYMBOL TABLE:
+// OBJDUMP-NEXT: 0000000000000000 l       *ABS*  0000000000000000 zero
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 one
+// OBJDUMP-NEXT: 0000000000000002 l       *ABS*  0000000000000000 two
+// OBJDUMP-NEXT: 0000000000000003 l       *ABS*  0000000000000000 three
+// OBJDUMP-NEXT: 0000000000000005 l       *ABS*  0000000000000000 max_expression_all
+// OBJDUMP-NEXT: 0000000000000005 l       *ABS*  0000000000000000 five
+// OBJDUMP-NEXT: 0000000000000004 l       *ABS*  0000000000000000 four
+// OBJDUMP-NEXT: 0000000000000002 l       *ABS*  0000000000000000 max_expression_two
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 max_expression_one
+// OBJDUMP-NEXT: 000000000000000a l       *ABS*  0000000000000000 max_literals
+// OBJDUMP-NEXT: 000000000000000f l       *ABS*  0000000000000000 max_with_max_sym
+// OBJDUMP-NEXT: 000000000000000f l       *ABS*  0000000000000000 max
+// OBJDUMP-NEXT: 0000000000000003 l       *ABS*  0000000000000000 max_with_subexpr
+// OBJDUMP-NEXT: 0000000000000006 l       *ABS*  0000000000000000 max_as_subexpr
+// OBJDUMP-NEXT: 0000000000000005 l       *ABS*  0000000000000000 max_recursive_subexpr
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_expression_all
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_expression_two
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_expression_one
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_literals
+// OBJDUMP-NEXT: 0000000000000000 l       *ABS*  0000000000000000 or_false
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_with_or_sym
+// OBJDUMP-NEXT: 00000000000000ff l       *ABS*  0000000000000000 or
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_with_subexpr
+// OBJDUMP-NEXT: 0000000000000002 l       *ABS*  0000000000000000 or_as_subexpr
+// OBJDUMP-NEXT: 0000000000000001 l       *ABS*  0000000000000000 or_recursive_subexpr
+
+// ASM: .set zero, 0
+// ASM: .set one, 1
+// ASM: .set two, 2
+// ASM: .set three, 3
+
+.set zero, 0
+.set one, 1
+.set two, 2
+.set three, 3
+
+// ASM: .set max_expression_all, max(1, 2, five, 3, four)
+// ASM: .set max_expression_two, 2
+// ASM: .set max_expression_one, 1
+// ASM: .set max_literals, 10
+// ASM: .set max_with_max_sym, max(max, 4, 3, 1, 2)
+
+.set max_expression_all, max(one, two, five, three, four)
+.set max_expression_two, max(one, two)
+.set max_expression_one, max(one)
+.set max_literals, max(1,2,3,4,5,6,7,8,9,10)
+.set max_with_max_sym, max(max, 4, 3, one, two)
+
+// ASM: .set max_with_subexpr, 3
+// ASM: .set max_as_subexpr, 1+(max(4, 3, five))
+// ASM: .set max_recursive_subexpr, max(max(1, four), 3, max_expression_all)
+
+.set max_with_subexpr, max(((one | 3) << 3) / 8)
+.set max_as_subexpr, 1 + max(4, 3, five)
+.set max_recursive_subexpr, max(max(one, four), three, max_expression_all)
+
+// ASM: .set or_expression_all, or(1, 2, five, 3, four)
+// ASM: .set or_expression_two, 1
+// ASM: .set or_expression_one, 1
+// ASM: .set or_literals, 1
+// ASM: .set or_false, 0
+// ASM: .set or_with_or_sym, or(or, 4, 3, 1, 2)
+
+.set or_expression_all, or(one, two, five, three, four)
+.set or_expression_two, or(one, two)
+.set or_expression_one, or(one)
+.set or_literals, or(1,2,3,4,5,6,7,8,9,10)
+.set or_false, or(zero, 0, (2-2), 5 > 6)
+.set or_with_or_sym, or(or, 4, 3, one, two)
+
+// ASM: .set or_with_subexpr, 1
+// ASM: .set or_as_subexpr, 1+(or(4, 3, five))
+// ASM: .set or_recursive_subexpr, or(or(1, four), 3, or_expression_all)
+
+.set or_with_subexpr, or(((one | 3) << 3) / 8)
+.set or_as_subexpr, 1 + or(4, 3, five)
+.set or_recursive_subexpr, or(or(one, four), three, or_expression_all)
+
+// ASM: .set four, 4
+// ASM: .set five, 5
+// ASM: .set max, 15
+// ASM: .set or, 255
+
+.set four, 4
+.set five, 5
+.set max, 0xF
+.set or, 0xFF
diff --git a/llvm/test/MC/AMDGPU/mcexpr_amd_err.s b/llvm/test/MC/AMDGPU/mcexpr_amd_err.s
new file mode 100644
index 00000000000000..ffe1918399a7cc
--- /dev/null
+++ b/llvm/test/MC/AMDGPU/mcexpr_amd_err.s
@@ -0,0 +1,26 @@
+// RUN: not llvm-mc -triple amdgcn-amd-amdhsa %s 2>&1 | FileCheck --check-prefix=ASM %s
+
+// ASM: error: empty max/or expression
+// ASM: error: missing expression
+// ASM: error: unknown token in expression
+// ASM: error: missing expression
+// ASM: error: unexpected token in max/or expression
+// ASM: error: missing expression
+// ASM: error: unknown token in expression
+// ASM: error: missing expression
+// ASM: error: unexpected token in max/or expression
+// ASM: error: missing expression
+
+.set one, 1
+.set two, 2
+.set three, 3
+
+.set max_empty, max()
+.set max_post_aux_comma, max(one,)
+.set max_pre_aux_comma, max(,one)
+.set max_missing_paren, max(two
+.set max_expression_one, max(three, four,
+.set max_expression_one, max(four, five
+
+.set four, 4
+.set five, 5



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