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[Qemu-devel] [PATCH v6 10/50] tcg: Avoid loops against variable bounds
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH v6 10/50] tcg: Avoid loops against variable bounds |
Date: |
Mon, 16 Oct 2017 10:25:29 -0700 |
From: Richard Henderson <address@hidden>
Copy s->nb_globals or s->nb_temps to a local variable for the purposes
of iteration. This should allow the compiler to use low-overhead
looping constructs on some hosts.
Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/tcg.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 719db9f2b6..bb342e06dd 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1166,23 +1166,16 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg
ret,
static void tcg_reg_alloc_start(TCGContext *s)
{
- int i;
+ int i, n;
TCGTemp *ts;
- for(i = 0; i < s->nb_globals; i++) {
+
+ for (i = 0, n = s->nb_globals; i < n; i++) {
ts = &s->temps[i];
- if (ts->fixed_reg) {
- ts->val_type = TEMP_VAL_REG;
- } else {
- ts->val_type = TEMP_VAL_MEM;
- }
+ ts->val_type = (ts->fixed_reg ? TEMP_VAL_REG : TEMP_VAL_MEM);
}
- for(i = s->nb_globals; i < s->nb_temps; i++) {
+ for (n = s->nb_temps; i < n; i++) {
ts = &s->temps[i];
- if (ts->temp_local) {
- ts->val_type = TEMP_VAL_MEM;
- } else {
- ts->val_type = TEMP_VAL_DEAD;
- }
+ ts->val_type = (ts->temp_local ? TEMP_VAL_MEM : TEMP_VAL_DEAD);
ts->mem_allocated = 0;
ts->fixed_reg = 0;
}
@@ -2284,9 +2277,9 @@ static void temp_save(TCGContext *s, TCGTemp *ts,
TCGRegSet allocated_regs)
temporary registers needs to be allocated to store a constant. */
static void save_globals(TCGContext *s, TCGRegSet allocated_regs)
{
- int i;
+ int i, n;
- for (i = 0; i < s->nb_globals; i++) {
+ for (i = 0, n = s->nb_globals; i < n; i++) {
temp_save(s, &s->temps[i], allocated_regs);
}
}
@@ -2296,9 +2289,9 @@ static void save_globals(TCGContext *s, TCGRegSet
allocated_regs)
temporary registers needs to be allocated to store a constant. */
static void sync_globals(TCGContext *s, TCGRegSet allocated_regs)
{
- int i;
+ int i, n;
- for (i = 0; i < s->nb_globals; i++) {
+ for (i = 0, n = s->nb_globals; i < n; i++) {
TCGTemp *ts = &s->temps[i];
tcg_debug_assert(ts->val_type != TEMP_VAL_REG
|| ts->fixed_reg
--
2.13.6
- Re: [Qemu-devel] [PATCH v6 02/50] tcg: Propagate args to op->args in optimizer, (continued)
- [Qemu-devel] [PATCH v6 05/50] tcg: Introduce arg_temp, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 06/50] tcg: Add temp_global bit to TCGTemp, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 07/50] tcg: Return NULL temp for TCG_CALL_DUMMY_ARG, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 08/50] tcg: Introduce temp_arg, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 10/50] tcg: Avoid loops against variable bounds,
Richard Henderson <=
- [Qemu-devel] [PATCH v6 11/50] tcg: Change temp_allocate_frame arg to TCGTemp, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 12/50] tcg: Remove unused TCG_CALL_DUMMY_TCGV, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 09/50] tcg: Use per-temp state data in liveness, Richard Henderson, 2017/10/16
- [Qemu-devel] [PATCH v6 13/50] tcg: Export temp_idx, Richard Henderson, 2017/10/16