Tim Armstrong has uploaded a new change for review.
http://gerrit.cloudera.org:8080/2735
Change subject: Use more efficient gutil implementation of Log2Ceiling
......................................................................
Use more efficient gutil implementation of Log2Ceiling
This was used in FreePool::Allocate, which is called a lot in some
workloads, so may have some perf impact. I was looking at using this
function for an allocator for the new buffer pool and it makes the
allocator code simpler if I can call this function freely without
perf concerns.
Modified gutil's implementation slightly so that gcc optimises it to
the following branch-free code:
.LHOTB8:
.align 2
.p2align 4,,15
.globl _ZN4Bits20Log2CeilingNonZero64Ey
.type _ZN4Bits20Log2CeilingNonZero64Ey, @function
_ZN4Bits20Log2CeilingNonZero64Ey:
.LFB1797:
.loc 1 90 0
.cfi_startproc
.LVL40:
.LBB33:
.loc 1 92 0
leaq -1(%rdi), %rdx #, D.40305
.LBB34:
.LBB35:
.loc 2 155 0
bsrq %rdi, %rax # n, tmp89
.LVL41:
.LBE35:
.LBE34:
.loc 1 92 0
andq %rdx, %rdi # D.40305, D.40305
.LVL42:
.loc 1 95 0
cmpq $1, %rdi #, D.40305
sbbl $-1, %eax #, D.40304
.LVL43:
.LBE33:
.loc 1 96 0
ret
.cfi_endproc
Change-Id: Ifbffb49b5c86394e5a9ccd711132543856321be0
---
M be/src/exec/hdfs-parquet-scanner.cc
M be/src/gutil/bits.cc
M be/src/gutil/bits.h
M be/src/runtime/disk-io-mgr.cc
M be/src/runtime/free-pool.h
M be/src/runtime/runtime-filter.cc
M be/src/util/bit-util-test.cc
M be/src/util/bit-util.h
M be/src/util/bloom-filter.h
M be/src/util/dict-encoding.h
10 files changed, 65 insertions(+), 55 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala refs/changes/35/2735/1
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Gerrit-MessageType: newchange
Gerrit-Change-Id: Ifbffb49b5c86394e5a9ccd711132543856321be0
Gerrit-PatchSet: 1
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Tim Armstrong <[email protected]>
