[llvm] [TableGen][GISel] Reuse `importNodeRenderer` for `OperandWithDefaultOps` (PR #121285)

Sergei Barannikov via llvm-commits llvm-commits at lists.llvm.org
Sat Jan 4 12:17:58 PST 2025


https://github.com/s-barannikov updated https://github.com/llvm/llvm-project/pull/121285

>From 0690683a4f5b7a03e77012c954edd528134bbb42 Mon Sep 17 00:00:00 2001
From: Sergei Barannikov <barannikov88 at gmail.com>
Date: Sun, 29 Dec 2024 10:35:06 +0300
Subject: [PATCH 1/2] [TableGen][GISel] Reuse `importNodeRenderer` for
 `OperandWithDefaultOps`

This avoids some code duplication (handling `Register`, `zero_reg` and
immediate operands).
---
 llvm/utils/TableGen/GlobalISelEmitter.cpp | 77 +++++++----------------
 1 file changed, 24 insertions(+), 53 deletions(-)

diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index 092cdd4ad5b435..9f244ca804a08c 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -418,7 +418,8 @@ class GlobalISelEmitter final : public GlobalISelMatchTableExecutorEmitter {
                                 const TreePatternNode &N) const;
 
   Error importLeafNodeRenderer(RuleMatcher &M, BuildMIAction &MIBuilder,
-                               const TreePatternNode &N) const;
+                               const TreePatternNode &N,
+                               action_iterator InsertPt) const;
 
   Error importXFormNodeRenderer(RuleMatcher &M, BuildMIAction &MIBuilder,
                                 const TreePatternNode &N) const;
@@ -431,9 +432,6 @@ class GlobalISelEmitter final : public GlobalISelMatchTableExecutorEmitter {
                            const TreePatternNode &N,
                            action_iterator &InsertPt) const;
 
-  Error importDefaultOperandRenderers(action_iterator InsertPt, RuleMatcher &M,
-                                      BuildMIAction &DstMIBuilder,
-                                      const DAGDefaultOperand &DefaultOp) const;
   Error importImplicitDefRenderers(BuildMIAction &DstMIBuilder,
                                    ArrayRef<const Record *> ImplicitDefs) const;
 
@@ -1291,7 +1289,8 @@ Error GlobalISelEmitter::importNamedNodeRenderer(
 
 // Equivalent of MatcherGen::EmitResultLeafAsOperand.
 Error GlobalISelEmitter::importLeafNodeRenderer(
-    RuleMatcher &M, BuildMIAction &MIBuilder, const TreePatternNode &N) const {
+    RuleMatcher &M, BuildMIAction &MIBuilder, const TreePatternNode &N,
+    action_iterator InsertPt) const {
   if (const auto *II = dyn_cast<IntInit>(N.getLeafValue())) {
     MIBuilder.addRenderer<ImmRenderer>(II->getValue());
     return Error::success();
@@ -1300,11 +1299,24 @@ Error GlobalISelEmitter::importLeafNodeRenderer(
   if (const auto *DI = dyn_cast<DefInit>(N.getLeafValue())) {
     const Record *R = DI->getDef();
 
-    if (R->isSubClassOf("Register")) {
+    if (R->isSubClassOf("Register") || R->getName() == "zero_reg") {
       MIBuilder.addRenderer<AddRegisterRenderer>(Target, R);
       return Error::success();
     }
 
