[llvm] [RISCV][Disassembler] Use a table to store all the decoder tables and their associated features. NFC (PR #130883)
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 12 09:31:16 PDT 2025
https://github.com/topperc updated https://github.com/llvm/llvm-project/pull/130883
>From d812a58e71ee7ebf82a3f6c5da964bfdaa9dd1af Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Tue, 11 Mar 2025 17:39:09 -0700
Subject: [PATCH 1/2] [RISCV][Disassembler] Use a table to store all the
decoder tables and their associated features. NFC
Replace the macros with a table that we can iterate over. Use a
different table for each possible instrution bitwidth.
---
.../RISCV/Disassembler/RISCVDisassembler.cpp | 169 ++++++++++--------
1 file changed, 99 insertions(+), 70 deletions(-)
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
index de742ac428de2..752aad387c87e 100644
--- a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
+++ b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -620,29 +620,19 @@ void RISCVDisassembler::addSPOperands(MCInst &MI) const {
MI.insert(MI.begin() + i, MCOperand::createReg(RISCV::X2));
}
-#define TRY_TO_DECODE_WITH_ADDITIONAL_OPERATION(FEATURE_CHECKS, DECODER_TABLE, \
- DESC, ADDITIONAL_OPERATION) \
- do { \
- if (FEATURE_CHECKS) { \
- LLVM_DEBUG(dbgs() << "Trying " << DESC << " table:\n"); \
- DecodeStatus Result = \
- decodeInstruction(DECODER_TABLE, MI, Insn, Address, this, STI); \
- if (Result != MCDisassembler::Fail) { \
- ADDITIONAL_OPERATION; \
- return Result; \
- } \
- } \
- } while (false)
-#define TRY_TO_DECODE_AND_ADD_SP(FEATURE_CHECKS, DECODER_TABLE, DESC) \
- TRY_TO_DECODE_WITH_ADDITIONAL_OPERATION(FEATURE_CHECKS, DECODER_TABLE, DESC, \
- addSPOperands(MI))
-#define TRY_TO_DECODE(FEATURE_CHECKS, DECODER_TABLE, DESC) \
- TRY_TO_DECODE_WITH_ADDITIONAL_OPERATION(FEATURE_CHECKS, DECODER_TABLE, DESC, \
- (void)nullptr)
-#define TRY_TO_DECODE_FEATURE(FEATURE, DECODER_TABLE, DESC) \
- TRY_TO_DECODE(STI.hasFeature(FEATURE), DECODER_TABLE, DESC)
-#define TRY_TO_DECODE_FEATURE_ANY(FEATURES, DECODER_TABLE, DESC) \
- TRY_TO_DECODE((STI.getFeatureBits() & (FEATURES)).any(), DECODER_TABLE, DESC)
+namespace {
+
+struct DecoderListEntry {
+ const uint8_t *Table;
+ FeatureBitset RequiredFeatures;
+ const char *Desc;
+
+ bool haveRequiredFeatures(const FeatureBitset &ActiveFeatures) const {
+ return RequiredFeatures.none() || (RequiredFeatures & ActiveFeatures).any();
+ }
+};
+
+} // end anonymous namespace
static constexpr FeatureBitset XCVFeatureGroup = {
RISCV::FeatureVendorXCVbitmanip, RISCV::FeatureVendorXCVelw,
@@ -681,6 +671,31 @@ static constexpr FeatureBitset XTHeadGroup = {
RISCV::FeatureVendorXTHeadMemPair, RISCV::FeatureVendorXTHeadSync,
RISCV::FeatureVendorXTHeadVdot};
+static constexpr DecoderListEntry DecoderList32[]{
+ // Vendor Extensions
+ {DecoderTableXVentana32,
+ {RISCV::FeatureVendorXVentanaCondOps},
+ "XVentanaCondOps"},
+ {DecoderTableXTHead32, XTHeadGroup, "T-Head extensions"},
+ {DecoderTableXSfvector32, XSfVectorGroup, "SiFive vector extensions"},
+ {DecoderTableXSfsystem32, XSfSystemGroup, "SiFive system extensions"},
+ {DecoderTableXSfcease32, {RISCV::FeatureVendorXSfcease}, "SiFive sf.cease"},
+ {DecoderTableXmipslsp32, {RISCV::FeatureVendorXMIPSLSP}, "MIPS mips.lsp"},
+ {DecoderTableXmipscmove32,
+ {RISCV::FeatureVendorXMIPSCMove},
+ "MIPS mips.ccmov"},
+ // Standard Extensions
+ {DecoderTableXCV32, XCVFeatureGroup, "CORE-V extensions"},
+ {DecoderTableXqci32, XqciFeatureGroup, "Qualcomm uC Extensions"},
+ {DecoderTableXRivos32, XRivosFeatureGroup, "Rivos"},
+ {DecoderTable32, {}, "RISCV32"},
