Signed-off-by: Richard Henderson <r...@twiddle.net>
---
tcg/optimize.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index d3b099a..3291a08 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -727,6 +727,17 @@ static TCGArg *tcg_constant_folding(TCGContext *s,
uint16_t *tcg_opc_ptr,
mask = temps[args[1]].mask & mask;
break;
+ CASE_OP_32_64(andc):
+ /* Known-zeros does not imply known-ones. Therefore unless
+ args[2] is constant, we can't infer anything from it. */
+ if (temps[args[2]].state == TCG_TEMP_CONST) {
+ mask = ~temps[args[2]].mask;
+ goto and_const;
+ }
+ /* But we certainly know nothing outside args[1] may be set. */
+ mask = temps[args[1]].mask;
+ break;
+
case INDEX_op_sar_i32:
if (temps[args[2]].state == TCG_TEMP_CONST) {
mask = (int32_t)temps[args[1]].mask >> temps[args[2]].val;
--
1.8.5.3
