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Re: [Qemu-devel] [PATCH 4/5] tcg: Optimize movcond for constant comparis
From: |
Aurelien Jarno |
Subject: |
Re: [Qemu-devel] [PATCH 4/5] tcg: Optimize movcond for constant comparisons |
Date: |
Fri, 21 Sep 2012 00:04:19 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Tue, Sep 18, 2012 at 11:11:48PM +0200, Aurelien Jarno wrote:
> On Tue, Sep 18, 2012 at 07:23:59AM -0700, Richard Henderson wrote:
> > Signed-off-by: Richard Henderson <address@hidden>
> > ---
> > tcg/optimize.c | 29 +++++++++++++++++++++++++++++
> > 1 file changed, 29 insertions(+)
> >
> > diff --git a/tcg/optimize.c b/tcg/optimize.c
> > index fba0ed9..5b0a8ce 100644
> > --- a/tcg/optimize.c
> > +++ b/tcg/optimize.c
> > @@ -397,6 +397,14 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
> > uint16_t *tcg_opc_ptr,
> > args[3] = tcg_swap_cond(args[3]);
> > }
> > break;
> > + CASE_OP_32_64(movcond):
> > + if (temps[args[1]].state == TCG_TEMP_CONST
> > + && temps[args[2]].state != TCG_TEMP_CONST) {
> > + tmp = args[1];
> > + args[1] = args[2];
> > + args[2] = tmp;
> > + args[5] = tcg_swap_cond(args[5]);
> > + }
> > default:
> > break;
> > }
> > @@ -617,6 +625,27 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
> > uint16_t *tcg_opc_ptr,
> > }
> > args += 4;
> > break;
> > + CASE_OP_33_64(movcond):
> > + if (temps[args[1]].state == TCG_TEMP_CONST
> > + && temps[args[2]].state == TCG_TEMP_CONST) {
> > + gen_opc_buf[op_index] = op_to_mov(op);
> > + tmp = do_constant_folding_cond(op, temps[args[1]].val,
> > + temps[args[2]].val,
> > args[5]);
> > + tcg_opt_gen_mov(s, gen_args, args[0], args[4-tmp],
> > + nb_temps, nb_globals);
> > + gen_args += 2;
> > + } else {
> > + reset_temp(args[0], nb_temps, nb_globals);
> > + gen_args[0] = args[0];
> > + gen_args[1] = args[1];
> > + gen_args[2] = args[2];
> > + gen_args[3] = args[3];
> > + gen_args[4] = args[4];
> > + gen_args[5] = args[5];
> > + gen_args += 6;
> > + }
> > + args += 6;
> > + break;
> > case INDEX_op_call:
> > nb_call_args = (args[0] >> 16) + (args[0] & 0xffff);
> > if (!(args[nb_call_args + 1] & (TCG_CALL_CONST |
> > TCG_CALL_PURE))) {
> > --
> > 1.7.11.4
> >
>
> Reviewed-by: Aurelien Jarno <address@hidden>
Playing a bit more with this patch, I have found it fails when v1 or v2
or constants or copies. The additional patch below fixes the problem.
diff --git a/tcg/optimize.c b/tcg/optimize.c
index f95c511..b7e235e 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -641,12 +641,23 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
uint16_t *tcg_opc_ptr,
CASE_OP_32_64(movcond):
if (temps[args[1]].state == TCG_TEMP_CONST
&& temps[args[2]].state == TCG_TEMP_CONST) {
- gen_opc_buf[op_index] = op_to_mov(op);
tmp = do_constant_folding_cond(op, temps[args[1]].val,
temps[args[2]].val, args[5]);
- tcg_opt_gen_mov(gen_args, args[0], args[4-tmp],
- nb_temps, nb_globals);
- gen_args += 2;
+ if ((temps[args[4-tmp]].state == TCG_TEMP_COPY
+ && temps[args[4-tmp]].val == args[0])
+ || args[0] == args[4-tmp]) {
+ gen_opc_buf[op_index] = INDEX_op_nop;
+ } else if (tmp && temps[args[4-tmp]].state == TCG_TEMP_CONST) {
+ gen_opc_buf[op_index] = op_to_movi(op);
+ tcg_opt_gen_movi(gen_args, args[0], temps[args[4-tmp]].val,
+ nb_temps, nb_globals);
+ gen_args += 2;
+ } else {
+ gen_opc_buf[op_index] = op_to_mov(op);
+ tcg_opt_gen_mov(gen_args, args[0], args[4-tmp],
+ nb_temps, nb_globals);
+ gen_args += 2;
+ }
} else {
reset_temp(args[0], nb_temps, nb_globals);
gen_args[0] = args[0];
--
Aurelien Jarno GPG: 1024D/F1BCDB73
address@hidden http://www.aurel32.net
[Qemu-devel] [PATCH 3/5] tcg-i386: Implement movcond, Richard Henderson, 2012/09/18
[Qemu-devel] [PATCH 2/5] target-alpha: Use movcond, Richard Henderson, 2012/09/18
[Qemu-devel] [PATCH 1/5] tcg: Introduce movcond, Richard Henderson, 2012/09/18
Re: [Qemu-devel] [PATCH 0/5] tcg: movcond, Aurelien Jarno, 2012/09/18