[v5,04/23] tcg: Add temp_readonly

Commit Message

Richard Henderson Dec. 17, 2020, 2:51 p.m. UTC

In most, but not all, places that we check for TEMP_FIXED,
we are really testing that we do not modify the temporary.

Reviewed-by: Alex Bennée <[e-mail]>
Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>
Signed-off-by: Richard Henderson <[e-mail]>
---
 include/tcg/tcg.h |  5 +++++
 tcg/tcg.c         | 21 ++++++++++-----------
 2 files changed, 15 insertions(+), 11 deletions(-)

Patch

diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index 30bd525d83..9a9ced3b15 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -681,6 +681,11 @@  struct TCGContext {
     target_ulong gen_insn_data[TCG_MAX_INSNS][TARGET_INSN_START_WORDS];
 };
 
+static inline bool temp_readonly(TCGTemp *ts)
+{
+    return ts->kind == TEMP_FIXED;
+}
+
 extern TCGContext tcg_init_ctx;
 extern __thread TCGContext *tcg_ctx;
 extern TCGv_env cpu_env;
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 07a25e59b6..54619c1cbc 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -3200,7 +3200,7 @@  static void temp_load(TCGContext *, TCGTemp *, TCGRegSet, TCGRegSet, TCGRegSet);
    mark it free; otherwise mark it dead.  */
 static void temp_free_or_dead(TCGContext *s, TCGTemp *ts, int free_or_dead)
 {
-    if (ts->kind == TEMP_FIXED) {
+    if (temp_readonly(ts)) {
         return;
     }
     if (ts->val_type == TEMP_VAL_REG) {
@@ -3224,7 +3224,7 @@  static inline void temp_dead(TCGContext *s, TCGTemp *ts)
 static void temp_sync(TCGContext *s, TCGTemp *ts, TCGRegSet allocated_regs,
                       TCGRegSet preferred_regs, int free_or_dead)
 {
-    if (ts->kind == TEMP_FIXED) {
+    if (temp_readonly(ts)) {
         return;
     }
     if (!ts->mem_coherent) {
@@ -3407,8 +3407,7 @@  static void temp_save(TCGContext *s, TCGTemp *ts, TCGRegSet allocated_regs)
 {
     /* The liveness analysis already ensures that globals are back
        in memory. Keep an tcg_debug_assert for safety. */
-    tcg_debug_assert(ts->val_type == TEMP_VAL_MEM
-                     || ts->kind == TEMP_FIXED);
+    tcg_debug_assert(ts->val_type == TEMP_VAL_MEM || temp_readonly(ts));
 }
 
 /* save globals to their canonical location and assume they can be
@@ -3488,7 +3487,7 @@  static void tcg_reg_alloc_do_movi(TCGContext *s, TCGTemp *ots,
                                   TCGRegSet preferred_regs)
 {
     /* ENV should not be modified.  */
-    tcg_debug_assert(ots->kind != TEMP_FIXED);
+    tcg_debug_assert(!temp_readonly(ots));
 
     /* The movi is not explicitly generated here.  */
     if (ots->val_type == TEMP_VAL_REG) {
@@ -3528,7 +3527,7 @@  static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op)
     ts = arg_temp(op->args[1]);
 
     /* ENV should not be modified.  */
-    tcg_debug_assert(ots->kind != TEMP_FIXED);
+    tcg_debug_assert(!temp_readonly(ots));
 
     /* Note that otype != itype for no-op truncation.  */
     otype = ots->type;
@@ -3589,7 +3588,7 @@  static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op)
                  * Store the source register into the destination slot
                  * and leave the destination temp as TEMP_VAL_MEM.
                  */
-                assert(ots->kind != TEMP_FIXED);
+                assert(!temp_readonly(ots));
                 if (!ts->mem_allocated) {
                     temp_allocate_frame(s, ots);
                 }
@@ -3626,7 +3625,7 @@  static void tcg_reg_alloc_dup(TCGContext *s, const TCGOp *op)
     its = arg_temp(op->args[1]);
 
     /* ENV should not be modified.  */
-    tcg_debug_assert(ots->kind != TEMP_FIXED);
+    tcg_debug_assert(!temp_readonly(ots));
 
     itype = its->type;
     vece = TCGOP_VECE(op);
@@ -3858,7 +3857,7 @@  static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
             ts = arg_temp(arg);
 
             /* ENV should not be modified.  */
-            tcg_debug_assert(ts->kind != TEMP_FIXED);
+            tcg_debug_assert(!temp_readonly(ts));
 
             if (arg_ct->oalias && !const_args[arg_ct->alias_index]) {
                 reg = new_args[arg_ct->alias_index];
@@ -3899,7 +3898,7 @@  static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op)
         ts = arg_temp(op->args[i]);
 
         /* ENV should not be modified.  */
-        tcg_debug_assert(ts->kind != TEMP_FIXED);
+        tcg_debug_assert(!temp_readonly(ts));
 
         if (NEED_SYNC_ARG(i)) {
             temp_sync(s, ts, o_allocated_regs, 0, IS_DEAD_ARG(i));
@@ -4031,7 +4030,7 @@  static void tcg_reg_alloc_call(TCGContext *s, TCGOp *op)
         ts = arg_temp(arg);
 
         /* ENV should not be modified.  */
-        tcg_debug_assert(ts->kind != TEMP_FIXED);
+        tcg_debug_assert(!temp_readonly(ts));
 
         reg = tcg_target_call_oarg_regs[i];
         tcg_debug_assert(s->reg_to_temp[reg] == NULL);