Displaying 2 results from an estimated 2 matches for "9c60bdb1".
2015 Jul 29
0
[LLVMdev] optimizer clobber EFLAGS
...> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150729/9c60bdb1/attachment.html>
2015 Jul 29
2
[LLVMdev] optimizer clobber EFLAGS
Using Clang/LLVM 3.6.0 we are observing a case where the optimizations
are clobbering EFLAGS on x86_64. This is inconvenient when the status
of bit 9 (IF), which controls interrupts, changes.
Here's a simple test program. Assume that the external function foo()
modifies the IF bit in EFLAGS.
---
#include <stdlib.h>
#include <stdbool.h>
void foo(void);
int a;
int bar(void)