Mercurial > hg > truffle
comparison src/share/vm/utilities/bitMap.cpp @ 17662:695a6aba51c3
8033545: Missing volatile specifier in Bitmap::par_put_range_within_word
Summary: The method Bitmap::par_put_range_within_word reloads the original value during a CAS, which may be optimized away. Instead of reloading, use the value returned by Atomic::cmpxchg_ptr() for further processing.
Reviewed-by: tschatzl, brutisso, tonyp
Contributed-by: Matthias Braun <matthia.braun@sap.com>
| author | tschatzl |
|---|---|
| date | Mon, 10 Feb 2014 10:34:52 +0100 |
| parents | 55fb97c4c58d |
| children | 8a9bb7821e28 |
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| 17661:a2e452cdf1d5 | 17662:695a6aba51c3 |
|---|---|
| 105 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end); | 105 intptr_t mr = (intptr_t)inverted_bit_mask_for_range(beg, end); |
| 106 intptr_t nw = value ? (w | ~mr) : (w & mr); | 106 intptr_t nw = value ? (w | ~mr) : (w & mr); |
| 107 while (true) { | 107 while (true) { |
| 108 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w); | 108 intptr_t res = Atomic::cmpxchg_ptr(nw, pw, w); |
| 109 if (res == w) break; | 109 if (res == w) break; |
| 110 w = *pw; | 110 w = res; |
| 111 nw = value ? (w | ~mr) : (w & mr); | 111 nw = value ? (w | ~mr) : (w & mr); |
| 112 } | 112 } |
| 113 } | 113 } |
| 114 } | 114 } |
| 115 | 115 |