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[Qemu-devel] [PATCH 4/4] tcg: Compress dead_temps and mem_temps into a s
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From: |
Richard Henderson |
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Subject: |
[Qemu-devel] [PATCH 4/4] tcg: Compress dead_temps and mem_temps into a single array |
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Date: |
Thu, 23 Jun 2016 11:03:02 -0700 |
We only need two bits per temporary. Fold the two bytes into one,
and reduce the memory and cachelines required during compilation.
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/tcg.c | 119 +++++++++++++++++++++++++++++++-------------------------------
1 file changed, 60 insertions(+), 59 deletions(-)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index b0c9dca..6397a37 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -333,7 +333,7 @@ void tcg_context_init(TCGContext *s)
memset(s, 0, sizeof(*s));
s->nb_globals = 0;
-
+
/* Count total number of arguments and allocate the corresponding
space */
total_args = 0;
@@ -825,16 +825,16 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret,
real_args++;
}
#endif
- /* If stack grows up, then we will be placing successive
- arguments at lower addresses, which means we need to
- reverse the order compared to how we would normally
- treat either big or little-endian. For those arguments
- that will wind up in registers, this still works for
- HPPA (the only current STACK_GROWSUP target) since the
- argument registers are *also* allocated in decreasing
- order. If another such target is added, this logic may
- have to get more complicated to differentiate between
- stack arguments and register arguments. */
+ /* If stack grows up, then we will be placing successive
+ arguments at lower addresses, which means we need to
+ reverse the order compared to how we would normally
+ treat either big or little-endian. For those arguments
+ that will wind up in registers, this still works for
+ HPPA (the only current STACK_GROWSUP target) since the
+ argument registers are *also* allocated in decreasing
+ order. If another such target is added, this logic may
+ have to get more complicated to differentiate between
+ stack arguments and register arguments. */
#if defined(HOST_WORDS_BIGENDIAN) != defined(TCG_TARGET_STACK_GROWSUP)
s->gen_opparam_buf[pi++] = args[i] + 1;
s->gen_opparam_buf[pi++] = args[i];
@@ -1299,27 +1299,29 @@ void tcg_op_remove(TCGContext *s, TCGOp *op)
}
#ifdef USE_LIVENESS_ANALYSIS
+
+#define TS_DEAD 1
+#define TS_SYNC 2
+
/* liveness analysis: end of function: all temps are dead, and globals
should be in memory. */
-static inline void tcg_la_func_end(TCGContext *s, uint8_t *dead_temps,
- uint8_t *mem_temps)
+static inline void tcg_la_func_end(TCGContext *s, uint8_t *temp_state)
{
- memset(dead_temps, 1, s->nb_temps);
- memset(mem_temps, 1, s->nb_globals);
- memset(mem_temps + s->nb_globals, 0, s->nb_temps - s->nb_globals);
+ memset(temp_state, TS_DEAD | TS_SYNC, s->nb_globals);
+ memset(temp_state + s->nb_globals, TS_DEAD, s->nb_temps - s->nb_globals);
}
/* liveness analysis: end of basic block: all temps are dead, globals
and local temps should be in memory. */
-static inline void tcg_la_bb_end(TCGContext *s, uint8_t *dead_temps,
- uint8_t *mem_temps)
+static inline void tcg_la_bb_end(TCGContext *s, uint8_t *temp_state)
{
- int i;
+ int i, n;
- memset(dead_temps, 1, s->nb_temps);
- memset(mem_temps, 1, s->nb_globals);
- for(i = s->nb_globals; i < s->nb_temps; i++) {
- mem_temps[i] = s->temps[i].temp_local;
+ tcg_la_func_end(s, temp_state);
+ for (i = s->nb_globals, n = s->nb_temps; i < n; i++) {
+ if (s->temps[i].temp_local) {
+ temp_state[i] |= TS_SYNC;
+ }
}
}
@@ -1328,12 +1330,12 @@ static inline void tcg_la_bb_end(TCGContext *s, uint8_t
*dead_temps,
temporaries are removed. */
static void tcg_liveness_analysis(TCGContext *s)
{
- uint8_t *dead_temps, *mem_temps;
+ uint8_t *temp_state;
int oi, oi_prev;
+ int nb_globals = s->nb_globals;
- dead_temps = tcg_malloc(s->nb_temps);
- mem_temps = tcg_malloc(s->nb_temps);
- tcg_la_func_end(s, dead_temps, mem_temps);
+ temp_state = tcg_malloc(s->nb_temps);
+ tcg_la_func_end(s, temp_state);
for (oi = s->gen_op_buf[0].prev; oi != 0; oi = oi_prev) {
int i, nb_iargs, nb_oargs;
@@ -1362,7 +1364,7 @@ static void tcg_liveness_analysis(TCGContext *s)
if (call_flags & TCG_CALL_NO_SIDE_EFFECTS) {
for (i = 0; i < nb_oargs; i++) {
arg = args[i];
