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[TableGen][GISel] Fix importing frameindex node #120921

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Merged
merged 2 commits into from
Dec 23, 2024
Merged

[TableGen][GISel] Fix importing frameindex node #120921

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90d2cb9
[TableGen][GISel] Import frameindex correctly
s-barannikov Dec 22, 2024
5de72b7
Restore the check for `tframeindex`
s-barannikov Dec 23, 2024
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2 changes: 1 addition & 1 deletion llvm/include/llvm/Target/GenericOpcodes.td
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Original file line number Diff line number Diff line change
Expand Up @@ -99,7 +99,7 @@ def G_PHI : GenericInstruction {
}

def G_FRAME_INDEX : GenericInstruction {
let OutOperandList = (outs type0:$dst);
let OutOperandList = (outs ptype0:$dst);
let InOperandList = (ins unknown:$src2);
let hasSideEffects = false;
}
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88 changes: 63 additions & 25 deletions llvm/test/TableGen/GlobalISelEmitter-frameindex.td
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@@ -1,29 +1,67 @@
// RUN: llvm-tblgen -gen-global-isel -optimize-match-table=false -I %p/../../include -I %p/Common %s -o - < %s | FileCheck %s
// RUN: llvm-tblgen -gen-global-isel -optimize-match-table=false -I %p/../../include -I %p/Common %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)>;
def ADDI : I<(outs GPR32:$dst), (ins GPR32:$src1, i32imm:$src2), []>;

def to_tframeindex : SDNodeXForm<frameindex, [{}]>;

def : GICustomOperandRenderer<"renderFrameIndex">,
GISDNodeXFormEquiv<to_tframeindex>;

def : Pat<(frameindex:$fi), (ADDI (to_tframeindex $fi), 0)>;

def : Pat<(ptradd frameindex:$fi, (i32 imm:$offset)),
(ADDI (to_tframeindex $fi), imm:$offset)>;

// CHECK-LABEL: GIM_Try, /*On fail goto*//*Label 0*/ GIMT_Encode4(74), // Rule ID 1 //
// CHECK-NEXT: GIM_CheckNumOperands, /*MI*/0, /*Expected*/3,
// CHECK-NEXT: GIM_CheckOpcode, /*MI*/0, GIMT_Encode2(TargetOpcode::G_PTR_ADD),
// CHECK-NEXT: // MIs[0] DstI[dst]
// CHECK-NEXT: GIM_CheckPointerToAny, /*MI*/0, /*Op*/0, /*SizeInBits*/32,
// CHECK-NEXT: GIM_RootCheckRegBankForClass, /*Op*/0, /*RC*/GIMT_Encode2(MyTarget::GPR32RegClassID),
// CHECK-NEXT: // MIs[0] fi
// CHECK-NEXT: GIM_CheckPointerToAny, /*MI*/0, /*Op*/1, /*SizeInBits*/32,
// CHECK-NEXT: GIM_RecordInsn, /*DefineMI*/1, /*MI*/0, /*OpIdx*/1, // MIs[1]
// CHECK-NEXT: GIM_CheckNumOperands, /*MI*/1, /*Expected*/2,
// CHECK-NEXT: GIM_CheckOpcode, /*MI*/1, GIMT_Encode2(TargetOpcode::G_FRAME_INDEX),
// CHECK-NEXT: // MIs[1] Operand 0
// CHECK-NEXT: GIM_CheckPointerToAny, /*MI*/1, /*Op*/0, /*SizeInBits*/32,
// CHECK-NEXT: // MIs[1] Operand 1
// CHECK-NEXT: // No operand predicates
// CHECK-NEXT: // MIs[0] offset
// CHECK-NEXT: GIM_RootCheckType, /*Op*/2, /*Type*/GILLT_s32,
// CHECK-NEXT: GIM_RecordInsn, /*DefineMI*/2, /*MI*/0, /*OpIdx*/2, // MIs[2]
// CHECK-NEXT: GIM_CheckNumOperands, /*MI*/2, /*Expected*/2,
// CHECK-NEXT: GIM_CheckOpcode, /*MI*/2, GIMT_Encode2(TargetOpcode::G_CONSTANT),
// CHECK-NEXT: // MIs[2] Operand 0
// CHECK-NEXT: GIM_CheckType, /*MI*/2, /*Op*/0, /*Type*/GILLT_s32,
// CHECK-NEXT: // MIs[2] Operand 1
// CHECK-NEXT: // No operand predicates
// CHECK-NEXT: GIM_CheckIsSafeToFold, /*NumInsns*/2,
// CHECK-NEXT: // (ptradd:{ *:[i32] } (frameindex:{ *:[i32] }):$fi, (imm:{ *:[i32] }):$offset) => (ADDI:{ *:[i32] } (to_tframeindex:{ *:[i32] } ?:{ *:[i32] }:$fi), (imm:{ *:[i32] }):$offset)
// CHECK-NEXT: GIR_BuildRootMI, /*Opcode*/GIMT_Encode2(MyTarget::ADDI),
// CHECK-NEXT: GIR_RootToRootCopy, /*OpIdx*/0, // DstI[dst]
// CHECK-NEXT: GIR_CustomRenderer, /*InsnID*/0, /*OldInsnID*/1, /*Renderer*/GIMT_Encode2(GICR_renderFrameIndex), // fi
// CHECK-NEXT: GIR_CopyConstantAsSImm, /*NewInsnID*/0, /*OldInsnID*/2, // offset
// CHECK-NEXT: GIR_RootConstrainSelectedInstOperands,
// CHECK-NEXT: // GIR_Coverage, 1,
// CHECK-NEXT: GIR_EraseRootFromParent_Done,

