9375962ac9
The vast majority of the following (very common) opcodes were always called with identical arguments: - `GIM_CheckType` for the root - `GIM_CheckRegBankForClass` for the root - `GIR_Copy` between the old and new root - `GIR_ConstrainSelectedInstOperands` on the new root - `GIR_BuildMI` to create the new root I added overloaded version of each opcode specialized for the root instructions. It always saves between 1 and 2 bytes per instance depending on the number of arguments specialized into the opcode. Some of these opcodes had between 5 and 15k occurences in the AArch64 GlobalISel Match Table. Additionally, the following opcodes are almost always used in the same sequence: - `GIR_EraseFromParent 0` + `GIR_Done` - `GIR_EraseRootFromParent_Done` has been created to do both. Saves 2 bytes per occurence. - `GIR_IsSafeToFold` was *always* called for each InsnID except 0. - Changed the opcode to take the number of instructions to check after `MI[0]` The savings from these are pretty neat. For `AArch64GenGlobalISel.inc`: - `AArch64InstructionSelector.cpp.o` goes down from 772kb to 704kb (-10% code size) - Self-reported MatchTable size goes from 420380 bytes to 352426 bytes (~ -17%) A smaller match table means a faster match table because we spend less time iterating and decoding. I don't have a solid measurement methodology for GlobalISel performance so I don't have precise numbers but I saw a few % of improvements in a simple testcase.
23 lines
1.1 KiB
TableGen
23 lines
1.1 KiB
TableGen
// RUN: llvm-tblgen -gen-global-isel -optimize-match-table=false -I %p/Common -I %p/../../include %s -o - < %s | FileCheck -check-prefix=GISEL %s
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include "llvm/Target/Target.td"
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include "GlobalISelEmitterCommon.td"
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let TargetPrefix = "mytarget" in {
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def int_mytarget_sleep0 : Intrinsic<[], [llvm_i32_ty], [ImmArg<ArgIndex<0>>]>;
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}
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// GISEL: GIM_CheckOpcode, /*MI*/0, GIMT_Encode2(TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS),
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// GISEL-NEXT: // MIs[0] Operand 0
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// GISEL-NEXT: GIM_CheckIntrinsicID, /*MI*/0, /*Op*/0, GIMT_Encode2(Intrinsic::mytarget_sleep0),
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// GISEL-NEXT: // MIs[0] src
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// GISEL-NEXT: GIM_CheckIsImm, /*MI*/0, /*Op*/1,
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// GISEL-NEXT: GIM_CheckImmOperandPredicate, /*MI*/0, /*MO*/1, /*Predicate*/GIMT_Encode2(GICXXPred_I64_Predicate_tuimm9),
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// GISEL-NEXT: // (intrinsic_void {{[0-9]+}}:{ *:[iPTR] }, (timm:{ *:[i32] })<<P:Predicate_tuimm9>>:$src) => (SLEEP0 (timm:{ *:[i32] }):$src)
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// GISEL-NEXT: GIR_BuildRootMI, /*Opcode*/GIMT_Encode2(MyTarget::SLEEP0),
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// GISEL-NEXT: GIR_RootToRootCopy, /*OpIdx*/1, // src
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def tuimm9 : TImmLeaf<i32, [{ return isUInt<9>(Imm); }]>;
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def SLEEP0 : I<(outs), (ins i32imm:$src),
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[(int_mytarget_sleep0 tuimm9:$src)]
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>;
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