In include/asm-mips/interrupt.h, the definition for local_irq_restore is
inconsistent in its use of .reorder/.noreorder assembler directives.
Other asm macros in interrupt.h are wrapped with '.set push' and '.set pop'.
It doesn't seem to be a problem with the 2.96 mipsel-linux- assembler,
but it caused me a problem with my 4.0-based toolchain. (As it was the
local_irq_restore left the assembler in 'reorder' mode and a stack
pointer post-inc was reordered out of the return delay slot where it
belonged.) Luckily we have a sharp compiler guy who figured it out.
Thanks.
As usual, there may be a reason for this, but it took me a whole day to
find it, and I thought I'd point it out.
Ed Martini
$ diff -uN interrupt.h interrupt-new.h
--- interrupt.h 2005-03-29 17:35:02.922362384 -0800
+++ interrupt-new.h 2005-03-29 17:33:26.350770293 -0800
@@ -100,6 +100,7 @@
__asm__ (
".macro\tlocal_irq_restore flags\n\t"
+ ".set\tpush\n\t"
".set\tnoreorder\n\t"
".set\tnoat\n\t"
"mfc0\t$1, $12\n\t"
@@ -109,8 +110,7 @@
"or\t\\flags, $1\n\t"
"mtc0\t\\flags, $12\n\t"
"irq_disable_hazard\n\t"
- ".set\tat\n\t"
- ".set\treorder\n\t"
+ ".set\tpop\n\t"
".endm");
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