[RISCV] Use uint64_t for Insn in getInstruction32 and getInstruction16. NFC #146619
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…6. NFC Insn is passed to decodeInstruction which is a template function based on the type of Insn. By using uint64_t we ensure only one version of decodeInstruction is created. This reduces the file size of RISCVDisassembler.cpp.o by ~25% in my local build. This should get even more size benefit than llvm#146593.
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@llvm/pr-subscribers-backend-risc-v Author: Craig Topper (topperc) ChangesInsn is passed to decodeInstruction which is a template function based on the type of Insn. By using uint64_t we ensure only one version of decodeInstruction is created. This reduces the file size of RISCVDisassembler.cpp.o by ~25% in my local build. This should get even more size benefit than #146593. Full diff: https://github.com/llvm/llvm-project/pull/146619.diff 1 Files Affected:
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
index 27e04c0cb1f8b..52061e96d0018 100644
--- a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
+++ b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -811,7 +811,9 @@ DecodeStatus RISCVDisassembler::getInstruction32(MCInst &MI, uint64_t &Size,
}
Size = 4;
- uint32_t Insn = support::endian::read32le(Bytes.data());
+ // Use uint64_t to match getInstruction48. decodeInstruction is templated
+ // on the Insn type.
+ uint64_t Insn = support::endian::read32le(Bytes.data());
for (const DecoderListEntry &Entry : DecoderList32) {
if (!Entry.haveContainedFeatures(STI.getFeatureBits()))
@@ -857,7 +859,9 @@ DecodeStatus RISCVDisassembler::getInstruction16(MCInst &MI, uint64_t &Size,
}
Size = 2;
- uint32_t Insn = support::endian::read16le(Bytes.data());
+ // Use uint64_t to match getInstruction48. decodeInstruction is templated
+ // on the Insn type.
+ uint64_t Insn = support::endian::read16le(Bytes.data());
for (const DecoderListEntry &Entry : DecoderList16) {
if (!Entry.haveContainedFeatures(STI.getFeatureBits()))
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jurahul
approved these changes
Jul 2, 2025
lenary
approved these changes
Jul 2, 2025
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Sorry, we didn't consider compiler code size at all when adding the 48-bit instructions. This is a nice improvement. |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/94/builds/8502 Here is the relevant piece of the build log for the reference |
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Insn is passed to decodeInstruction which is a template function based on the type of Insn. By using uint64_t we ensure only one version of decodeInstruction is created. This reduces the file size of RISCVDisassembler.cpp.o by ~25% in my local build.
This should get even more size benefit than #146593.