Displaying 3 results from an estimated 3 matches for "6d9ef706".
2015 Jul 30
2
[LLVMdev] optimizer clobber EFLAGS
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2015 Jul 29
0
[LLVMdev] optimizer clobber EFLAGS
I remember this bug. :) IMO, LLVM should never emit pushf / popf. I'm not
sure this patch to fix it ever got committed:
http://reviews.llvm.org/D6629
On Wed, Jul 29, 2015 at 3:11 PM, Michael Hordijk <hoffbrinkle at hotmail.com>
wrote:
>
> 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
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)