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.hender...@linaro.org>
---
tcg/optimize.c | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
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;
--
2.25.1
