On 18/05/15 11:26, Kyrill Tkachov wrote:
Hi all,
When using the short Thumb2 IT blocks we want to also restrict ifcvt so that it
will not end up generating a number of back-to-back cond_execs
that will later end up being back to back single-instruction IT blocks.
Branching over them should be a better choice.
This patch implements that by setting max_insns_skipped to 1 when
arm_restrict_it.
With this patch, I've seen GCC replace a number of sequences in places like
SPEC2006 from:
it eq
moveq r1, r5
it ne
movne r1, r10
it eq
moveq r8, r4
to a branch over them.
Bootstrapped and tested on arm.
Ok for trunk?
Are you sure TREE_TARGET_THUMB2 is still valid in the code base after
Christian's latest round of ARM / Thumb patches ?
Ramana
Thanks,
Kyrill
2015-05-18 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
* config/arm/arm.c (arm_option_params_internal): When optimising
for speed set max_insns_skipped when arm_restrict_it.
2015-05-18 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
* gcc.target/arm/short-it-ifcvt-1.c: New test.
* gcc.target/arm/short-it-ifcvt-2.c: Likewise.
