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| author | Andrew Waterman <andrew@sifive.com> | 2019-09-28 16:52:31 +0200 |
|---|---|---|
| committer | Andrew Waterman <andrew@sifive.com> | 2020-10-17 14:43:15 -0700 |
| commit | eeaed2ccd292ea8668b5c1db4d5ce54e7432cfba (patch) | |
| tree | 693cf962d7e067a84fa54cf1dbcf2fb69b626db1 | |
| parent | ea9410a6a5ea2b7cabfbef1ed0bf3507bb784c36 (diff) | |
| download | riscv-isa-manual-eeaed2ccd292ea8668b5c1db4d5ce54e7432cfba.zip riscv-isa-manual-eeaed2ccd292ea8668b5c1db4d5ce54e7432cfba.tar.gz riscv-isa-manual-eeaed2ccd292ea8668b5c1db4d5ce54e7432cfba.tar.bz2 | |
Add note about PAUSE and LR/SC forward progress
| -rw-r--r-- | src/zihintpause.tex | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/zihintpause.tex b/src/zihintpause.tex index 82b62a7..047a04e 100644 --- a/src/zihintpause.tex +++ b/src/zihintpause.tex @@ -29,6 +29,9 @@ memory transactions have completed. Because the successor set is null, however, PAUSE does not {\em mandate} any particular memory ordering---hence, it truly is a HINT. +Like other FENCE instructions, PAUSE cannot be used within LR/SC sequences +without voiding the forward-progress guarantee. + The choice of a predecessor set of W is arbitrary, since the successor set is null. Other HINTs similar to PAUSE might be encoded with other predecessor sets. |