MIPS R6 added the following four instructions which share the
BGTZ and BGTZL opcode:
BLTZALC: Compact branch-and-link if GPR rt is < to zero
BGEZALC: Compact branch-and-link if GPR rt is > to zero
BGTZL: Compact branch if GPR rt is < to zero
BGEZL: Compact branch if GPR rt is > to zero
Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
---
arch/mips/kernel/branch.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index 7bc2df026b51..ca102557fa3c 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -648,6 +648,19 @@ int __compute_return_epc_for_insn(struct pt_regs *regs,
ret = -SIGILL;
break;
}
+ /* bgtzalc, bltzalc, bgtzc, bltzc */
+ if (cpu_has_mips_r6) {
+ if (insn.i_format.rt) {
+ if (insn.i_format.opcode == blez_op)
+ if (insn.i_format.rs ==
+ insn.i_format.rt ||
+ !insn.i_format.rs)
+ regs->regs[31] = epc + 4;
+ regs->cp0_epc += 8;
+ break;
+ }
+ }
+
/* rt field assumed to be zero */
if ((long)regs->regs[insn.i_format.rs] > 0) {
epc = epc + 4 + (insn.i_format.simmediate << 2);
--
2.2.0