+    if (R->getName() == "undef_tied_input") {
+      std::optional<LLTCodeGen> OpTyOrNone = MVTToLLT(N.getSimpleType(0));
+      unsigned TempRegID = M.allocateTempRegID();
+      M.insertAction<MakeTempRegisterAction>(InsertPt, *OpTyOrNone, TempRegID);
+      auto I = M.insertAction<BuildMIAction>(
+          InsertPt, M.allocateOutputInsnID(),
+          &Target.getInstruction(RK.getDef("IMPLICIT_DEF")));
+      auto &ImpDefBuilder = static_cast<BuildMIAction &>(**I);
+      ImpDefBuilder.addRenderer<TempRegRenderer>(TempRegID, /*IsDef=*/true);
+      MIBuilder.addRenderer<TempRegRenderer>(TempRegID);
+      return Error::success();
+    }
+
     if (R->isSubClassOf("SubRegIndex")) {
       const CodeGenSubRegIndex *SubRegIndex = CGRegs.getSubRegIdx(R);
       MIBuilder.addRenderer<ImmRenderer>(SubRegIndex->EnumValue);
@@ -1386,7 +1398,7 @@ Error GlobalISelEmitter::importNodeRenderer(RuleMatcher &M,
     return importNamedNodeRenderer(M, MIBuilder, N);
 
   if (N.isLeaf())
-    return importLeafNodeRenderer(M, MIBuilder, N);
+    return importLeafNodeRenderer(M, MIBuilder, N, InsertPt);
 
   if (N.getOperator()->isSubClassOf("SDNodeXForm"))
     return importXFormNodeRenderer(M, MIBuilder, N);
@@ -1707,11 +1719,11 @@ Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderers(
       // This is a predicate or optional def operand which the pattern has not
       // overridden, or which we aren't letting it override; emit the 'default
       // ops' operands.
-
-      const Record *OperandNode = DstI->Operands[InstOpNo].Rec;
-      if (auto Error = importDefaultOperandRenderers(
-              InsertPt, M, DstMIBuilder, CGP.getDefaultOperand(OperandNode)))
-        return std::move(Error);
+      for (const TreePatternNode &OpNode :
+           make_pointee_range(CGP.getDefaultOperand(OperandNode).DefaultOps)) {
+        if (Error Err = importNodeRenderer(M, DstMIBuilder, OpNode, InsertPt))
+          return Err;
+      }
 
       ++NumDefaultOps;
       continue;
@@ -1734,47 +1746,6 @@ Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderers(
   return InsertPt;
 }
 
-Error GlobalISelEmitter::importDefaultOperandRenderers(
-    action_iterator InsertPt, RuleMatcher &M, BuildMIAction &DstMIBuilder,
-    const DAGDefaultOperand &DefaultOp) const {
-  for (const auto &Op : DefaultOp.DefaultOps) {
-    const auto &N = *Op;
-    if (!N.isLeaf())
-      return failedImport("Could not add default op");
-
-    const auto *DefaultOp = N.getLeafValue();
-
-    if (const DefInit *DefaultDefOp = dyn_cast<DefInit>(DefaultOp)) {
-      std::optional<LLTCodeGen> OpTyOrNone = MVTToLLT(N.getSimpleType(0));
-      auto *Def = DefaultDefOp->getDef();
-      if (Def->getName() == "undef_tied_input") {
-        unsigned TempRegID = M.allocateTempRegID();
-        M.insertAction<MakeTempRegisterAction>(InsertPt, *OpTyOrNone,
-                                               TempRegID);
-        InsertPt = M.insertAction<BuildMIAction>(
-            InsertPt, M.allocateOutputInsnID(),
-            &Target.getInstruction(RK.getDef("IMPLICIT_DEF")));
-        BuildMIAction &IDMIBuilder =
-            *static_cast<BuildMIAction *>(InsertPt->get());
-        IDMIBuilder.addRenderer<TempRegRenderer>(TempRegID, /*IsDef=*/true);
-        DstMIBuilder.addRenderer<TempRegRenderer>(TempRegID);
-      } else {
-        DstMIBuilder.addRenderer<AddRegisterRenderer>(Target, Def);
-      }
-      continue;
-    }
-
-    if (const IntInit *DefaultIntOp = dyn_cast<IntInit>(DefaultOp)) {
-      DstMIBuilder.addRenderer<ImmRenderer>(DefaultIntOp->getValue());
-      continue;
-    }
-
-    return failedImport("Could not add default op");
-  }
-
-  return Error::success();
-}
-
 Error GlobalISelEmitter::importImplicitDefRenderers(
     BuildMIAction &DstMIBuilder, ArrayRef<const Record *> ImplicitDefs) const {
   if (!ImplicitDefs.empty())

