[PATCH 14/27] tcg: Don't re-use TEMP_TB temporaries

From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, cota@braap.org
Subject: [PATCH 14/27] tcg: Don't re-use TEMP_TB temporaries
Date: Mon, 30 Jan 2023 10:59:22 -1000	[thread overview]
Message-ID: <20230130205935.1157347-16-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230130205935.1157347-1-richard.henderson@linaro.org>

Reusing TEMP_TB interferes with detecting whether the
temp can be adjusted to TEMP_EBB.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/tcg/tcg.h |   2 +-
 tcg/tcg.c         | 101 ++++++++++++++++++++++++----------------------
 2 files changed, 53 insertions(+), 50 deletions(-)

diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index fe57373d4b..0a3d14ce66 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -610,7 +610,7 @@ struct TCGContext {
 #endif
 
     GHashTable *const_table[TCG_TYPE_COUNT];
-    TCGTempSet free_temps[TCG_TYPE_COUNT * 2];
+    TCGTempSet free_temps[TCG_TYPE_COUNT];
     TCGTemp temps[TCG_MAX_TEMPS]; /* globals first, temps after */
 
     QTAILQ_HEAD(, TCGOp) ops, free_ops;
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 73215741d0..1dbba58167 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1258,63 +1258,66 @@ TCGTemp *tcg_global_mem_new_internal(TCGType type, TCGv_ptr base,
 TCGTemp *tcg_temp_new_internal(TCGType type, TCGTempKind kind)
 {
     TCGContext *s = tcg_ctx;
-    bool temp_local = kind == TEMP_TB;
     TCGTemp *ts;
-    int idx, k;
+    int n;
 
-    k = type + (temp_local ? TCG_TYPE_COUNT : 0);
-    idx = find_first_bit(s->free_temps[k].l, TCG_MAX_TEMPS);
-    if (idx < TCG_MAX_TEMPS) {
-        /* There is already an available temp with the right type.  */
-        clear_bit(idx, s->free_temps[k].l);
+    if (kind == TEMP_EBB) {
+        int idx = find_first_bit(s->free_temps[type].l, TCG_MAX_TEMPS);
 
-        ts = &s->temps[idx];
-        ts->temp_allocated = 1;
-        tcg_debug_assert(ts->base_type == type);
-        tcg_debug_assert(ts->kind == kind);
-    } else {
-        int i, n;
+        if (idx < TCG_MAX_TEMPS) {
+            /* There is already an available temp with the right type.  */
+            clear_bit(idx, s->free_temps[type].l);
 
-        switch (type) {
-        case TCG_TYPE_I32:
-        case TCG_TYPE_V64:
-        case TCG_TYPE_V128:
-        case TCG_TYPE_V256:
-            n = 1;
-            break;
-        case TCG_TYPE_I64:
-            n = 64 / TCG_TARGET_REG_BITS;
-            break;
-        case TCG_TYPE_I128:
-            n = 128 / TCG_TARGET_REG_BITS;
-            break;
-        default:
-            g_assert_not_reached();
+            ts = &s->temps[idx];
+            ts->temp_allocated = 1;
+            tcg_debug_assert(ts->base_type == type);
+            tcg_debug_assert(ts->kind == kind);
+            goto done;
         }
+    } else {
+        tcg_debug_assert(kind == TEMP_TB);
+    }
 
-        ts = tcg_temp_alloc(s);
-        ts->base_type = type;
-        ts->temp_allocated = 1;
-        ts->kind = kind;
+    switch (type) {
+    case TCG_TYPE_I32:
+    case TCG_TYPE_V64:
+    case TCG_TYPE_V128:
+    case TCG_TYPE_V256:
+        n = 1;
+        break;
+    case TCG_TYPE_I64:
+        n = 64 / TCG_TARGET_REG_BITS;
+        break;
+    case TCG_TYPE_I128:
+        n = 128 / TCG_TARGET_REG_BITS;
+        break;
+    default:
+        g_assert_not_reached();
+    }
 
-        if (n == 1) {
-            ts->type = type;
-        } else {
-            ts->type = TCG_TYPE_REG;
+    ts = tcg_temp_alloc(s);
+    ts->base_type = type;
+    ts->temp_allocated = 1;
+    ts->kind = kind;
 
-            for (i = 1; i < n; ++i) {
-                TCGTemp *ts2 = tcg_temp_alloc(s);
+    if (n == 1) {
+        ts->type = type;
+    } else {
+        ts->type = TCG_TYPE_REG;
 
-                tcg_debug_assert(ts2 == ts + i);
-                ts2->base_type = type;
-                ts2->type = TCG_TYPE_REG;
-                ts2->temp_allocated = 1;
-                ts2->temp_subindex = i;
-                ts2->kind = kind;
-            }
+        for (int i = 1; i < n; ++i) {
+            TCGTemp *ts2 = tcg_temp_alloc(s);
+
+            tcg_debug_assert(ts2 == ts + i);
+            ts2->base_type = type;
+            ts2->type = TCG_TYPE_REG;
+            ts2->temp_allocated = 1;
+            ts2->temp_subindex = i;
+            ts2->kind = kind;
         }
     }
 
+ done:
 #if defined(CONFIG_DEBUG_TCG)
     s->temps_in_use++;
 #endif
@@ -1359,7 +1362,6 @@ TCGv_vec tcg_temp_new_vec_matching(TCGv_vec match)
 void tcg_temp_free_internal(TCGTemp *ts)
 {
     TCGContext *s = tcg_ctx;
-    int k, idx;
 
     switch (ts->kind) {
     case TEMP_CONST:
@@ -1383,9 +1385,10 @@ void tcg_temp_free_internal(TCGTemp *ts)
     s->temps_in_use--;
 #endif
 
-    idx = temp_idx(ts);
-    k = ts->base_type + (ts->kind == TEMP_EBB ? 0 : TCG_TYPE_COUNT);
-    set_bit(idx, s->free_temps[k].l);
+    if (ts->kind == TEMP_EBB) {
+        int idx = temp_idx(ts);
+        set_bit(idx, s->free_temps[ts->base_type].l);
+    }
 }
 
 TCGTemp *tcg_constant_internal(TCGType type, int64_t val)
-- 
2.34.1


