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c717b11e0d
MEMORY_BARRIER() as a asm op which clobbers memory to avoid unintended reordering by the compiler.
22 lines
865 B
Plaintext
22 lines
865 B
Plaintext
--- internals.h.orig Tue May 16 00:23:50 2006
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+++ internals.h Tue May 16 00:24:21 2006
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@@ -395,12 +395,14 @@
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#endif
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}
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-/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the architecture
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- doesn't need a memory barrier instruction (e.g. Intel x86). Some
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- architectures distinguish between full, read and write barriers. */
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+/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the
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+ architecture doesn't need a memory barrier instruction (e.g. Intel
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+ x86). Still we need the compiler to respect the barrier and emit
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+ all outstanding operations which modify memory. Some architectures
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+ distinguish between full, read and write barriers. */
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#ifndef MEMORY_BARRIER
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-#define MEMORY_BARRIER()
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+#define MEMORY_BARRIER() asm ("" : : : "memory")
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#endif
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#ifndef READ_MEMORY_BARRIER
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#define READ_MEMORY_BARRIER() MEMORY_BARRIER()
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