>From daa7154005a9ce0fa9cc3d505dd2aa5ec3abd04f Mon Sep 17 00:00:00 2001
From: Sergei Barannikov <barannikov88 at gmail.com>
Date: Sat, 4 Jan 2025 23:13:21 +0300
Subject: [PATCH 2/2] Check std::optional before dereferencing

---
 .../GlobalISelEmitter/undef-tied-input.td       | 17 ++++++++++++++---
 llvm/utils/TableGen/GlobalISelEmitter.cpp       |  5 +++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/llvm/test/TableGen/GlobalISelEmitter/undef-tied-input.td b/llvm/test/TableGen/GlobalISelEmitter/undef-tied-input.td
index a2ee3dc311772c..323aea9e396d16 100644
--- a/llvm/test/TableGen/GlobalISelEmitter/undef-tied-input.td
+++ b/llvm/test/TableGen/GlobalISelEmitter/undef-tied-input.td
@@ -1,14 +1,25 @@
-// RUN: llvm-tblgen -gen-global-isel -I %p/../../../include -I %p/../Common %s | FileCheck %s
+// RUN: llvm-tblgen -gen-global-isel -warn-on-skipped-patterns \
+// RUN:   -I %p/../../../include -I %p/../Common %s 2> %t | FileCheck %s
+// RUN: FileCheck -check-prefix=ERR %s < %t
 
 include "llvm/Target/Target.td"
 include "GlobalISelEmitterCommon.td"
 
-def undef_tied : OperandWithDefaultOps<untyped, (ops (i32 undef_tied_input))> {
+def undef_tied_1 : OperandWithDefaultOps<untyped, (ops (i32 undef_tied_input))> {
   let MIOperandInfo = (ops GPR32:$inactive);
 }
 
+def undef_tied_2 : OperandWithDefaultOps<i32, (ops (untyped undef_tied_input))> {
+  let MIOperandInfo = (ops GPR32:$inactive);
+}
+
+let Constraints = "$opt.inactive = $rd" in
+def I1 : I<(outs GPR32:$rd), (ins GPR32:$rs, undef_tied_1:$opt),
+           [(set GPR32:$rd, (abs i32:$rs))]>;
+
+// ERR: [[#@LINE+2]]:5: warning: Skipped pattern: unsupported type
 let Constraints = "$opt.inactive = $rd" in
-def I1 : I<(outs GPR32:$rd), (ins GPR32:$rs, undef_tied:$opt),
+def I2 : I<(outs GPR32:$rd), (ins GPR32:$rs, undef_tied_2:$opt),
            [(set GPR32:$rd, (abs i32:$rs))]>;
 
 // CHECK-LABEL: // (abs:{ *:[i32] } i32:{ *:[i32] }:$rs)  =>  (I1:{ *:[i32] } i32:{ *:[i32] }:$rs)
diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index 9f244ca804a08c..9f6d3a506dceb7 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -1306,13 +1306,18 @@ Error GlobalISelEmitter::importLeafNodeRenderer(
 
     if (R->getName() == "undef_tied_input") {
       std::optional<LLTCodeGen> OpTyOrNone = MVTToLLT(N.getSimpleType(0));
+      if (!OpTyOrNone)
+        return failedImport("unsupported type");
+
       unsigned TempRegID = M.allocateTempRegID();
       M.insertAction<MakeTempRegisterAction>(InsertPt, *OpTyOrNone, TempRegID);
+
       auto I = M.insertAction<BuildMIAction>(
           InsertPt, M.allocateOutputInsnID(),
           &Target.getInstruction(RK.getDef("IMPLICIT_DEF")));
       auto &ImpDefBuilder = static_cast<BuildMIAction &>(**I);
       ImpDefBuilder.addRenderer<TempRegRenderer>(TempRegID, /*IsDef=*/true);
+
       MIBuilder.addRenderer<TempRegRenderer>(TempRegID);
       return Error::success();
     }



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