From: Roland Dreier Date: Wed, 18 Jul 2007 02:30:51 +0000 (-0700) Subject: IB/mthca: Use uninitialized_var() for f0 X-Git-Tag: v2.6.23-rc1~483^2~9 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6d7d080e9f7cd535a8821efd3835c5cfa5223ab6;p=linux-2.6 IB/mthca: Use uninitialized_var() for f0 Commit 9db48926 ("drivers/infiniband/hw/mthca/mthca_qp: kill uninit'd var warning") added "= 0" to the declarations of f0 to shut up gcc warnings. However, there's no point in making the code bigger by initializing f0 to a random value just to get rid of a warning; setting f0 to 0 is no safer than just using uninitialized_var(), which documents the situation better and gives smaller code too. For example, on x86_64: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-16 (-16) function old new delta mthca_tavor_post_send 1352 1344 -8 mthca_arbel_post_send 1489 1481 -8 Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c index 11f1d99db4..0e9ef24f66 100644 --- a/drivers/infiniband/hw/mthca/mthca_qp.c +++ b/drivers/infiniband/hw/mthca/mthca_qp.c @@ -1591,7 +1591,13 @@ int mthca_tavor_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr, int i; int size; int size0 = 0; - u32 f0 = 0; + /* + * f0 is only used if nreq != 0, and f0 will be initialized + * the first time through the main loop, since size0 == 0 the + * first time through. So nreq cannot become non-zero without + * initializing f0, and f0 is in fact never used uninitialized. + */ + u32 uninitialized_var(f0); int ind; u8 op0 = 0; @@ -1946,7 +1952,13 @@ int mthca_arbel_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr, int i; int size; int size0 = 0; - u32 f0 = 0; + /* + * f0 is only used if nreq != 0, and f0 will be initialized + * the first time through the main loop, since size0 == 0 the + * first time through. So nreq cannot become non-zero without + * initializing f0, and f0 is in fact never used uninitialized. + */ + u32 uninitialized_var(f0); int ind; u8 op0 = 0;