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| author | Ben Gamari <bgamari.foss@gmail.com> | 2018-02-03 11:37:01 -0500 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2018-02-03 11:37:14 -0500 |
| commit | 217e4170bdce3df28a667803ce5e619553bfecdd (patch) | |
| tree | 1e548bae29aecc72ce257dc962025c1388a7a7b5 /mk | |
| parent | fdf518c708dc5a34ae810c5d5f3a4db812d226f0 (diff) | |
| download | haskell-217e4170bdce3df28a667803ce5e619553bfecdd.tar.gz | |
ghc-prim: Emulate C11 atomics when not available
GCC's __sync primitives apparently "usually" imply a full barrier,
meaning they can be used to emulate the more precise C11 atomics albeit
with a loss of efficiency. This restores compatibility with GCC 4.4.
This partially reverts commit 59de290928e6903337f31c1f8107ac8a98ea145d.
Test Plan: Validate on Centos
Reviewers: hvr, simonmar, trommler
Subscribers: rwbarton, thomie, erikd, carter
GHC Trac Issues: #14244
Differential Revision: https://phabricator.haskell.org/D4364
Diffstat (limited to 'mk')
| -rw-r--r-- | mk/config.mk.in | 1 | ||||
| -rw-r--r-- | mk/warnings.mk | 4 |
2 files changed, 4 insertions, 1 deletions
diff --git a/mk/config.mk.in b/mk/config.mk.in index b046abe112..86c626dccd 100644 --- a/mk/config.mk.in +++ b/mk/config.mk.in @@ -522,6 +522,7 @@ GccVersion = @GccVersion@ # TargetPlatformFull retains the string passed to configure so we have it in # the necessary format to pass to libffi's configure. TargetPlatformFull = @TargetPlatformFull@ +GccLT46 = @GccLT46@ GccIsClang = @GccIsClang@ CC = @CC@ diff --git a/mk/warnings.mk b/mk/warnings.mk index 9426db2a1d..0ae81bfcac 100644 --- a/mk/warnings.mk +++ b/mk/warnings.mk @@ -20,11 +20,13 @@ GhcStage2HcOpts += -Wcpp-undef ifneq "$(GccIsClang)" "YES" # Debian doesn't turn -Werror=unused-but-set-variable on by default, so -# we turn it on explicitly for consistency with other users. +# we turn it on explicitly for consistency with other users +ifeq "$(GccLT46)" "NO" # Never set the flag on Windows as the host gcc may be too old. ifneq "$(HostOS_CPP)" "mingw32" SRC_CC_WARNING_OPTS += -Werror=unused-but-set-variable endif +endif # Suppress the warning about __sync_fetch_and_nand (#9678). libraries/ghc-prim/cbits/atomic_CC_OPTS += -Wno-sync-nand |