Displaying 3 results from an estimated 3 matches for "example_not_optim".
2014 Dec 04
2
[LLVMdev] Optimising bit-flipping code
...run that could
detect this optimisation opportunity?
Thanks for any ideas,
/Lars
/***************************************************/
/* The two LSB of x0 are 'tag bits' */
/* that we want to manipulate. */
extern long x0;
void go_error(void) __attribute__ ((noreturn));
void example_not_optimized(void)
{
if((x0 & 3) == 2) {
// Here the tag bits are removed and added
// with bitwise 'and' and 'or'.
x0 = ((x0 & ~3) | 2) + 12;
} else {
go_error();
}
}
/*
define void @example_not_optimized() #0 {
%1 = load i64* @x0, align 8, !tbaa !1
%2 = a...
2015 Jan 15
2
[LLVMdev] generate llvm.assume calls in GVN?
...Thanks for any ideas,
> /Lars
>
> /***************************************************/
>
> /* The two LSB of x0 are 'tag bits' */
> /* that we want to manipulate. */
> extern long x0;
>
> void go_error(void) __attribute__ ((noreturn));
>
> void example_not_optimized(void)
> {
> if((x0 & 3) == 2) {
> // Here the tag bits are removed and added
> // with bitwise 'and' and 'or'.
> x0 = ((x0 & ~3) | 2) + 12;
> } else {
> go_error();
> }
> }
>
> /*
> define void @example_not_optim...
2015 Jan 15
2
[LLVMdev] generate llvm.assume calls in GVN?
...********************************/
>>>
>>> /* The two LSB of x0 are 'tag bits' */
>>> /* that we want to manipulate. */
>>> extern long x0;
>>>
>>> void go_error(void) __attribute__ ((noreturn));
>>>
>>> void example_not_optimized(void)
>>> {
>>> if((x0 & 3) == 2) {
>>> // Here the tag bits are removed and added
>>> // with bitwise 'and' and 'or'.
>>> x0 = ((x0 & ~3) | 2) + 12;
>>> } else {
>>> go_error();
>>&...