[pushed] IRA: Make profitability calculation of RA conflict presentations independent of host compiler type sizes of RA conflict presentations independent of host compiler type sizes [PR102147]
Commit Message
The following patch solves
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102147
The patch was successfully bootstrapped and tested on x86-64.
commit ec4c30b64942e615b4bb4b9761cd3b2635158608 (HEAD -> master)
Author: Vladimir N. Makarov <vmakarov@redhat.com>
Date: Fri Sep 24 10:06:45 2021 -0400
Make profitability calculation of RA conflict presentations
independent of host compiler type sizes. [PR102147]
gcc/ChangeLog:
2021-09-24 Vladimir Makarov <vmakarov@redhat.com>
PR rtl-optimization/102147
* ira-build.c (ira_conflict_vector_profitable_p): Make
profitability calculation independent of host compiler
pointer and
IRA_INT_BITS sizes.
@@ -638,9 +638,14 @@ ira_conflict_vector_profitable_p (ira_object_t obj,
int num)
in allocation. */
return false;
- nw = (max - min + IRA_INT_BITS) / IRA_INT_BITS;
- return (2 * sizeof (ira_object_t) * (num + 1)
- < 3 * nw * sizeof (IRA_INT_TYPE));
+ nbytes = (max - min) / 8 + 1;
+ STATIC_ASSERT (sizeof (ira_object_t) <= 8);
+ /* Don't use sizeof (ira_object_t), use constant 8. Size of
ira_object_t (a
+ pointer) is different on 32-bit and 64-bit targets. Usage sizeof
+ (ira_object_t) can result in different code generation by GCC
built as 32-
+ and 64-bit program. In any case the profitability is just an
estimation
+ and border cases are rare. */
+ return (2 * 8 /* sizeof (ira_object_t) */ * (num + 1) < 3 * nbytes);
}
/* Allocates and initialize the conflict vector of OBJ for NUM
@@ -629,7 +629,7 @@ ior_hard_reg_conflicts (ira_allocno_t a,
const_hard_reg_set set)
bool
ira_conflict_vector_profitable_p (ira_object_t obj, int num)
{
- int nw;
+ int nbytes;
int max = OBJECT_MAX (obj);
int min = OBJECT_MIN (obj);