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authorAlex Barney <thealexbarney@gmail.com>2018-10-30 19:43:02 -0600
committergdkchan <gab.dark.100@gmail.com>2018-10-30 22:43:02 -0300
commit9cb57fb4bb3bbae0ae052a5af4a96a49fc5d864d (patch)
tree0c97425aeb311c142bc92a6fcc503cb2c07d4376 /ChocolArm64/Decoders/DecoderHelper.cs
parent5a87e58183578f5b84ca8d01cbb76aed11820f78 (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.cs107
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