diff mbox

[dpdk-dev,v2,5/5] lib/librte_eal: Tune memcpy for prior platforms

Message ID 1453086314-30158-6-git-send-email-zhihong.wang@intel.com (mailing list archive)
State Accepted, archived
Delegated to: Thomas Monjalon
Headers

Commit Message

Zhihong Wang Jan. 18, 2016, 3:05 a.m. UTC 
  For prior platforms, add condition for unalignment handling, to keep this
operation from interrupting the batch copy loop for aligned cases.

Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
---
 .../common/include/arch/x86/rte_memcpy.h           | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)
diff mbox

Patch

diff --git a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
index fee954a..d965957 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
@@ -513,10 +513,12 @@  COPY_BLOCK_64_BACK31:
 	 * Make store aligned when copy size exceeds 512 bytes
 	 */
 	dstofss = 32 - ((uintptr_t)dst & 0x1F);
-	n -= dstofss;
-	rte_mov32((uint8_t *)dst, (const uint8_t *)src);
-	src = (const uint8_t *)src + dstofss;
-	dst = (uint8_t *)dst + dstofss;
+	if (dstofss > 0) {
+		n -= dstofss;
+		rte_mov32((uint8_t *)dst, (const uint8_t *)src);
+		src = (const uint8_t *)src + dstofss;
+		dst = (uint8_t *)dst + dstofss;
+	}
 
 	/**
 	 * Copy 256-byte blocks.
@@ -833,11 +835,13 @@  COPY_BLOCK_64_BACK15:
 	 * backwards access.
 	 */
 	dstofss = 16 - ((uintptr_t)dst & 0x0F) + 16;
-	n -= dstofss;
-	rte_mov32((uint8_t *)dst, (const uint8_t *)src);
-	src = (const uint8_t *)src + dstofss;
-	dst = (uint8_t *)dst + dstofss;
-	srcofs = ((uintptr_t)src & 0x0F);
+	if (dstofss > 0) {
+		n -= dstofss;
+		rte_mov32((uint8_t *)dst, (const uint8_t *)src);
+		src = (const uint8_t *)src + dstofss;
+		dst = (uint8_t *)dst + dstofss;
+		srcofs = ((uintptr_t)src & 0x0F);
+	}
 
 	/**
 	 * For aligned copy