+ {DecoderTableRV32GPRPair32, {}, "RV32GPRPair (rv32 and GPR pairs)"},
+ {DecoderTableZfinx32, {}, "Zfinx (Float in Integer)"},
+ {DecoderTableZdinxRV32GPRPair32,
+ {},
+ "ZdinxRV32GPRPair (rv32 and Double in Integer)"},
+};
+
DecodeStatus RISCVDisassembler::getInstruction32(MCInst &MI, uint64_t &Size,
ArrayRef<uint8_t> Bytes,
uint64_t Address,
@@ -693,37 +708,40 @@ DecodeStatus RISCVDisassembler::getInstruction32(MCInst &MI, uint64_t &Size,
uint32_t Insn = support::endian::read32le(Bytes.data());
- TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXVentanaCondOps,
- DecoderTableXVentana32, "XVentanaCondOps");
- TRY_TO_DECODE_FEATURE_ANY(XTHeadGroup, DecoderTableXTHead32,
- "T-Head extensions");
- TRY_TO_DECODE_FEATURE_ANY(XSfVectorGroup, DecoderTableXSfvector32,
- "SiFive vector extensions");
- TRY_TO_DECODE_FEATURE_ANY(XSfSystemGroup, DecoderTableXSfsystem32,
- "SiFive system extensions");
- TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXSfcease, DecoderTableXSfcease32,
- "SiFive sf.cease");
- TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXMIPSLSP, DecoderTableXmipslsp32,
- "MIPS mips.lsp");
- TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXMIPSCMove,
- DecoderTableXmipscmove32, "MIPS mips.ccmov");
- TRY_TO_DECODE_FEATURE_ANY(XCVFeatureGroup, DecoderTableXCV32,
- "CORE-V extensions");
- TRY_TO_DECODE_FEATURE_ANY(XqciFeatureGroup, DecoderTableXqci32,
- "Qualcomm uC Extensions");
-
- TRY_TO_DECODE_FEATURE_ANY(XRivosFeatureGroup, DecoderTableXRivos32, "Rivos");
-
- TRY_TO_DECODE(true, DecoderTable32, "RISCV32");
- TRY_TO_DECODE(true, DecoderTableRV32GPRPair32,
- "RV32GPRPair (rv32 and GPR pairs)");
- TRY_TO_DECODE(true, DecoderTableZfinx32, "Zfinx (Float in Integer)");
- TRY_TO_DECODE(true, DecoderTableZdinxRV32GPRPair32,
- "ZdinxRV32GPRPair (rv32 and Double in Integer)");
+ for (const DecoderListEntry &Entry : DecoderList32) {
+ if (!Entry.haveRequiredFeatures(STI.getFeatureBits()))
+ continue;
+
+ LLVM_DEBUG(dbgs() << "Trying " << Entry.Desc << "table:\n");
+ DecodeStatus Result =
+ decodeInstruction(Entry.Table, MI, Insn, Address, this, STI);
+ if (Result == MCDisassembler::Fail)
+ continue;
+
+ return Result;
+ }
return MCDisassembler::Fail;
}
+static constexpr DecoderListEntry DecoderList16[]{
+ // Vendor Extensions
+ {DecoderTableXqci16, XqciFeatureGroup, "Qualcomm uC 16bit"},
+ {DecoderTableXqccmp16,
+ {RISCV::FeatureVendorXqccmp},
+ "Xqccmp (Qualcomm 16-bit Push/Pop & Double Move Instructions)"},
+ {DecoderTableXwchc16, {RISCV::FeatureVendorXwchc}, "WCH QingKe XW"},
+ // Standard Extensions
+ // DecoderTableZicfiss16 must be checked before DecoderTable16.
+ {DecoderTableZicfiss16, {}, "RVZicfiss (Shadow Stack)"},
+ {DecoderTable16, {}, "RISCV_C (16-bit Instruction)"},
+ {DecoderTableRISCV32Only_16, {}, "RISCV32Only_16 (16-bit Instruction)"},
+ // Zc* instructions incompatible with Zcf or Zcd
+ {DecoderTableZcOverlap16,
+ {},
+ "ZcOverlap (16-bit Instructions overlapping with Zcf/Zcd)"},
+};
+
DecodeStatus RISCVDisassembler::getInstruction16(MCInst &MI, uint64_t &Size,
ArrayRef<uint8_t> Bytes,
uint64_t Address,
@@ -736,27 +754,28 @@ DecodeStatus RISCVDisassembler::getInstruction16(MCInst &MI, uint64_t &Size,
uint32_t Insn = support::endian::read16le(Bytes.data());
- TRY_TO_DECODE_FEATURE_ANY(XqciFeatureGroup, DecoderTableXqci16,
- "Qualcomm uC 16bit");
- TRY_TO_DECODE_FEATURE(
- RISCV::FeatureVendorXqccmp, DecoderTableXqccmp16,
- "Xqccmp (Qualcomm 16-bit Push/Pop & Double Move Instructions)");
- TRY_TO_DECODE_AND_ADD_SP(STI.hasFeature(RISCV::FeatureVendorXwchc),
- DecoderTableXwchc16, "WCH QingKe XW");
-
- // DecoderTableZicfiss16 must be checked before DecoderTable16.
