[Qemu-devel] [PATCH 1/2] tcg: Restrict check_size_impl to multiples of the line size

[Richard Henderson]

Normally this is automatic in the size restrictions that are placed
on vector sizes coming from the implementation.  However, for the
legitimate size tuple [oprsz=8, maxsz=32], we need to clear the final
24 bytes of the vector register.  Without this check, do_dup selects
TCG_TYPE_V128 and clears only 16 bytes.

Signed-off-by: Richard Henderson <address@hidden>
---
 tcg/tcg-op-gvec.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tcg/tcg-op-gvec.c b/tcg/tcg-op-gvec.c
index 22db1590d5..61c25f5784 100644
--- a/tcg/tcg-op-gvec.c
+++ b/tcg/tcg-op-gvec.c
@@ -287,8 +287,11 @@ void tcg_gen_gvec_4_ptr(uint32_t dofs, uint32_t aofs, 
uint32_t bofs,
    in units of LNSZ.  This limits the expansion of inline code.  */
 static inline bool check_size_impl(uint32_t oprsz, uint32_t lnsz)
 {
-    uint32_t lnct = oprsz / lnsz;
-    return lnct >= 1 && lnct <= MAX_UNROLL;
+    if (oprsz % lnsz == 0) {
+        uint32_t lnct = oprsz / lnsz;
+        return lnct >= 1 && lnct <= MAX_UNROLL;
+    }
+    return false;
 }
 
 static void expand_clr(uint32_t dofs, uint32_t maxsz);
-- 
2.17.1