diff options
Diffstat (limited to 'arch/mips/math-emu/cp1emu.c')
| -rw-r--r-- | arch/mips/math-emu/cp1emu.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index 798204e492fc..c770617dc340 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -552,6 +552,30 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, if (NO_R6EMU) break; case blez_op: + + /* + * Compact branches for R6 for the + * blez and blezl opcodes. + * BLEZ | rs = 0 | rt != 0 == BLEZALC + * BLEZ | rs = rt != 0 == BGEZALC + * BLEZ | rs != 0 | rt != 0 == BGEUC + * BLEZL | rs = 0 | rt != 0 == BLEZC + * BLEZL | rs = rt != 0 == BGEZC + * BLEZL | rs != 0 | rt != 0 == BGEC + * + * For real BLEZ{,L}, rt is always 0. + */ + if (cpu_has_mips_r6 && insn.i_format.rt) { + if ((insn.i_format.opcode == blez_op) && + ((!insn.i_format.rs && insn.i_format.rt) || + (insn.i_format.rs == insn.i_format.rt))) + regs->regs[31] = regs->cp0_epc + + dec_insn.pc_inc; + *contpc = regs->cp0_epc + dec_insn.pc_inc + + dec_insn.next_pc_inc; + + return 1; + } if ((long)regs->regs[insn.i_format.rs] <= 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + |