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| author | Wilco Dijkstra <wdijkstr@arm.com> | 2021-08-10 13:42:07 +0100 |
|---|---|---|
| committer | Wilco Dijkstra <wdijkstr@arm.com> | 2021-08-10 13:42:07 +0100 |
| commit | 186092c6ba8825598ffdbf15dbf0823c771f560d (patch) | |
| tree | 4647b221bbc70a805a9ed30cd7b212e341610c45 | |
| parent | 9bc2ed8f46d80859a5596789cc9e8cc2de84b0e7 (diff) | |
| download | glibc-186092c6ba8825598ffdbf15dbf0823c771f560d.zip glibc-186092c6ba8825598ffdbf15dbf0823c771f560d.tar.gz glibc-186092c6ba8825598ffdbf15dbf0823c771f560d.tar.bz2 | |
[3/5] AArch64: Improve A64FX memset for remaining bytes
Simplify handling of remaining bytes. Avoid lots of taken branches and complex
whilelo computations, instead unconditionally write vectors from the end.
Reviewed-by: Naohiro Tamura <naohirot@fujitsu.com>
| -rw-r--r-- | sysdeps/aarch64/multiarch/memset_a64fx.S | 46 |
1 files changed, 13 insertions, 33 deletions
diff --git a/sysdeps/aarch64/multiarch/memset_a64fx.S b/sysdeps/aarch64/multiarch/memset_a64fx.S index 75cf43a..337c86b 100644 --- a/sysdeps/aarch64/multiarch/memset_a64fx.S +++ b/sysdeps/aarch64/multiarch/memset_a64fx.S @@ -130,38 +130,19 @@ L(unroll8): b 1b L(last): - whilelo p0.b, xzr, rest - whilelo p1.b, vector_length, rest - b.last 1f - st1b z0.b, p0, [dst, #0, mul vl] - st1b z0.b, p1, [dst, #1, mul vl] - ret -1: lsl tmp1, vector_length, 1 // vector_length * 2 - whilelo p2.b, tmp1, rest - incb tmp1 - whilelo p3.b, tmp1, rest - b.last 1f - st1b z0.b, p0, [dst, #0, mul vl] - st1b z0.b, p1, [dst, #1, mul vl] - st1b z0.b, p2, [dst, #2, mul vl] - st1b z0.b, p3, [dst, #3, mul vl] - ret -1: lsl tmp1, vector_length, 2 // vector_length * 4 - whilelo p4.b, tmp1, rest - incb tmp1 - whilelo p5.b, tmp1, rest - incb tmp1 - whilelo p6.b, tmp1, rest - incb tmp1 - whilelo p7.b, tmp1, rest - st1b z0.b, p0, [dst, #0, mul vl] - st1b z0.b, p1, [dst, #1, mul vl] - st1b z0.b, p2, [dst, #2, mul vl] - st1b z0.b, p3, [dst, #3, mul vl] - st1b z0.b, p4, [dst, #4, mul vl] - st1b z0.b, p5, [dst, #5, mul vl] - st1b z0.b, p6, [dst, #6, mul vl] - st1b z0.b, p7, [dst, #7, mul vl] + cmp count, vector_length, lsl 1 + b.ls 2f + add tmp2, vector_length, vector_length, lsl 2 + cmp count, tmp2 + b.ls 5f + st1b z0.b, p0, [dstend, -8, mul vl] + st1b z0.b, p0, [dstend, -7, mul vl] + st1b z0.b, p0, [dstend, -6, mul vl] +5: st1b z0.b, p0, [dstend, -5, mul vl] + st1b z0.b, p0, [dstend, -4, mul vl] + st1b z0.b, p0, [dstend, -3, mul vl] +2: st1b z0.b, p0, [dstend, -2, mul vl] + st1b z0.b, p0, [dstend, -1, mul vl] ret L(L1_prefetch): // if rest >= L1_SIZE @@ -199,7 +180,6 @@ L(L2): subs count, count, CACHE_LINE_SIZE b.hi 1b add count, count, CACHE_LINE_SIZE - add dst, dst, CACHE_LINE_SIZE b L(last) END (MEMSET) |