search for: crc32q

...rks well for short identifiers. I don't know how the mix of identifier length seen by lldb compares with that seen by llvm/clang; I imagine they're pretty similar. I have to different proposals, and wanted to gauge which would be preferred: 1. Use xxhash instead. 2. Use the Intel native crc32q instruction to process 8 bytes at a time, then fall back to byte at a time. Non sse 4.2 capable processors (either early or non Intel/AMD x86) would use the existing algorithm, or possibly #1 above. For my test, both result in approximately the same # of cycles (within 0.5%). #1 uses 3+% more in...

...tifier length seen by lldb compares with >> that seen by llvm/clang; I imagine they're pretty similar. >> >> I have to different proposals, and wanted to gauge which would be >> preferred: >> >> 1. Use xxhash instead. >> >> 2. Use the Intel native crc32q instruction to process 8 bytes at a time, >> then fall back to byte at a time. Non sse 4.2 capable processors (either >> early or non Intel/AMD x86) would use the existing algorithm, or possibly >> #1 above. >> >> For my test, both result in approximately the same # o...

...ude/llvm/IntrinsicsX86.td Thu May 26 18:13:19 2011 > @@ -948,19 +948,19 @@ > // Miscellaneous > // CRC Instruction > let TargetPrefix = "x86" in { // All intrinsics start with "llvm.x86.". > - def int_x86_sse42_crc32_8 : GCCBuiltin<"__builtin_ia32_crc32qi">, > + def int_x86_sse42_crc32_32_8 : GCCBuiltin<"__builtin_ia32_crc32qi">, > Intrinsic<[llvm_i32_ty], [llvm_i32_ty, llvm_i8_ty], > [IntrNoMem]>; > - def int_x86_sse42_crc32_16 : GCCBuiltin<"__builtin_i...