- if (!dead_temps[arg] || mem_temps[arg]) {
+ if (temp_state[arg] != TS_DEAD) {
goto do_not_remove_call;
}
}
@@ -1373,39 +1375,41 @@ static void tcg_liveness_analysis(TCGContext *s)
/* output args are dead */
for (i = 0; i < nb_oargs; i++) {
arg = args[i];
- if (dead_temps[arg]) {
+ if (temp_state[arg] & TS_DEAD) {
arg_life |= DEAD_ARG << i;
}
- if (mem_temps[arg]) {
+ if (temp_state[arg] & TS_SYNC) {
arg_life |= SYNC_ARG << i;
}
- dead_temps[arg] = 1;
- mem_temps[arg] = 0;
+ temp_state[arg] = TS_DEAD;
}
- if (!(call_flags & TCG_CALL_NO_READ_GLOBALS)) {
- /* globals should be synced to memory */
- memset(mem_temps, 1, s->nb_globals);
- }
if (!(call_flags & (TCG_CALL_NO_WRITE_GLOBALS |
TCG_CALL_NO_READ_GLOBALS))) {
/* globals should go back to memory */
- memset(dead_temps, 1, s->nb_globals);
+ memset(temp_state, TS_DEAD | TS_SYNC, nb_globals);
+ } else if (!(call_flags & TCG_CALL_NO_READ_GLOBALS)) {
+ /* globals should be synced to memory */
+ for (i = 0; i < nb_globals; i++) {
+ temp_state[i] |= TS_SYNC;
+ }
}
/* record arguments that die in this helper */
for (i = nb_oargs; i < nb_iargs + nb_oargs; i++) {
arg = args[i];
if (arg != TCG_CALL_DUMMY_ARG) {
- if (dead_temps[arg]) {
+ if (temp_state[arg] & TS_DEAD) {
arg_life |= DEAD_ARG << i;
}
}
}
/* input arguments are live for preceding opcodes */
- for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
+ for (i = nb_oargs; i < nb_iargs + nb_oargs; i++) {
arg = args[i];
- dead_temps[arg] = 0;
+ if (arg != TCG_CALL_DUMMY_ARG) {
+ temp_state[arg] &= ~TS_DEAD;
+ }
}
}
}
@@ -1414,8 +1418,7 @@ static void tcg_liveness_analysis(TCGContext *s)
break;
case INDEX_op_discard:
/* mark the temporary as dead */
- dead_temps[args[0]] = 1;
- mem_temps[args[0]] = 0;
+ temp_state[args[0]] = TS_DEAD;
break;
case INDEX_op_add2_i32:
@@ -1436,8 +1439,8 @@ static void tcg_liveness_analysis(TCGContext *s)
the low part. The result can be optimized to a simple
add or sub. This happens often for x86_64 guest when the
cpu mode is set to 32 bit. */
- if (dead_temps[args[1]] && !mem_temps[args[1]]) {
- if (dead_temps[args[0]] && !mem_temps[args[0]]) {
+ if (temp_state[args[1]] != TS_DEAD) {
+ if (temp_state[args[0]] != TS_DEAD) {
goto do_remove;
}
/* Replace the opcode and adjust the args in place,
@@ -1474,8 +1477,8 @@ static void tcg_liveness_analysis(TCGContext *s)
do_mul2:
nb_iargs = 2;
nb_oargs = 2;
- if (dead_temps[args[1]] && !mem_temps[args[1]]) {
- if (dead_temps[args[0]] && !mem_temps[args[0]]) {
+ if (temp_state[args[1]] != TS_DEAD) {
+ if (temp_state[args[0]] != TS_DEAD) {
/* Both parts of the operation are dead. */
goto do_remove;
}
@@ -1483,8 +1486,7 @@ static void tcg_liveness_analysis(TCGContext *s)
op->opc = opc = opc_new;
args[1] = args[2];
args[2] = args[3];
- } else if (have_opc_new2 && dead_temps[args[0]]
- && !mem_temps[args[0]]) {
+ } else if (temp_state[args[0]] != TS_DEAD && have_opc_new2) {
/* The low part of the operation is dead; generate the high. */
op->opc = opc = opc_new2;
args[0] = args[1];
@@ -1507,8 +1509,7 @@ static void tcg_liveness_analysis(TCGContext *s)
implies side effects */
if (!(def->flags & TCG_OPF_SIDE_EFFECTS) && nb_oargs != 0) {
for (i = 0; i < nb_oargs; i++) {
- arg = args[i];
- if (!dead_temps[arg] || mem_temps[arg]) {
+ if (temp_state[args[i]] != TS_DEAD) {
goto do_not_remove;
}
}
@@ -1519,35 +1520,35 @@ static void tcg_liveness_analysis(TCGContext *s)
/* output args are dead */
for (i = 0; i < nb_oargs; i++) {
arg = args[i];
- if (dead_temps[arg]) {
+ if (temp_state[arg] & TS_DEAD) {
arg_life |= DEAD_ARG << i;
}
- if (mem_temps[arg]) {
+ if (temp_state[arg] & TS_SYNC) {
arg_life |= SYNC_ARG << i;
}
- dead_temps[arg] = 1;
- mem_temps[arg] = 0;
+ temp_state[arg] = TS_DEAD;
}
/* if end of basic block, update */
if (def->flags & TCG_OPF_BB_END) {
- tcg_la_bb_end(s, dead_temps, mem_temps);
+ tcg_la_bb_end(s, temp_state);
} else if (def->flags & TCG_OPF_SIDE_EFFECTS) {
/* globals should be synced to memory */
- memset(mem_temps, 1, s->nb_globals);
+ for (i = 0; i < nb_globals; i++) {
+ temp_state[i] |= TS_SYNC;
+ }
}
/* record arguments that die in this opcode */
for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
arg = args[i];
- if (dead_temps[arg]) {
+ if (temp_state[arg] & TS_DEAD) {
arg_life |= DEAD_ARG << i;
}
}
/* input arguments are live for preceding opcodes */
for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) {
- arg = args[i];
- dead_temps[arg] = 0;
+ temp_state[args[i]] &= ~TS_DEAD;
}
}
break;
--
2.5.5