- TRY_TO_DECODE(true, DecoderTableZicfiss16, "RVZicfiss (Shadow Stack)");
- TRY_TO_DECODE_AND_ADD_SP(true, DecoderTable16,
- "RISCV_C (16-bit Instruction)");
- TRY_TO_DECODE_AND_ADD_SP(true, DecoderTableRISCV32Only_16,
- "RISCV32Only_16 (16-bit Instruction)");
- // Zc* instructions incompatible with Zcf or Zcd.
- TRY_TO_DECODE(true, DecoderTableZcOverlap16,
- "ZcOverlap (16-bit Instructions overlapping with Zcf/Zcd)");
+ for (const DecoderListEntry &Entry : DecoderList16) {
+ if (!Entry.haveRequiredFeatures(STI.getFeatureBits()))
+ continue;
+
+ LLVM_DEBUG(dbgs() << "Trying " << Entry.Desc << "table:\n");
+ DecodeStatus Result =
+ decodeInstruction(Entry.Table, MI, Insn, Address, this, STI);
+ if (Result == MCDisassembler::Fail)
+ continue;
+
+ addSPOperands(MI);
+
+ return Result;
+ }
return MCDisassembler::Fail;
}
+static constexpr DecoderListEntry DecoderList48[]{
+ {DecoderTableXqci48, XqciFeatureGroup, "Qualcomm uC 48bit"},
+};
+
DecodeStatus RISCVDisassembler::getInstruction48(MCInst &MI, uint64_t &Size,
ArrayRef<uint8_t> Bytes,
uint64_t Address,
@@ -768,11 +787,21 @@ DecodeStatus RISCVDisassembler::getInstruction48(MCInst &MI, uint64_t &Size,
Size = 6;
uint64_t Insn = 0;
- for (size_t i = Size; i-- != 0;) {
+ for (size_t i = Size; i-- != 0;)
Insn += (static_cast<uint64_t>(Bytes[i]) << 8 * i);
+
+ for (const DecoderListEntry &Entry : DecoderList48) {
+ if (!Entry.haveRequiredFeatures(STI.getFeatureBits()))
+ continue;
+
+ LLVM_DEBUG(dbgs() << "Trying " << Entry.Desc << "table:\n");
+ DecodeStatus Result =
+ decodeInstruction(Entry.Table, MI, Insn, Address, this, STI);
+ if (Result == MCDisassembler::Fail)
+ continue;
+
+ return Result;
}
- TRY_TO_DECODE_FEATURE_ANY(XqciFeatureGroup, DecoderTableXqci48,
- "Qualcomm uC 48bit");
return MCDisassembler::Fail;
}
>From 6c64eb93245ad87092ada4b6d242f7ed2f2017c8 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Wed, 12 Mar 2025 09:30:43 -0700
Subject: [PATCH 2/2] fixup! Required->Contained
---
.../Target/RISCV/Disassembler/RISCVDisassembler.cpp | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
index 752aad387c87e..505eb989186c7 100644
--- a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
+++ b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -624,11 +624,12 @@ namespace {
struct DecoderListEntry {
const uint8_t *Table;
- FeatureBitset RequiredFeatures;
+ FeatureBitset ContainedFeatures;
const char *Desc;
- bool haveRequiredFeatures(const FeatureBitset &ActiveFeatures) const {
- return RequiredFeatures.none() || (RequiredFeatures & ActiveFeatures).any();
+ bool haveContainedFeatures(const FeatureBitset &ActiveFeatures) const {
+ return ContainedFeatures.none() ||
+ (ContainedFeatures & ActiveFeatures).any();
}
};
@@ -709,7 +710,7 @@ DecodeStatus RISCVDisassembler::getInstruction32(MCInst &MI, uint64_t &Size,
uint32_t Insn = support::endian::read32le(Bytes.data());
for (const DecoderListEntry &Entry : DecoderList32) {
- if (!Entry.haveRequiredFeatures(STI.getFeatureBits()))
+ if (!Entry.haveContainedFeatures(STI.getFeatureBits()))
continue;
LLVM_DEBUG(dbgs() << "Trying " << Entry.Desc << "table:\n");
@@ -755,7 +756,7 @@ DecodeStatus RISCVDisassembler::getInstruction16(MCInst &MI, uint64_t &Size,
uint32_t Insn = support::endian::read16le(Bytes.data());
for (const DecoderListEntry &Entry : DecoderList16) {
- if (!Entry.haveRequiredFeatures(STI.getFeatureBits()))
+ if (!Entry.haveContainedFeatures(STI.getFeatureBits()))
continue;
LLVM_DEBUG(dbgs() << "Trying " << Entry.Desc << "table:\n");
@@ -791,7 +792,7 @@ DecodeStatus RISCVDisassembler::getInstruction48(MCInst &MI, uint64_t &Size,
Insn += (static_cast<uint64_t>(Bytes[i]) << 8 * i);
for (const DecoderListEntry &Entry : DecoderList48) {
- if (!Entry.haveRequiredFeatures(STI.getFeatureBits()))
+ if (!Entry.haveContainedFeatures(STI.getFeatureBits()))
continue;
LLVM_DEBUG(dbgs() << "Trying " << Entry.Desc << "table:\n");
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