MIPS: Emulate the new MIPS R6 B{L,G}Ε{Z,}{AL,}C instructions

[uclinux-h8/linux.git] / arch / mips / math-emu / cp1emu.c

diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 798204e..c770617 100644 (file)
--- 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 +