diff options
| author |   Markos Chandras <markos.chandras@imgtec.com> | 2014-11-26 13:05:09 +0000 |
|---|---|---|
| committer | Markos Chandras <markos.chandras@imgtec.com> | 2015-02-17 15:37:33 +0000 |
| commit | f1b44067c19258b7614e3cd09dfe8d8e12ff5895 (patch) | |
| tree | eb23ac6695fecc5d565e3c21106ead25d9e672ea /arch/mips/math-emu | |
| parent | MIPS: Emulate the new MIPS R6 B{L,G}Ε{Z,}{AL,}C instructions (diff) | |
| download | linux-dev-f1b44067c19258b7614e3cd09dfe8d8e12ff5895.tar.xz linux-dev-f1b44067c19258b7614e3cd09dfe8d8e12ff5895.zip | |
MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructions
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
BGTZALC: Compact branch-and-link if GPR rt is > to zero
BLTZL : Compact branch if GPR rt is < to zero
BGTZL : Compact branch if GPR rt is > to zero
BLTC : Compact branch if GPR rs is less than GPR rt
BLTUC : Similar to BLTC but unsigned
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Diffstat (limited to 'arch/mips/math-emu')
| -rw-r--r-- | arch/mips/math-emu/cp1emu.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index c770617dc340..d6d67e2a0434 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -589,6 +589,31 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, if (NO_R6EMU) break; case bgtz_op: + /* + * Compact branches for R6 for the + * bgtz and bgtzl opcodes. + * BGTZ | rs = 0 | rt != 0 == BGTZALC + * BGTZ | rs = rt != 0 == BLTZALC + * BGTZ | rs != 0 | rt != 0 == BLTUC + * BGTZL | rs = 0 | rt != 0 == BGTZC + * BGTZL | rs = rt != 0 == BLTZC + * BGTZL | rs != 0 | rt != 0 == BLTC + * + * *ZALC varint for BGTZ &&& rt != 0 + * For real GTZ{,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 + |