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[10/28] nes: Fix clang 3.6 warning -Wtautological-constant-out-of-range-compare

Message ID 1473109698-31408-11-git-send-email-jgunthorpe@obsidianresearch.com (mailing list archive)
State Superseded
Headers show

Commit Message

Jason Gunthorpe Sept. 5, 2016, 9:08 p.m. UTC 
clang will miscompile this code because it make assumptions
about the signededness of enums.

Instead create a constant for an invalid ibv_wc_opcode and use that
everywhere. Unsigned enums will use -1, signed enums should use INT_MAX.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
---
 libnes/src/nes_uverbs.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/libnes/src/nes_uverbs.c b/libnes/src/nes_uverbs.c
index 12e6222313ad..80891d6243c7 100644
--- a/libnes/src/nes_uverbs.c
+++ b/libnes/src/nes_uverbs.c
@@ -471,13 +471,15 @@  int nes_ima_upoll_cq(struct ibv_cq *cq, int num_entries, struct ibv_wc *entry)
 	}
 
 	while (cqe_count < num_entries) {
-		entry->opcode = -1;
+		const enum ibv_wc_opcode INVAL_OP = -1;
+
+		entry->opcode = INVAL_OP;
 		cqe = &cqes[head];
 		cqe_misc =
 			le32_to_cpu(cqe->cqe_words[NES_NIC_CQE_MISC_IDX]);
 		if (cqe_misc & NES_NIC_CQE_VALID) {
 			memset(entry, 0, sizeof *entry);
-			entry->opcode = -1;
+			entry->opcode = INVAL_OP;
 			cqe->cqe_words[NES_NIC_CQE_MISC_IDX] = 0;
 			entry->status = (cqe_misc & NES_NIC_CQE_ERRV_MASK) >>
 						NES_NIC_CQE_ERRV_SHIFT;
@@ -523,7 +525,7 @@  int nes_ima_upoll_cq(struct ibv_cq *cq, int num_entries, struct ibv_wc *entry)
 			if (++head >= cq_size)
 				head = 0;
 
-			if (entry->opcode != -1) {
+			if (entry->opcode != INVAL_OP) {
 				/* it is possible that no entry will be
 				  available */
 				cqe_count++;