diff options
| -rw-r--r-- | src/core/arm/interpreter/armemu.cpp | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/src/core/arm/interpreter/armemu.cpp b/src/core/arm/interpreter/armemu.cpp index b21d97e12..7408b6f08 100644 --- a/src/core/arm/interpreter/armemu.cpp +++ b/src/core/arm/interpreter/armemu.cpp @@ -6374,7 +6374,30 @@ L_stm_s_takeabort: printf ("Unhandled v6 insn: smmla/smmls/smmul\n"); break; case 0x78: - printf ("Unhandled v6 insn: usad/usada8\n"); + if (BITS(20, 24) == 0x18) + { + const u8 rm_idx = BITS(8, 11); + const u8 rn_idx = BITS(0, 3); + const u8 rd_idx = BITS(16, 19); + + const u32 rm_val = state->Reg[rm_idx]; + const u32 rn_val = state->Reg[rn_idx]; + + const u8 diff1 = (u8)::abs((rn_val & 0xFF) - (rm_val & 0xFF)); + const u8 diff2 = (u8)::abs(((rn_val >> 8) & 0xFF) - ((rm_val >> 8) & 0xFF)); + const u8 diff3 = (u8)::abs(((rn_val >> 16) & 0xFF) - ((rm_val >> 16) & 0xFF)); + const u8 diff4 = (u8)::abs(((rn_val >> 24) & 0xFF) - ((rm_val >> 24) & 0xFF)); + + u32 finalDif = (diff1 + diff2 + diff3 + diff4); + + // Op is USADA8 if true. + const u8 ra_idx = BITS(12, 15); + if (ra_idx != 15) + finalDif += state->Reg[ra_idx]; + + state->Reg[rd_idx] = finalDif; + return 1; + } break; case 0x7a: printf ("Unhandled v6 insn: usbfx\n"); |