diff mbox series

[v3,37/48] tcg/optimize: Split out fold_ix_to_i

Message ID 20211021210539.825582-38-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State Superseded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, 0, b => movi r, 0" optimization into a function,
and use it in fold_shift.

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

---
 tcg/optimize.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

-- 
2.25.1

Comments

Luis Fernando Fujita Pires Oct. 25, 2021, 2:26 p.m. UTC | #1 
From: Richard Henderson <richard.henderson@linaro.org>

> Pull the "op r, 0, b => movi r, 0" optimization into a function, and use it in

> fold_shift.

> 

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

> ---

>  tcg/optimize.c | 28 ++++++++++------------------

>  1 file changed, 10 insertions(+), 18 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>
Philippe Mathieu-Daudé Oct. 26, 2021, 7:11 p.m. UTC | #2 
On 10/21/21 23:05, Richard Henderson wrote:
> Pull the "op r, 0, b => movi r, 0" optimization into a function,

> and use it in fold_shift.

> 

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

> ---

>  tcg/optimize.c | 28 ++++++++++------------------

>  1 file changed, 10 insertions(+), 18 deletions(-)


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

Patch

diff --git a/tcg/optimize.c b/tcg/optimize.c
index af26429175..6c1cc3e635 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -731,6 +731,15 @@  static bool fold_to_not(OptContext *ctx, TCGOp *op, int idx)
     return false;
 }
 
+/* If the binary operation has first argument @i, fold to @i. */
+static bool fold_ix_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
+{
+    if (arg_is_const(op->args[1]) && arg_info(op->args[1])->val == i) {
+        return tcg_opt_gen_movi(ctx, op, op->args[0], i);
+    }
+    return false;
+}
+
 /* If the binary operation has first argument @i, fold to NOT. */
 static bool fold_ix_to_not(OptContext *ctx, TCGOp *op, uint64_t i)
 {
@@ -1364,6 +1373,7 @@  static bool fold_sextract(OptContext *ctx, TCGOp *op)
 static bool fold_shift(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
+        fold_ix_to_i(ctx, op, 0) ||
         fold_xi_to_x(ctx, op, 0)) {
         return true;
     }
@@ -1532,24 +1542,6 @@  void tcg_optimize(TCGContext *s)
             break;
         }
 
-        /* Simplify expressions for "shift/rot r, 0, a => movi r, 0",
-           and "sub r, 0, a => neg r, a" case.  */
-        switch (opc) {
-        CASE_OP_32_64(shl):
-        CASE_OP_32_64(shr):
-        CASE_OP_32_64(sar):
-        CASE_OP_32_64(rotl):
-        CASE_OP_32_64(rotr):
-            if (arg_is_const(op->args[1])
-                && arg_info(op->args[1])->val == 0) {
-                tcg_opt_gen_movi(&ctx, op, op->args[0], 0);
-                continue;
-            }
-            break;
-        default:
-            break;
-        }
-
         /* Simplify using known-zero bits. Currently only ops with a single
            output argument is supported. */
         z_mask = -1;