https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85368
Christophe Lyon <clyon at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |clyon at gcc dot gnu.org
--- Comment #8 from Christophe Lyon <clyon at gcc dot gnu.org> ---
I see a regression:
FAIL: gcc.dg/tree-ssa/phi-opt-11.c scan-tree-dump-times optimized "if" 0
(used to have PASS: gcc.dg/tree-ssa/phi-opt-11.c scan-tree-dump-times optimized
"if" 2)
on arm-none-eabi --with-mode thumb --with-cpu cortex-m3
Jakub said:
> I've tested it on x86_64 as example of
> !logical_op_short_circuit && branch_cost
> target, Jeff/Andreas on s390x as example
> of logical_op_short_circuit &&
> branch_cost target and I've tested on
> powerpc64{,le} as example of
> logical_op_short_circuit && !branch_cost target.
> arm is a branch_cost target and cortex-m3 is
> logical_op_short_circuit, why
> doesn't the -mbranch-cost=2 option override
> the cortex-m3 defaults?
That's not clear. We have:
#define BRANCH_COST(speed_p, predictable_p) \
((arm_branch_cost != -1) ? arm_branch_cost : \
(current_tune->branch_cost (speed_p, predictable_p)))
static int
arm_cortex_m_branch_cost (bool speed_p, bool predictable_p)
{
return (TARGET_32BIT && speed_p) ? 1
: arm_default_branch_cost (speed_p, predictable_p);
}
But since arm_branch_cost=2, we should just use that.
