On Wed, Jul 19, 2017 at 12:27:50PM +0200, Aurelien Jarno wrote:
> On 2017-07-18 12:55, James Hogan wrote:
> > Using MFC0 to read CP0_UserLocal uses tcg_gen_ld32s_tl, however
> > CP0_UserLocal is a target_ulong. On a big endian host with a MIPS64
> > target this reads and sign extends the more significant half of the
> > 64-bit register.
> >
> > Fix this by using ld_tl to load the whole target_ulong and ext32s_tl to
> > sign extend it, as done for various other target_ulong COP0 registers.
> >
> > Fixes: d279279e2b5c ("target-mips: implement UserLocal Register")
> > Signed-off-by: James Hogan <[email protected]>
> > Cc: Yongbok Kim <[email protected]>
> > Cc: Aurelien Jarno <[email protected]>
> > Cc: Petar Jovanovic <[email protected]>
> > ---
> > Changes in v2:
> > - New patch.
> > ---
> > target/mips/translate.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/target/mips/translate.c b/target/mips/translate.c
> > index 3022f349cb2a..556aba969a12 100644
> > --- a/target/mips/translate.c
> > +++ b/target/mips/translate.c
> > @@ -5138,8 +5138,9 @@ static void gen_mfc0(DisasContext *ctx, TCGv arg, int
> > reg, int sel)
> > goto cp0_unimplemented;
> > case 2:
> > CP0_CHECK(ctx->ulri);
> > - tcg_gen_ld32s_tl(arg, cpu_env,
> > - offsetof(CPUMIPSState,
> > active_tc.CP0_UserLocal));
> > + tcg_gen_ld_tl(arg, cpu_env,
> > + offsetof(CPUMIPSState, active_tc.CP0_UserLocal));
> > + tcg_gen_ext32s_tl(arg, arg);
> > rn = "UserLocal";
> > break;
> > default:
>
> I think this is what gen_mfc0_load64() does, that said this whole areaAh yes, that could do with some wider use (and possibly s/64/tl/ or something). > probably need a rework (see for example how inefficiently > gen_mfc0_load32 is implemented). So: Erm, doesn't gen_mfc0_load32() fail to sign extend as it should when used for mfc0...? > > Reviewed-by: Aurelien Jarno <[email protected]> Cheers James
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