diff mbox series

[v3,36/48] tcg/optimize: Split out fold_xi_to_x

Message ID 20211021210539.825582-37-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State Superseded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, i => mov r, a" optimization into a function,
and use them int the outer-most logical operations.

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

---
 tcg/optimize.c | 60 +++++++++++++++++++++-----------------------------
 1 file changed, 25 insertions(+), 35 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, a, i => mov r, a" optimization into a function, and use them int the

> outer-most logical operations.


Typo: "int" -> "in".

> -        /* Simplify expression for "op r, a, const => mov r, a" cases */

> -        switch (opc) {

> -        CASE_OP_32_64_VEC(add):

> -        CASE_OP_32_64_VEC(sub):

> -        CASE_OP_32_64_VEC(or):

> -        CASE_OP_32_64_VEC(xor):

> -        CASE_OP_32_64_VEC(andc):

> -        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_is_const(op->args[2])

> -                && arg_info(op->args[2])->val == 0) {

> -                tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[1]);

> -                continue;

> -            }

> -            break;

> -        CASE_OP_32_64_VEC(and):

> -        CASE_OP_32_64_VEC(orc):


You missed adding 'fold_xi_to_x(ctx, op, -1)' to fold_orc() in this commit.
It ended up being added in patch 42, but it should be here.

And should we use fold_xi_to_x() to optimize multiply and divide when i==1, too?

--
Luis Pires
Instituto de Pesquisas ELDORADO
Aviso Legal - Disclaimer <https://www.eldorado.org.br/disclaimer.html>
Richard Henderson Oct. 25, 2021, 5:46 p.m. UTC | #2 
On 10/25/21 7:26 AM, Luis Fernando Fujita Pires wrote:
> You missed adding 'fold_xi_to_x(ctx, op, -1)' to fold_orc() in this commit.

> It ended up being added in patch 42, but it should be here.


Oops, yes.

> And should we use fold_xi_to_x() to optimize multiply and divide when i==1, too?


A good idea; I'll put that in a new patch.


r~
diff mbox series

Patch

diff --git a/tcg/optimize.c b/tcg/optimize.c
index e4cf746321..af26429175 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -749,6 +749,15 @@  static bool fold_xi_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
     return false;
 }
 
+/* If the binary operation has second argument @i, fold to identity. */
+static bool fold_xi_to_x(OptContext *ctx, TCGOp *op, uint64_t i)
+{
+    if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == i) {
+        return tcg_opt_gen_mov(ctx, op, op->args[0], op->args[1]);
+    }
+    return false;
+}
+
 /* If the binary operation has second argument @i, fold to NOT. */
 static bool fold_xi_to_not(OptContext *ctx, TCGOp *op, uint64_t i)
 {
@@ -787,7 +796,11 @@  static bool fold_xx_to_x(OptContext *ctx, TCGOp *op)
 
 static bool fold_add(OptContext *ctx, TCGOp *op)
 {
-    return fold_const2(ctx, op);
+    if (fold_const2(ctx, op) ||
+        fold_xi_to_x(ctx, op, 0)) {
+        return true;
+    }
+    return false;
 }
 
 static bool fold_addsub2_i32(OptContext *ctx, TCGOp *op, bool add)
@@ -827,6 +840,7 @@  static bool fold_and(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
         fold_xi_to_i(ctx, op, 0) ||
+        fold_xi_to_x(ctx, op, -1) ||
         fold_xx_to_x(ctx, op)) {
         return true;
     }
@@ -837,6 +851,7 @@  static bool fold_andc(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
         fold_xx_to_i(ctx, op, 0) ||
+        fold_xi_to_x(ctx, op, 0) ||
         fold_ix_to_not(ctx, op, -1)) {
         return true;
     }
@@ -1039,6 +1054,7 @@  static bool fold_dup2(OptContext *ctx, TCGOp *op)
 static bool fold_eqv(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
+        fold_xi_to_x(ctx, op, -1) ||
         fold_xi_to_not(ctx, op, 0)) {
         return true;
     }
@@ -1223,6 +1239,7 @@  static bool fold_not(OptContext *ctx, TCGOp *op)
 static bool fold_or(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
+        fold_xi_to_x(ctx, op, 0) ||
         fold_xx_to_x(ctx, op)) {
         return true;
     }
@@ -1346,7 +1363,11 @@  static bool fold_sextract(OptContext *ctx, TCGOp *op)
 
 static bool fold_shift(OptContext *ctx, TCGOp *op)
 {
-    return fold_const2(ctx, op);
+    if (fold_const2(ctx, op) ||
+        fold_xi_to_x(ctx, op, 0)) {
+        return true;
+    }
+    return false;
 }
 
 static bool fold_sub_to_neg(OptContext *ctx, TCGOp *op)
@@ -1389,6 +1410,7 @@  static bool fold_sub(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
         fold_xx_to_i(ctx, op, 0) ||
+        fold_xi_to_x(ctx, op, 0) ||
         fold_sub_to_neg(ctx, op)) {
         return true;
     }
@@ -1404,6 +1426,7 @@  static bool fold_xor(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
         fold_xx_to_i(ctx, op, 0) ||
+        fold_xi_to_x(ctx, op, 0) ||
         fold_xi_to_not(ctx, op, -1)) {
         return true;
     }
@@ -1527,39 +1550,6 @@  void tcg_optimize(TCGContext *s)
             break;
         }
 
-        /* Simplify expression for "op r, a, const => mov r, a" cases */
-        switch (opc) {
-        CASE_OP_32_64_VEC(add):
-        CASE_OP_32_64_VEC(sub):
-        CASE_OP_32_64_VEC(or):
-        CASE_OP_32_64_VEC(xor):
-        CASE_OP_32_64_VEC(andc):
-        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_is_const(op->args[2])
-                && arg_info(op->args[2])->val == 0) {
-                tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[1]);
-                continue;
-            }
-            break;
-        CASE_OP_32_64_VEC(and):
-        CASE_OP_32_64_VEC(orc):
-        CASE_OP_32_64(eqv):
-            if (!arg_is_const(op->args[1])
-                && arg_is_const(op->args[2])
-                && arg_info(op->args[2])->val == -1) {
-                tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[1]);
-                continue;
-            }
-            break;
-        default:
-            break;
-        }
-
         /* Simplify using known-zero bits. Currently only ops with a single
            output argument is supported. */
         z_mask = -1;