RE: [RFC PATCH v3 28/34] Hexagon (target/hexagon) TCG generation helpers

[Taylor Simpson]

> -----Original Message-----
> From: Richard Henderson <richard.henderson@linaro.org>
> Sent: Friday, August 28, 2020 7:49 PM
> To: Taylor Simpson <tsimpson@quicinc.com>; qemu-devel@nongnu.org
> Cc: philmd@redhat.com; laurent@vivier.eu; riku.voipio@iki.fi;
> aleksandar.m.mail@gmail.com; ale@rev.ng
> Subject: Re: [RFC PATCH v3 28/34] Hexagon (target/hexagon) TCG
> generation helpers
>
> On 8/18/20 8:50 AM, Taylor Simpson wrote:
> > Helpers for reading and writing registers
> > Helpers for load-locked/store-conditional
> >
> > Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
> > ---
> >  target/hexagon/genptr_helpers.h | 244
> ++++++++++++++++++++++++++++++++++++++++
> >  target/hexagon/op_helper.c      |  18 +++
> >  2 files changed, 262 insertions(+)
> >  create mode 100644 target/hexagon/genptr_helpers.h
> >
> > diff --git a/target/hexagon/genptr_helpers.h
> b/target/hexagon/genptr_helpers.h
> > new file mode 100644
> > index 0000000..ffcb1e3
> > --- /dev/null
> > +++ b/target/hexagon/genptr_helpers.h
> > @@ -0,0 +1,244 @@
> > +
> > +static inline void gen_log_reg_write(int rnum, TCGv val, int slot,
> > +                                     int is_predicated)
>
> These are quite large.  Why are they marked inline?

Since this is a header file, it prevents the compiler from complaining when 
they aren't used.

>
> > +        /* Low word */
> > +        tcg_gen_extrl_i64_i32(val32, val);
> > +        tcg_gen_mov_tl(hex_new_value[rnum], val32);
>
> Why are you extracting into a temporary?
> This could be done with
>
>     tcg_gen_extr_i64_i32(hex_new_value[rnum],
>                          hex_new_value[rnum + 1], val);

OK

> > +static inline void gen_read_p3_0(TCGv control_reg)
> > +{
> > +    TCGv pval = tcg_temp_new();
> > +    int i;
> > +    tcg_gen_movi_tl(control_reg, 0);
> > +    for (i = NUM_PREGS - 1; i >= 0; i--) {
> > +        tcg_gen_shli_tl(control_reg, control_reg, 8);
> > +        tcg_gen_andi_tl(pval, hex_pred[i], 0xff);
> > +        tcg_gen_or_tl(control_reg, control_reg, pval);
>
> tcg_gen_deposit_tl(control_reg, control_reg,
>                    hex_pred[i], i * 8, 8);

OK

> > +    for (i = 0; i < NUM_PREGS; i++) {
> > +        tcg_gen_andi_tl(pred_val, control_reg, 0xff);
> > +        tcg_gen_mov_tl(hex_pred[i], pred_val);
> > +        tcg_gen_shri_tl(control_reg, control_reg, 8);
>
> tcg_gen_extract_tl(hex_pred[i], control_reg, i * 8, 8);

OK

> > +static inline void log_store32(CPUHexagonState *env, target_ulong addr,
> > +                               int32_t val, int width, int slot)
> > +{
> > +    HEX_DEBUG_LOG("log_store%d(0x%x, %d [0x%x])\n", width, addr, val,
> val);
> > +    env->mem_log_stores[slot].va = addr;
> > +    env->mem_log_stores[slot].width = width;
> > +    env->mem_log_stores[slot].data32 = val;
> > +}
> > +
> > +static inline void log_store64(CPUHexagonState *env, target_ulong addr,
> > +                               int64_t val, int width, int slot)
> > +{
> > +    HEX_DEBUG_LOG("log_store%d(0x%x, %ld [0x%lx])\n", width, addr,
> val, val);
> > +    env->mem_log_stores[slot].va = addr;
> > +    env->mem_log_stores[slot].width = width;
> > +    env->mem_log_stores[slot].data64 = val;
> > +}
>
> ... or fold this re-addition back into where it was accidentally removed.  ;-)

Could you elaborate?