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author | Richard Henderson <rth@twiddle.net> | 2016-06-23 20:34:22 -0700 |
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committer | Richard Henderson <rth@twiddle.net> | 2016-08-05 21:44:40 +0530 |
commit | c70fbf0a9938baf3b4f843355a77c17a7e945b98 (patch) | |
tree | 36d35646400d8c28d0501dd44ef4b154c23be5f1 /tcg/tcg.c | |
parent | bee158cb4dde35c41632a3a129c869f14a32f8f0 (diff) | |
download | qemu-c70fbf0a9938baf3b4f843355a77c17a7e945b98.zip qemu-c70fbf0a9938baf3b4f843355a77c17a7e945b98.tar.gz qemu-c70fbf0a9938baf3b4f843355a77c17a7e945b98.tar.bz2 |
tcg: Compress dead_temps and mem_temps into a single array
We only need two bits per temporary. Fold the two bytes into one,
and reduce the memory and cachelines required during compilation.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg/tcg.c')
-rw-r--r-- | tcg/tcg.c | 119 |
1 files changed, 60 insertions, 59 deletions
@@ -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]; @@ -1312,27 +1312,29 @@ void tcg_op_remove(TCGContext *s, TCGOp *op) } #ifdef USE_LIVENESS_ANALYSIS + +#define TS_DEAD 1 +#define TS_MEM 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_MEM, 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_MEM; + } } } @@ -1341,12 +1343,12 @@ 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; @@ -1375,7 +1377,7 @@ 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; } } @@ -1386,39 +1388,41 @@ 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_MEM) { 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_MEM, 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_MEM; + } } /* 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; + } } } } @@ -1427,8 +1431,7 @@ 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: @@ -1449,8 +1452,8 @@ 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, @@ -1487,8 +1490,8 @@ 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; } @@ -1496,8 +1499,7 @@ 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]; @@ -1520,8 +1522,7 @@ 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; } } @@ -1532,35 +1533,35 @@ 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_MEM) { 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_MEM; + } } /* 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; |