Patchwork [4/9] tcg/optimize: do copy propagation for all operations

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Submitter Aurelien Jarno
Date Sept. 19, 2012, 8 p.m.
Message ID <1348084823-18277-5-git-send-email-aurelien@aurel32.net>
Download mbox | patch
Permalink /patch/185209/
State New
Headers show

Comments

Aurelien Jarno - Sept. 19, 2012, 8 p.m.
It is possible to do copy propagation for all operations, even the ones
that have side effects or clobber arguments (it only concerns input
arguments). That said, the call operation should be handled differently
due to the variable number of arguments.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 tcg/optimize.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
Richard Henderson - Sept. 19, 2012, 9:43 p.m.
On 09/19/2012 01:00 PM, Aurelien Jarno wrote:
> It is possible to do copy propagation for all operations, even the ones
> that have side effects or clobber arguments (it only concerns input
> arguments). That said, the call operation should be handled differently
> due to the variable number of arguments.
> 
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

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


r~

Patch

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 244eb02..a58de3b 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -376,8 +376,15 @@  static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         op = gen_opc_buf[op_index];
         def = &tcg_op_defs[op];
         /* Do copy propagation */
-        if (!(def->flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS))) {
-            assert(op != INDEX_op_call);
+        if (op == INDEX_op_call) {
+            int nb_oargs = args[0] >> 16;
+            int nb_iargs = args[0] & 0xffff;
+            for (i = nb_oargs + 1; i < nb_oargs + nb_iargs + 1; i++) {
+                if (temps[args[i]].state == TCG_TEMP_COPY) {
+                    args[i] = find_better_copy(s, args[i]);
+                }
+            }
+        } else {
             for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) {
                 if (temps[args[i]].state == TCG_TEMP_COPY) {
                     args[i] = find_better_copy(s, args[i]);