[TableGen][GISel] Handle frameindex/tframeindex

[redstar]

Support patterns like

Pat<(p0 frameindex:$fi), (ADD tframeindex:$fi, 0)>;

in the GlobalISel emitter in TableGen. Currently, using such a pattern results in an error message.

[llvmbot]

@llvm/pr-subscribers-llvm-globalisel

Author: Kai Nacke (redstar)

Changes

Support patterns like

Pat<(p0 frameindex:$fi), (ADD tframeindex:$fi, 0)>;

in the GlobalISel emitter in TableGen. Currently, using such a pattern results in an error message.

---

Full diff: https://github.com/llvm/llvm-project/pull/90475.diff

2 Files Affected:

• (added) llvm/test/TableGen/GlobalISelEmitter-frameindex.td (+29)
• (modified) llvm/utils/TableGen/GlobalISelEmitter.cpp (+9)

diff --git a/llvm/test/TableGen/GlobalISelEmitter-frameindex.td b/llvm/test/TableGen/GlobalISelEmitter-frameindex.td
new file mode 100644
index 00000000000000..232691465bb3bd
--- /dev/null
+++ b/llvm/test/TableGen/GlobalISelEmitter-frameindex.td
@@ -0,0 +1,29 @@
+// RUN: llvm-tblgen -gen-global-isel -optimize-match-table=false -I %p/../../include -I %p/Common %s -o - < %s | FileCheck %s
+
+include "llvm/Target/Target.td"
+include "GlobalISelEmitterCommon.td"
+
+def ADD : I<(outs GPR32:$dst), (ins GPR32:$src1, GPR32:$src2), []>;
+
+//===- Test a simple pattern with frame index operands. ----------------------===//
+//
+// CHECK:       GIM_Try, /*On fail goto*//*Label [[LABEL_NUM:[0-9]+]]*/ GIMT_Encode4([[LABEL:[0-9]+]]),
+// CHECK-NEXT:    GIM_CheckNumOperands, /*MI*/0, /*Expected*/2,
+// CHECK-NEXT:    GIM_CheckOpcode, /*MI*/0, GIMT_Encode2(TargetOpcode::G_FRAME_INDEX),
+// CHECK-NEXT:    // MIs[0] DstI[dst]
+// CHECK-NEXT:    GIM_RootCheckType, /*Op*/0, /*Type*/GILLT_p0s32,
+// CHECK-NEXT:    GIM_RootCheckRegBankForClass, /*Op*/0, /*RC*/GIMT_Encode2(MyTarget::GPR32RegClassID),
+// CHECK-NEXT:    // MIs[0] fi
+// CHECK-NEXT:    // No operand predicates
+// CHECK-NEXT:    // (frameindex:{ *:[i32] }):$fi  =>  (ADD:{ *:[i32] } (tframeindex:{ *:[i32] }):$fi, 0:{ *:[i32] })
+// CHECK-NEXT:    GIR_BuildRootMI, /*Opcode*/GIMT_Encode2(MyTarget::ADD),
+// CHECK-NEXT:    GIR_RootToRootCopy, /*OpIdx*/0, // DstI[dst]
+// CHECK-NEXT:    GIR_RootToRootCopy, /*OpIdx*/1, // fi
+// CHECK-NEXT:    GIR_AddImm8, /*InsnID*/0, /*Imm*/0,
+// CHECK-NEXT:    GIR_RootConstrainSelectedInstOperands,
+// CHECK-NEXT:    // GIR_Coverage, 0,
+// CHECK-NEXT:    GIR_EraseRootFromParent_Done,
+// CHECK-NEXT:  // Label [[LABEL_NUM]]: @[[LABEL]]
+// CHECK-NEXT:  GIM_Reject,
+
+def : Pat<(p0 frameindex:$fi), (ADD tframeindex:$fi, 0)>;
diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index 78abf80e7aecb3..0eb258ff89a288 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -834,6 +834,11 @@ Expected<InstructionMatcher &> GlobalISelEmitter::createAndImportSelDAGMatcher(
       return InsnMatcher;
     }
 
+    if (SrcGIOrNull->TheDef->getName() == "G_FRAME_INDEX") {
+      InsnMatcher.addOperand(OpIdx++, Src.getName(), TempOpIdx);
+      return InsnMatcher;
+    }
+
     // Special case because the operand order is changed from setcc. The
     // predicate operand needs to be swapped from the last operand to the first
     // source.
@@ -1223,6 +1228,10 @@ Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderer(
     if (DstChild.getOperator()->getName() == "timm") {
       DstMIBuilder.addRenderer<CopyRenderer>(DstChild.getName());
       return InsertPt;
+    }
+    if (DstChild.getOperator()->getName() == "tframeindex") {
+      DstMIBuilder.addRenderer<CopyRenderer>(DstChild.getName());
+      return InsertPt;
     } else if (DstChild.getOperator()->getName() == "imm") {
       DstMIBuilder.addRenderer<CopyConstantAsImmRenderer>(DstChild.getName());
       return InsertPt;

[arsenm]

No else after return, but I guess this was already violated

[redstar]

Yeah, there is already a whole sequence of else if statements following returns.