1. 14 Feb, 2014 5 commits
    • Russ Cox's avatar
      cmd/gc: distinguish unnamed vs blank-named return variables better · a069cf04
      Russ Cox authored
      Before, an unnamed return value turned into an ONAME node n with n->sym
      named ~anon%d, and n->orig == n.
      
      A blank-named return value turned into an ONAME node n with n->sym
      named ~anon%d but n->orig == the original blank n. Code generation and
      printing uses n->orig, so that this node formatted as _.
      
      But some code does not use n->orig. In particular the liveness code does
      not know about the n->orig convention and so mishandles blank identifiers.
      It is possible to fix but seemed better to avoid the confusion entirely.
      
      Now the first kind of node is named ~r%d and the second ~b%d; both have
      n->orig == n, so that it doesn't matter whether code uses n or n->orig.
      
      After this change the ->orig field is only used for other kinds of expressions,
      not for ONAME nodes.
      
      This requires distinguishing ~b from ~r names in a few places that care.
      It fixes a liveness analysis bug without actually changing the liveness code.
      
      TBR=ken2
      CC=golang-codereviews
      https://golang.org/cl/63630043
      a069cf04
    • Russ Cox's avatar
      cmd/gc: relax address-of escape analysis · e5d742fc
      Russ Cox authored
      Make the loop nesting depth of &x depend on where x is declared,
      not on where the &x appears. The latter is only a conservative
      estimate of the former. Being more careful can avoid some
      variables escaping, and it is easier to reason about.
      
      It would have avoided issue 7313, although that was still a bug
      worth fixing.
      
      Not much effect in the tree: one variable in the whole tree
      is saved from a heap allocation (something in x509 parsing).
      
      LGTM=daniel.morsing
      R=daniel.morsing
      CC=golang-codereviews
      https://golang.org/cl/62380043
      e5d742fc
    • Markus Zimmermann's avatar
      container/list: mark must be an element of the list · e0bb5ba5
      Markus Zimmermann authored
      The methods MoveAfter and MoveBefore of the container/list package did silently corrupt the interal structure of the list if a mark element is used which is not an element of the list.
      
      LGTM=gri
      R=golang-codereviews, gobot, gri
      CC=golang-codereviews
      https://golang.org/cl/60980043
      e0bb5ba5
    • Robert Griesemer's avatar
      A+C: Markus Zimmermann (individual CLA) · a9495638
      Robert Griesemer authored
      Generated by addca.
      
      R=gobot
      CC=golang-codereviews
      https://golang.org/cl/63620043
      a9495638
    • Nick Craig-Wood's avatar
      math/big: Optimise ARM assembler · eae09a59
      Nick Craig-Wood authored
      Tweak the ARM assembler to improve its performance.
      
        * Use TEQ instead of CMP which preserves the carry flag.  This means
          we can avoid saving and restoring CPSR which is very slow.
      
        * Use conditional instructions to read the value of the carry flag.
      
        * Use 3 argument ARM instructions to save instructions
      
        * Improve scheduling for MOVW instructions (LDR)
      
        * Use RSB constant to save an instruction in bitLen
      
      Results of -test.bench 'VV|VW|VU|WW|Bit' -test.benchtime 3s on Samsung
      Exynos5 Chromebook.
      
      There are a few small regressions in the benchmarks which I believe to
      be noise, perhaps due to different cacheline alignment.
      
      The changes to bitLen are apparently no faster, however less
      instructions means less I-cache usage which is a win. I suspect it
      will be a win on older ARM processors.
      
