diff options
| author | Alex Barney <thealexbarney@gmail.com> | 2018-10-30 19:43:02 -0600 |
|---|---|---|
| committer | gdkchan <gab.dark.100@gmail.com> | 2018-10-30 22:43:02 -0300 |
| commit | 9cb57fb4bb3bbae0ae052a5af4a96a49fc5d864d (patch) | |
| tree | 0c97425aeb311c142bc92a6fcc503cb2c07d4376 /ChocolArm64/Decoders/DecoderHelper.cs | |
| parent | 5a87e58183578f5b84ca8d01cbb76aed11820f78 (diff) | |
Adjust naming conventions for Ryujinx and ChocolArm64 projects (#484)
* Change naming convention for Ryujinx project
* Change naming convention for ChocolArm64 project
* Fix NaN
* Remove unneeded this. from Ryujinx project
* Adjust naming from new PRs
* Name changes based on feedback
* How did this get removed?
* Rebasing fix
* Change FP enum case
* Remove prefix from ChocolArm64 classes - Part 1
* Remove prefix from ChocolArm64 classes - Part 2
* Fix alignment from last commit's renaming
* Rename namespaces
* Rename stragglers
* Fix alignment
* Rename OpCode class
* Missed a few
* Adjust alignment
Diffstat (limited to 'ChocolArm64/Decoders/DecoderHelper.cs')
| -rw-r--r-- | ChocolArm64/Decoders/DecoderHelper.cs | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/ChocolArm64/Decoders/DecoderHelper.cs b/ChocolArm64/Decoders/DecoderHelper.cs new file mode 100644 index 00000000..6ee279d7 --- /dev/null +++ b/ChocolArm64/Decoders/DecoderHelper.cs @@ -0,0 +1,107 @@ +using System; + +namespace ChocolArm64.Decoders +{ + static class DecoderHelper + { + public struct BitMask + { + public long WMask; + public long TMask; + public int Pos; + public int Shift; + public bool IsUndefined; + + public static BitMask Invalid => new BitMask { IsUndefined = true }; + } + + public static BitMask DecodeBitMask(int opCode, bool immediate) + { + int immS = (opCode >> 10) & 0x3f; + int immR = (opCode >> 16) & 0x3f; + + int n = (opCode >> 22) & 1; + int sf = (opCode >> 31) & 1; + + int length = BitUtils.HighestBitSet32((~immS & 0x3f) | (n << 6)); + + if (length < 1 || (sf == 0 && n != 0)) + { + return BitMask.Invalid; + } + + int size = 1 << length; + + int levels = size - 1; + + int s = immS & levels; + int r = immR & levels; + + if (immediate && s == levels) + { + return BitMask.Invalid; + } + + long wMask = BitUtils.FillWithOnes(s + 1); + long tMask = BitUtils.FillWithOnes(((s - r) & levels) + 1); + + if (r > 0) + { + wMask = BitUtils.RotateRight(wMask, r, size); + wMask &= BitUtils.FillWithOnes(size); + } + + return new BitMask() + { + WMask = BitUtils.Replicate(wMask, size), + TMask = BitUtils.Replicate(tMask, size), + + Pos = immS, + Shift = immR + }; + } + + public static long DecodeImm8Float(long imm, int size) + { + int e = 0, f = 0; + + switch (size) + { + case 0: e = 8; f = 23; break; + case 1: e = 11; f = 52; break; + + default: throw new ArgumentOutOfRangeException(nameof(size)); + } + + long value = (imm & 0x3f) << f - 4; + + long eBit = (imm >> 6) & 1; + long sBit = (imm >> 7) & 1; + + if (eBit != 0) + { + value |= (1L << e - 3) - 1 << f + 2; + } + + value |= (eBit ^ 1) << f + e - 1; + value |= sBit << f + e; + + return value; + } + + public static long DecodeImm26_2(int opCode) + { + return ((long)opCode << 38) >> 36; + } + + public static long DecodeImmS19_2(int opCode) + { + return (((long)opCode << 40) >> 43) & ~3; + } + + public static long DecodeImmS14_2(int opCode) + { + return (((long)opCode << 45) >> 48) & ~3; + } + } +}
\ No newline at end of file |
