Allow wrap-around when subtracting type size to immediate in try_fold_extended_move;

2019-10-08 16:09:26 +02:00
parent 13676cafd1
commit cbbd94db02
2 changed files with 15 additions and 1 deletions
--- a/cranelift/codegen/src/simple_preopt.rs
+++ b/cranelift/codegen/src/simple_preopt.rs
@@ -508,7 +508,7 @@ fn try_fold_extended_move(
            }

            let imm_bits: i64 = imm.into();
-            let ireduce_ty = match dest_ty.lane_bits() as i64 - imm_bits {
+            let ireduce_ty = match (dest_ty.lane_bits() as i64).wrapping_sub(imm_bits) {
                8 => I8,
                16 => I16,
                32 => I32,