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authorRichard Henderson <richard.henderson@linaro.org>2022-03-16 09:34:18 -0700
committerRichard Henderson <richard.henderson@linaro.org>2022-04-20 12:12:47 -0700
commitc74824389e1a56781f947e23da68742e8faeaf77 (patch)
tree20821757f9162e18b2943a4e9872e8522090e276 /tcg/tcg.c
parent55d71e0b784e03dbd15bc13d75af88ed5340fde8 (diff)
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tcg: Fix indirect lowering vs TCG_OPF_COND_BRANCH
With TCG_OPF_COND_BRANCH, we extended the lifetimes of globals across extended basic blocks. This means that the liveness computed in pass 1 does not kill globals in the same way as normal temps. Introduce TYPE_EBB to match this lifetime, so that we get correct register allocation for the temps that we introduce during the indirect lowering pass. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Fixes: b4cb76e6208 ("tcg: Do not kill globals at conditional branches") Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'tcg/tcg.c')
-rw-r--r--tcg/tcg.c34
1 files changed, 27 insertions, 7 deletions
diff --git a/tcg/tcg.c b/tcg/tcg.c
index f854252..f2d9ce1 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1024,9 +1024,18 @@ void tcg_temp_free_internal(TCGTemp *ts)
TCGContext *s = tcg_ctx;
int k, idx;
- /* In order to simplify users of tcg_constant_*, silently ignore free. */
- if (ts->kind == TEMP_CONST) {
+ switch (ts->kind) {
+ case TEMP_CONST:
+ /*
+ * In order to simplify users of tcg_constant_*,
+ * silently ignore free.
+ */
return;
+ case TEMP_NORMAL:
+ case TEMP_LOCAL:
+ break;
+ default:
+ g_assert_not_reached();
}
#if defined(CONFIG_DEBUG_TCG)
@@ -1036,7 +1045,6 @@ void tcg_temp_free_internal(TCGTemp *ts)
}
#endif
- tcg_debug_assert(ts->kind < TEMP_GLOBAL);
tcg_debug_assert(ts->temp_allocated != 0);
ts->temp_allocated = 0;
@@ -1674,6 +1682,7 @@ static void tcg_reg_alloc_start(TCGContext *s)
case TEMP_GLOBAL:
break;
case TEMP_NORMAL:
+ case TEMP_EBB:
val = TEMP_VAL_DEAD;
/* fall through */
case TEMP_LOCAL:
@@ -1701,6 +1710,9 @@ static char *tcg_get_arg_str_ptr(TCGContext *s, char *buf, int buf_size,
case TEMP_LOCAL:
snprintf(buf, buf_size, "loc%d", idx - s->nb_globals);
break;
+ case TEMP_EBB:
+ snprintf(buf, buf_size, "ebb%d", idx - s->nb_globals);
+ break;
case TEMP_NORMAL:
snprintf(buf, buf_size, "tmp%d", idx - s->nb_globals);
break;
@@ -2378,6 +2390,7 @@ static void la_bb_end(TCGContext *s, int ng, int nt)
state = TS_DEAD | TS_MEM;
break;
case TEMP_NORMAL:
+ case TEMP_EBB:
case TEMP_CONST:
state = TS_DEAD;
break;
@@ -2405,8 +2418,9 @@ static void la_global_sync(TCGContext *s, int ng)
}
/*
- * liveness analysis: conditional branch: all temps are dead,
- * globals and local temps should be synced.
+ * liveness analysis: conditional branch: all temps are dead unless
+ * explicitly live-across-conditional-branch, globals and local temps
+ * should be synced.
*/
static void la_bb_sync(TCGContext *s, int ng, int nt)
{
@@ -2427,6 +2441,7 @@ static void la_bb_sync(TCGContext *s, int ng, int nt)
case TEMP_NORMAL:
s->temps[i].state = TS_DEAD;
break;
+ case TEMP_EBB:
case TEMP_CONST:
continue;
default:
@@ -2797,6 +2812,7 @@ static bool liveness_pass_2(TCGContext *s)
TCGTemp *dts = tcg_temp_alloc(s);
dts->type = its->type;
dts->base_type = its->base_type;
+ dts->kind = TEMP_EBB;
its->state_ptr = dts;
} else {
its->state_ptr = NULL;
@@ -3107,6 +3123,7 @@ static void temp_free_or_dead(TCGContext *s, TCGTemp *ts, int free_or_dead)
new_type = TEMP_VAL_MEM;
break;
case TEMP_NORMAL:
+ case TEMP_EBB:
new_type = free_or_dead < 0 ? TEMP_VAL_MEM : TEMP_VAL_DEAD;
break;
case TEMP_CONST:
@@ -3353,6 +3370,7 @@ static void tcg_reg_alloc_bb_end(TCGContext *s, TCGRegSet allocated_regs)
temp_save(s, ts, allocated_regs);
break;
case TEMP_NORMAL:
+ case TEMP_EBB:
/* The liveness analysis already ensures that temps are dead.
Keep an tcg_debug_assert for safety. */
tcg_debug_assert(ts->val_type == TEMP_VAL_DEAD);
@@ -3370,8 +3388,9 @@ static void tcg_reg_alloc_bb_end(TCGContext *s, TCGRegSet allocated_regs)
}
/*
- * At a conditional branch, we assume all temporaries are dead and
- * all globals and local temps are synced to their location.
+ * At a conditional branch, we assume all temporaries are dead unless
+ * explicitly live-across-conditional-branch; all globals and local
+ * temps are synced to their location.
*/
static void tcg_reg_alloc_cbranch(TCGContext *s, TCGRegSet allocated_regs)
{
@@ -3390,6 +3409,7 @@ static void tcg_reg_alloc_cbranch(TCGContext *s, TCGRegSet allocated_regs)
case TEMP_NORMAL:
tcg_debug_assert(ts->val_type == TEMP_VAL_DEAD);
break;
+ case TEMP_EBB:
case TEMP_CONST:
break;
default: