diff mbox series

[v3,31/48] tcg/optimize: Split out fold_xx_to_x

Message ID 20211021210539.825582-32-richard.henderson@linaro.org
State Superseded
Headers show
Series tcg: optimize redundant sign extensions | expand

Commit Message

Richard Henderson Oct. 21, 2021, 9:05 p.m. UTC 
Pull the "op r, a, a => mov r, a" optimization into a function,
and use it in the outer opcode fold functions.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 tcg/optimize.c | 39 ++++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 15 deletions(-)

-- 
2.25.1

Comments

Luis Fernando Fujita Pires Oct. 22, 2021, 9:04 p.m. UTC | #1 
From: Richard Henderson <richard.henderson@linaro.org>

> Pull the "op r, a, a => mov r, a" optimization into a function, and use it in the

> outer opcode fold functions.

> 

> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  tcg/optimize.c | 39 ++++++++++++++++++++++++---------------

>  1 file changed, 24 insertions(+), 15 deletions(-)


Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>


--
Luis Pires
Instituto de Pesquisas ELDORADO
Aviso Legal - Disclaimer <https://www.eldorado.org.br/disclaimer.html>
diff mbox series

Patch

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 5ac7a45597..8dfe8694da 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -704,8 +704,22 @@  static bool fold_xx_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
     return false;
 }
 
+/* If the binary operation has both arguments equal, fold to identity. */
+static bool fold_xx_to_x(OptContext *ctx, TCGOp *op)
+{
+    if (args_are_copies(op->args[1], op->args[2])) {
+        return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
+    }
+    return false;
+}
+
 /*
  * These outermost fold_<op> functions are sorted alphabetically.
+ *
+ * The ordering of the transformations should be:
+ *   1) those that produce a constant
+ *   2) those that produce a copy
+ *   3) those that produce information about the result value.
  */
 
 static bool fold_add(OptContext *ctx, TCGOp *op)
@@ -748,7 +762,11 @@  static bool fold_add2_i32(OptContext *ctx, TCGOp *op)
 
 static bool fold_and(OptContext *ctx, TCGOp *op)
 {
-    return fold_const2(ctx, op);
+    if (fold_const2(ctx, op) ||
+        fold_xx_to_x(ctx, op)) {
+        return true;
+    }
+    return false;
 }
 
 static bool fold_andc(OptContext *ctx, TCGOp *op)
@@ -1101,7 +1119,11 @@  static bool fold_not(OptContext *ctx, TCGOp *op)
 
 static bool fold_or(OptContext *ctx, TCGOp *op)
 {
-    return fold_const2(ctx, op);
+    if (fold_const2(ctx, op) ||
+        fold_xx_to_x(ctx, op)) {
+        return true;
+    }
+    return false;
 }
 
 static bool fold_orc(OptContext *ctx, TCGOp *op)
@@ -1732,19 +1754,6 @@  void tcg_optimize(TCGContext *s)
             break;
         }
 
-        /* Simplify expression for "op r, a, a => mov r, a" cases */
-        switch (opc) {
-        CASE_OP_32_64_VEC(or):
-        CASE_OP_32_64_VEC(and):
-            if (args_are_copies(op->args[1], op->args[2])) {
-                tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[1]);
-                continue;
-            }
-            break;
-        default:
-            break;
-        }
-
         /*
          * Process each opcode.
          * Sorted alphabetically by opcode as much as possible.