mirror of
git://projects.qi-hardware.com/wernermisc.git
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49 lines
1.7 KiB
Diff
49 lines
1.7 KiB
Diff
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This patch is under review:
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https://www.rtems.org/bugzilla/show_bug.cgi?id=1956
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The comments in cpukit/score/cpu/lm32/rtems/score/cpu.h state that
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CPU_STACK_ALIGNMENT should either be 0 or >= CPU_ALIGNMENT. The
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latter was 8, the former is 4.
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Further investigation revealed that, contrary to what the comment
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says, 0 is not a valid value for CPU_STACK_ALIGNMENT.
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This patch sets CPU_ALIGNMENT to 4, since we don't have any machine
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word larger than that. (doubles and long longs are handled by
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software and either extremely slow already or rare.)
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The patch also corrects the misleading comment before
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CPU_STACK_ALIGNMENT.
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I'm not sure if this fix has any real-life impact on M1 behaviour,
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but I guess it can't hurt.
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- Werner
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Index: rtems/cpukit/score/cpu/lm32/rtems/score/cpu.h
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===================================================================
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--- rtems.orig/cpukit/score/cpu/lm32/rtems/score/cpu.h 2011-11-12 03:01:35.000000000 -0300
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+++ rtems/cpukit/score/cpu/lm32/rtems/score/cpu.h 2011-11-12 03:03:46.000000000 -0300
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@@ -637,7 +637,7 @@
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*
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* XXX document implementation including references if appropriate
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*/
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-#define CPU_ALIGNMENT 8
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+#define CPU_ALIGNMENT 4
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/**
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* This number corresponds to the byte alignment requirement for the
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@@ -687,9 +687,10 @@
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* stack. This alignment requirement may be stricter than that for the
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* data types alignment specified by @ref CPU_ALIGNMENT. If the
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* @ref CPU_ALIGNMENT is strict enough for the stack, then this should be
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- * set to 0.
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+ * set to @ref CPU_ALIGNMENT.
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*
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- * @note This must be a power of 2 either 0 or greater than @ref CPU_ALIGNMENT.
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+ * @note This must be a power of 2 either equal to or greater than
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+ * @ref CPU_ALIGNMENT.
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*
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* Port Specific Information:
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*
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