The input which overlaps the sign bit of the output can
have its input s_mask propagated to the output s_mask.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
tcg/optimize.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index de32cc0323..e4f68241ce 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1646,8 +1646,9 @@ static bool fold_deposit(OptContext *ctx, TCGOp *op)
TempOptInfo *t2 = arg_info(op->args[2]);
int ofs = op->args[3];
int len = op->args[4];
+ int width;
TCGOpcode and_opc;
- uint64_t z_mask;
+ uint64_t z_mask, s_mask;
if (t1->is_const && t2->is_const) {
return tcg_opt_gen_movi(ctx, op, op->args[0],
@@ -1657,9 +1658,11 @@ static bool fold_deposit(OptContext *ctx, TCGOp *op)
switch (ctx->type) {
case TCG_TYPE_I32:
and_opc = INDEX_op_and_i32;
+ width = 32;
break;
case TCG_TYPE_I64:
and_opc = INDEX_op_and_i64;
+ width = 64;
break;
default:
g_assert_not_reached();
@@ -1684,8 +1687,15 @@ static bool fold_deposit(OptContext *ctx, TCGOp *op)
return fold_and(ctx, op);
}
+ /* The s_mask from the top portion of the deposit is still valid. */
+ if (ofs + len == width) {
+ s_mask = t2->s_mask << ofs;
+ } else {
+ s_mask = t1->s_mask & ~MAKE_64BIT_MASK(0, ofs + len);
+ }
+
z_mask = deposit64(t1->z_mask, ofs, len, t2->z_mask);
- return fold_masks_z(ctx, op, z_mask);
+ return fold_masks_zs(ctx, op, z_mask, s_mask);
}
static bool fold_divide(OptContext *ctx, TCGOp *op)