target/arm: Fix MVE VSLI by 0 and VSRI by <dt>
In the MVE shift-and-insert insns, we special case VSLI by 0
and VSRI by <dt>. VSRI by <dt> means "don't update the destination",
which is what we've implemented. However VSLI by 0 is "set
destination to the input", so we don't want to use the same
special-casing that we do for VSRI by <dt>.
Since the generic logic gives the right answer for a shift
by 0, just use that.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/target/arm/mve_helper.c b/target/arm/mve_helper.c
index db5d622..f14fa91 100644
--- a/target/arm/mve_helper.c
+++ b/target/arm/mve_helper.c
@@ -1279,11 +1279,12 @@
uint16_t mask; \
uint64_t shiftmask; \
unsigned e; \
- if (shift == 0 || shift == ESIZE * 8) { \
+ if (shift == ESIZE * 8) { \
/* \
- * Only VSLI can shift by 0; only VSRI can shift by <dt>. \
- * The generic logic would give the right answer for 0 but \
- * fails for <dt>. \
+ * Only VSRI can shift by <dt>; it should mean "don't \
+ * update the destination". The generic logic can't handle \
+ * this because it would try to shift by an out-of-range \
+ * amount, so special case it here. \
*/ \
goto done; \
} \
