From c8ccecc783671fb699a33f432c34e3c1cd1dc801 Mon Sep 17 00:00:00 2001 From: Xavier Leroy Date: Thu, 23 Sep 2021 15:33:06 +0200 Subject: For __builtin_memcpy_aligned, watch out for alignment of stack offsets Stack offsets must be multiple of 8 when using ldp/stp instructions and multiple of the transferred size when using other load/store instructions with offsets greater than 256. For simplicity, always require that the offset is multiple of 8. Fixes: #410 --- aarch64/Asmexpand.ml | 1 + 1 file changed, 1 insertion(+) (limited to 'aarch64') diff --git a/aarch64/Asmexpand.ml b/aarch64/Asmexpand.ml index d24a9ef6..6c58e075 100644 --- a/aarch64/Asmexpand.ml +++ b/aarch64/Asmexpand.ml @@ -185,6 +185,7 @@ let memcpy_small_arg sz arg tmp = | BA_addrstack ofs -> if offset_in_range ofs && offset_in_range (Ptrofs.add ofs (Ptrofs.repr (Z.of_uint sz))) + && Int64.rem (Z.to_int64 ofs) 8L = 0L then (XSP, ofs) else begin expand_addimm64 (RR1 tmp) XSP ofs; (RR1 tmp, _0) end | _ -> -- cgit