Hi Bruce, Hi Neil, On 11/30/2014 02:05 AM, Neil Horman wrote: > On Fri, Nov 28, 2014 at 03:31:00PM +0000, Bruce Richardson wrote: >> When compiling with clang, errors were being emitted due to truncation >> of values when assigning to the tx_offload_mask bit fields. >> >> dpdk.org/lib/librte_pmd_ixgbe/ixgbe_rxtx.c:404:27: fatal error: implicit >> truncation from 'int' to bitfield changes value from -1 to 127 >> [-Wbitfield-constant-conversion] >> tx_offload_mask.l2_len = ~0; >> >> The fix proposed here is to define a static const value of the same type >> with all fields set to 1s, and use that instead of constants for assigning >> to. >> >> Other options would be to explicitily define the suitable constants that >> would not truncate for each individual field e.g. 0x7f for l2_len, 0x1FF >> for l3_len, etc., but this solution here has the advantage that it works >> without any changes to values if the field sizes are ever modified. >> >> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com> >> --- >> lib/librte_pmd_ixgbe/ixgbe_rxtx.c | 29 +++++++++++++++-------------- >> 1 file changed, 15 insertions(+), 14 deletions(-) >> >> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c >> b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c >> index 8559ef6..4f71194 100644 >> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c >> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c >> @@ -367,6 +367,7 @@ ixgbe_set_xmit_ctx(struct igb_tx_queue* txq, >> volatile struct ixgbe_adv_tx_context_desc *ctx_txd, >> uint64_t ol_flags, union ixgbe_tx_offload tx_offload) >> { >> + static const union ixgbe_tx_offload offload_allones = { .data = ~0 }; > Do you want to make this a static data structure? If you make it a macro like > this: > #define ALLONES {.data = ~0} > Then you save the extra data space in the .data area (not that its that much), > and you can define it in a header file and use it in multiple c files (if you > need to)
I found that the following code works: tx_offload_mask.l2_len |= ~0; (note the '|=' instead of '=') I would avoid to create a macro. What do you think? Regards, Olivier