clo and clz

dc615639 · George Hotz · eb2d5789 · dc615639
Commit dc615639 authored Sep 30, 2021 by George Hotz
Hide whitespace changes
Inline Side-by-side

Showing with 4 additions and 0 deletions

MIPS.sol contracts/MIPS.sol +4 -0

No files found.
--- a/contracts/MIPS.sol
+++ b/contracts/MIPS.sol
@@ -245,6 +245,10 @@ contract MIPS {
    } else if (opcode == 0xf) { return rt<<16; // lui
    } else if (opcode == 0x1c) {  // SPECIAL2
      if (func == 2) return uint32(int32(rs)*int32(rt)); // mul
+      if (func == 0x20 || func == 0x21) { // clo
+        if (func == 0x20) rs = ~rs;
+        uint32 i = 0; while (rs&0x80000000 != 0) { i++; rs <<= 1; } return i;
+      }
    } else if (opcode == 0x20) {  // lb
      return SE((mem >> (24-(rs&3)*8)) & 0xFF, 8);
    } else if (opcode == 0x21) {  // lh