      benchmark                 old ns/op    new ns/op    delta
      BenchmarkAddVV_1                 48           14  -70.84%
      BenchmarkAddVV_2                 87           17  -80.25%
      BenchmarkAddVV_3                126           20  -83.97%
      BenchmarkAddVV_4                165           23  -86.00%
      BenchmarkAddVV_5                204           26  -87.21%
      BenchmarkAddVV_1e1              399           41  -89.72%
      BenchmarkAddVV_1e2             3921          315  -91.97%
      BenchmarkAddVV_1e3            39085         2972  -92.40%
      BenchmarkAddVV_1e4           390330        29623  -92.41%
      BenchmarkAddVV_1e5          3935366       343431  -91.27%
      BenchmarkAddVW_1                 20           10  -49.04%
      BenchmarkAddVW_2                 60           14  -76.53%
      BenchmarkAddVW_3                 99           16  -83.38%
      BenchmarkAddVW_4                140           18  -86.50%
      BenchmarkAddVW_5                179           21  -88.04%
      BenchmarkAddVW_1e1              376           33  -91.20%
      BenchmarkAddVW_1e2             3933          256  -93.49%
      BenchmarkAddVW_1e3            39630         2378  -94.00%
      BenchmarkAddVW_1e4           396218        23623  -94.04%
      BenchmarkAddVW_1e5          3972901       238403  -94.00%
      BenchmarkAddMulVVW_1             11           11   -4.27%
      BenchmarkAddMulVVW_2             15           15   +0.00%
      BenchmarkAddMulVVW_3             18           19   +4.37%
      BenchmarkAddMulVVW_4             21           21   +4.29%
      BenchmarkAddMulVVW_5             24           24   -0.82%
      BenchmarkAddMulVVW_1e1           40           39   -2.70%
      BenchmarkAddMulVVW_1e2          329          326   -0.91%
      BenchmarkAddMulVVW_1e3         3200         3098   -3.19%
      BenchmarkAddMulVVW_1e4        38457        40013   +4.05%
      BenchmarkAddMulVVW_1e5       461880       428580   -7.21%
      BenchmarkBitLen0                  5            5   -0.19%
      BenchmarkBitLen1                  5            5   +0.00%
      BenchmarkBitLen2                  5            5   -0.56%
      BenchmarkBitLen3                  5            5   +0.38%
      BenchmarkBitLen4                  5            5   +0.19%
      BenchmarkBitLen5                  5            5   +0.56%
      BenchmarkBitLen8                  5            5   -0.19%
      BenchmarkBitLen9                  5            5   -0.56%
      BenchmarkBitLen16                 5            5   -0.19%
      BenchmarkBitLen17                 5            5   -0.37%
      BenchmarkBitLen31                 5            5   -1.30%
      BenchmarkBitset                  72           70   -2.49%
      BenchmarkBitsetNeg             1584          396  -75.00%
      BenchmarkBitsetOrig            1990         1980   -0.50%
      BenchmarkBitsetNegOrig         4031         2877  -28.63%
      
      benchmark                  old MB/s     new MB/s  speedup
      BenchmarkAddVV_1             657.71      2251.28    3.42x
      BenchmarkAddVV_2             730.65      3700.37    5.06x
      BenchmarkAddVV_3             757.29      4754.30    6.28x
      BenchmarkAddVV_4             772.95      5541.58    7.17x
      BenchmarkAddVV_5             781.30      6125.59    7.84x
      BenchmarkAddVV_1e1           800.33      7814.14    9.76x
      BenchmarkAddVV_1e2           815.98     10129.62   12.41x
      BenchmarkAddVV_1e3           818.73     10767.07   13.15x
      BenchmarkAddVV_1e4           819.82     10802.12   13.18x
      BenchmarkAddVV_1e5           813.14      9317.73   11.46x
      BenchmarkAddVW_1            1539.56      3006.13    1.95x
      BenchmarkAddVW_2            1057.66      4502.20    4.26x
      BenchmarkAddVW_3             960.67      5797.65    6.04x
      BenchmarkAddVW_4             913.19      6776.86    7.42x
      BenchmarkAddVW_5             891.72      7467.82    8.37x
      BenchmarkAddVW_1e1           850.12      9681.85   11.39x
      BenchmarkAddVW_1e2           813.48     12494.27   15.36x
      BenchmarkAddVW_1e3           807.45     13451.80   16.66x
      BenchmarkAddVW_1e4           807.64     13545.64   16.77x
      BenchmarkAddVW_1e5           805.46     13422.64   16.66x
      BenchmarkAddMulVVW_1        2727.29      2847.66    1.04x
      BenchmarkAddMulVVW_2        4162.30      4158.69    1.00x
      BenchmarkAddMulVVW_3        5236.91      5015.98    0.96x
      BenchmarkAddMulVVW_4        6090.27      5837.52    0.96x
      BenchmarkAddMulVVW_5        6549.86      6598.60    1.01x
      BenchmarkAddMulVVW_1e1      7850.72      8068.00    1.03x
      BenchmarkAddMulVVW_1e2      9724.38      9794.40    1.01x
      BenchmarkAddMulVVW_1e3      9997.18     10328.58    1.03x
      BenchmarkAddMulVVW_1e4      8320.88      7997.39    0.96x
      BenchmarkAddMulVVW_1e5      6928.20      7466.50    1.08x
      
      LGTM=gri
      R=golang-codereviews, dave, gri
      CC=golang-codereviews
      https://golang.org/cl/61290043
      eae09a59
  2. 13 Feb, 2014 28 commits
  3. 12 Feb, 2014 7 commits