// CHECK-LABEL: GIM_Try, /*On fail goto*//*Label 1*/ GIMT_Encode4(109), // Rule ID 0 //
// 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_CheckPointerToAny, /*MI*/0, /*Op*/0, /*SizeInBits*/32,
// CHECK-NEXT: GIM_RootCheckRegBankForClass, /*Op*/0, /*RC*/GIMT_Encode2(MyTarget::GPR32RegClassID),
// CHECK-NEXT: // MIs[0] Operand 1
// CHECK-NEXT: // No operand predicates
// CHECK-NEXT: // (frameindex:{ *:[i32] }):$fi => (ADDI:{ *:[i32] } (to_tframeindex:{ *:[i32] } ?:{ *:[i32] }:$fi), 0:{ *:[i32] })
// CHECK-NEXT: GIR_BuildRootMI, /*Opcode*/GIMT_Encode2(MyTarget::ADDI),
// CHECK-NEXT: GIR_RootToRootCopy, /*OpIdx*/0, // DstI[dst]
// CHECK-NEXT: GIR_CustomRenderer, /*InsnID*/0, /*OldInsnID*/0, /*Renderer*/GIMT_Encode2(GICR_renderFrameIndex), // fi
// CHECK-NEXT: GIR_AddImm8, /*InsnID*/0, /*Imm*/0,
// CHECK-NEXT: GIR_RootConstrainSelectedInstOperands,
// CHECK-NEXT: // GIR_Coverage, 0,
// CHECK-NEXT: GIR_EraseRootFromParent_Done,
12 changes: 2 additions & 10 deletions llvm/utils/TableGen/GlobalISelEmitter.cpp
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Expand Up @@ -836,19 +836,15 @@ Expected<InstructionMatcher &> GlobalISelEmitter::createAndImportSelDAGMatcher(
assert(SrcGIOrNull &&
"Expected to have already found an equivalent Instruction");
if (SrcGIOrNull->TheDef->getName() == "G_CONSTANT" ||
SrcGIOrNull->TheDef->getName() == "G_FCONSTANT") {
SrcGIOrNull->TheDef->getName() == "G_FCONSTANT" ||
SrcGIOrNull->TheDef->getName() == "G_FRAME_INDEX") {
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@arsenm arsenm Dec 23, 2024

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G_GLOBAL_VALUE should be the same

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@s-barannikov s-barannikov Dec 23, 2024

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I'll add it in a future PR along with a test.

// imm/fpimm still have operands but we don't need to do anything with it
// here since we don't support ImmLeaf predicates yet. However, we still
// need to note the hidden operand to get GIM_CheckNumOperands correct.
InsnMatcher.addOperand(OpIdx++, "", TempOpIdx);
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.
Expand Down Expand Up @@ -1248,10 +1244,6 @@ Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderer(
DstMIBuilder.addRenderer<CopyRenderer>(Dst.getName());
return InsertPt;
}
if (Dst.getOperator()->getName() == "tframeindex") {
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@arsenm arsenm Dec 23, 2024

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This should be the same as the time case above?

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@s-barannikov s-barannikov Dec 23, 2024 •
edited
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I'm not sure. Technically, yes, it would match the behavior of SelectionDAG.
On the other hand, there is no strict equivalent of frameindex / tframeindex in GISel. There is just one G_FRAME_INDEX, which behaves more like G_CONSTANT in that it is a separate instruction rather than just a flavor of machine operand. The same is true for G_GLOBAL_VALUE, G_CONSTANT_POOL, maybe some others.

Adding CopyRenderer is the default behavior that should be taken if the node doesn't require a special treatment. That is, the check above and the removed check are just whitelisting supported leaf-like nodes. So, if we want to allow this node, the check should be kept. If we want to make it clear that the node is unsupported, it should be removed. I have no strong preference.

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@arsenm arsenm Dec 23, 2024

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In principle we could have G_ pseudos that have a direct inline frame index, which would be the equivalent of TargetFrameIndex. I think we should treat timm/tfpimm/tframeindex consistently here, and pass them through as-is

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@s-barannikov s-barannikov Dec 23, 2024 •
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OK, considering there are other t* nodes, I'll just remove the check and add CopyRenderer unconditionally. There is no good reason to treat tframeindex differently from other t* nodes, and whitelisting them isn't a scalable approach.

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@s-barannikov s-barannikov Dec 23, 2024

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Nah, this needs some larger refactoring. Will do it in a separate PR.
I'll restore the check for now.

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There aren't that many of these, and they are kind of a special case. It's only the constant-like opcodes have target equivalents

DstMIBuilder.addRenderer<CopyRenderer>(Dst.getName());
return InsertPt;
}
if (Dst.getOperator()->getName() == "imm") {
DstMIBuilder.addRenderer<CopyConstantAsImmRenderer>(Dst.getName());
return InsertPt;
Expand Down
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