Re: [PATCH v3 64/66] tcg: Canonicalize alignment flags in MemOp

[Philippe Mathieu-Daudé]

On 8/18/21 9:19 PM, Richard Henderson wrote:
> Having observed e.g. al8+leq in dumps, canonicalize to al+leq.
> 
> Signed-off-by: Richard Henderson 
> ---
>  tcg/tcg-op.c | 7 ++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

Nice.

Reviewed-by: Philippe Mathieu-Daudé 

[PATCH v3 64/66] tcg: Canonicalize alignment flags in MemOp

[Richard Henderson]

Having observed e.g. al8+leq in dumps, canonicalize to al+leq.

Signed-off-by: Richard Henderson 
---
 tcg/tcg-op.c | 7 ++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index b1cfd36f29..61b492d89f 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2765,7 +2765,12 @@ void tcg_gen_lookup_and_goto_ptr(void)
 static inline MemOp tcg_canonicalize_memop(MemOp op, bool is64, bool st)
 {
 /* Trigger the asserts within as early as possible.  */
-(void)get_alignment_bits(op);
+unsigned a_bits = get_alignment_bits(op);
+
+/* Prefer MO_ALIGN+MO_XX over MO_ALIGN_XX+MO_XX */
+if (a_bits == (op & MO_SIZE)) {
+op = (op & ~MO_AMASK) | MO_ALIGN;
+}
 
 switch (op & MO_SIZE) {
 case MO_8:
-- 
2.25.1