Patchwork [02/13] tcg: add tcg_reg_sync()

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Submitter Aurelien Jarno
Date Sept. 27, 2012, 5:15 p.m.
Message ID <1348766113-18373-3-git-send-email-aurelien@aurel32.net>
Download mbox | patch
Permalink /patch/187438/
State New
Headers show

Comments

Aurelien Jarno - Sept. 27, 2012, 5:15 p.m.
Add a new function tcg_reg_sync() to synchronize the canonical location
of a temp with the value in the associated register, but without freeing
it. Rewrite tcg_reg_free() to first call tcg_reg_sync() and then to free
the register.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 tcg/tcg.c |   29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)
Richard Henderson - Sept. 27, 2012, 6:24 p.m.
On 09/27/2012 10:15 AM, Aurelien Jarno wrote:
> Add a new function tcg_reg_sync() to synchronize the canonical location
> of a temp with the value in the associated register, but without freeing
> it. Rewrite tcg_reg_free() to first call tcg_reg_sync() and then to free
> the register.
> 
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

Reviewed-by: Richard Henderson <rth@twiddle.net>

> +/* sync register 'reg' by saving it to the corresponding temporary */
> +static inline void tcg_reg_sync(TCGContext *s, int reg)

Isn't the compiler good enough at deciding inlining?


r~
Aurelien Jarno - Sept. 27, 2012, 8 p.m.
On Thu, Sep 27, 2012 at 11:24:34AM -0700, Richard Henderson wrote:
> On 09/27/2012 10:15 AM, Aurelien Jarno wrote:
> > Add a new function tcg_reg_sync() to synchronize the canonical location
> > of a temp with the value in the associated register, but without freeing
> > it. Rewrite tcg_reg_free() to first call tcg_reg_sync() and then to free
> > the register.
> > 
> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> 
> Reviewed-by: Richard Henderson <rth@twiddle.net>
> 
> > +/* sync register 'reg' by saving it to the corresponding temporary */
> > +static inline void tcg_reg_sync(TCGContext *s, int reg)
> 
> Isn't the compiler good enough at deciding inlining?
> 

Surprisingly the compiler doesn't inline that many things. For example
all the tcg_reg_alloc_* functions are used only once, but are not
inlined.

Patch

diff --git a/tcg/tcg.c b/tcg/tcg.c
index c739a3b..2ac7097 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1469,22 +1469,33 @@  static void temp_allocate_frame(TCGContext *s, int temp)
     s->current_frame_offset += (tcg_target_long)sizeof(tcg_target_long);
 }
 
+/* sync register 'reg' by saving it to the corresponding temporary */
+static inline void tcg_reg_sync(TCGContext *s, int reg)
+{
+    TCGTemp *ts;
+    int temp;
+
+    temp = s->reg_to_temp[reg];
+    ts = &s->temps[temp];
+    assert(ts->val_type == TEMP_VAL_REG);
+    if (!ts->mem_coherent && !ts->fixed_reg) {
+        if (!ts->mem_allocated) {
+            temp_allocate_frame(s, temp);
+        }
+        tcg_out_st(s, ts->type, reg, ts->mem_reg, ts->mem_offset);
+    }
+    ts->mem_coherent = 1;
+}
+
 /* free register 'reg' by spilling the corresponding temporary if necessary */
 static void tcg_reg_free(TCGContext *s, int reg)
 {
-    TCGTemp *ts;
     int temp;
 
     temp = s->reg_to_temp[reg];
     if (temp != -1) {
-        ts = &s->temps[temp];
-        assert(ts->val_type == TEMP_VAL_REG);
-        if (!ts->mem_coherent) {
-            if (!ts->mem_allocated) 
-                temp_allocate_frame(s, temp);
-            tcg_out_st(s, ts->type, reg, ts->mem_reg, ts->mem_offset);
-        }
-        ts->val_type = TEMP_VAL_MEM;
+        tcg_reg_sync(s, reg);
+        s->temps[temp].val_type = TEMP_VAL_MEM;
         s->reg_to_temp[reg] = -1;
     }
 }