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[Qemu-devel] [PATCH 2/9] tcg/optimizer: check types in copy propagation
From: |
Aurelien Jarno |
Subject: |
[Qemu-devel] [PATCH 2/9] tcg/optimizer: check types in copy propagation |
Date: |
Wed, 19 Sep 2012 22:00:16 +0200 |
The copy propagation doesn't check the types of the temps during copy
propagation. However TCG is using the mov_i32 for the i64 to i32
conversion and thus the two are not equivalent.
With this patch tcg_opt_gen_mov() doesn't consider two temps with
different types as copies anymore.
So far it seems the optimization was not aggressive enough to trigger
this bug, but it will be triggered later in this series once the copy
propagation is improved.
Signed-off-by: Aurelien Jarno <address@hidden>
---
tcg/optimize.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index ca81198..13b5b15 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -106,12 +106,13 @@ static TCGOpcode op_to_movi(TCGOpcode op)
}
}
-static void tcg_opt_gen_mov(TCGArg *gen_args, TCGArg dst, TCGArg src,
- int nb_temps, int nb_globals)
+static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args,
+ TCGArg dst, TCGArg src)
{
- reset_temp(dst, nb_temps, nb_globals);
+ reset_temp(dst, s->nb_temps, s->nb_globals);
assert(temps[src].state != TCG_TEMP_COPY);
- if (src >= nb_globals) {
+ /* Only consider temps with the same type (width) as copies. */
+ if (src >= s->nb_globals && s->temps[dst].type == s->temps[src].type) {
assert(temps[src].state != TCG_TEMP_CONST);
if (temps[src].state != TCG_TEMP_HAS_COPY) {
temps[src].state = TCG_TEMP_HAS_COPY;
@@ -440,8 +441,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t
*tcg_opc_ptr,
gen_opc_buf[op_index] = INDEX_op_nop;
} else {
gen_opc_buf[op_index] = op_to_mov(op);
- tcg_opt_gen_mov(gen_args, args[0], args[1],
- nb_temps, nb_globals);
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
gen_args += 2;
}
args += 3;
@@ -478,8 +478,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t
*tcg_opc_ptr,
gen_opc_buf[op_index] = INDEX_op_nop;
} else {
gen_opc_buf[op_index] = op_to_mov(op);
- tcg_opt_gen_mov(gen_args, args[0], args[1], nb_temps,
- nb_globals);
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
gen_args += 2;
}
args += 3;
@@ -503,8 +502,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t
*tcg_opc_ptr,
break;
}
if (temps[args[1]].state != TCG_TEMP_CONST) {
- tcg_opt_gen_mov(gen_args, args[0], args[1],
- nb_temps, nb_globals);
+ tcg_opt_gen_mov(s, gen_args, args[0], args[1]);
gen_args += 2;
args += 2;
break;
--
1.7.10.4
- [Qemu-devel] [PATCH 0/9] tcg/optimize: rework copy propagation, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 6/9] tcg/optimize: optimize "op r, a, a => movi r, 0", Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 4/9] tcg/optimize: do copy propagation for all operations, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 1/9] tcg/optimizer: remove TCG_TEMP_ANY, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 9/9] tcg: remove #ifdef #endif around TCGOpcode tests, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 2/9] tcg/optimizer: check types in copy propagation,
Aurelien Jarno <=
- [Qemu-devel] [PATCH 7/9] tcg/optimize: further optimize brcond/setcond, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 8/9] tcg/optimize: prefer the "op a, a, b" form for commutative ops, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 3/9] tcg/optimizer: rework copy progagation, Aurelien Jarno, 2012/09/19
- [Qemu-devel] [PATCH 5/9] tcg/optimize: optimize "op r, a, a => mov r, a", Aurelien Jarno, 2012/09/19