From: Jiufu Guo <guoji...@linux.ibm.com>
Currently GIMPLE complete unroller(cunroll) is checking
flag_unroll_loops and flag_peel_loops to see if allow size growth.
Beside affects curnoll, flag_unroll_loops also controls RTL unroler.
To have more freedom to control cunroll and RTL unroller, this patch
introduces flag_cunroll_grow_size. With this patch, we can control
cunroll and RTL unroller indepently.
Bootstrap/regtest pass on powerpc64le. OK for trunk? And backport to
GCC10 after week?
gcc/ChangeLog
2020-02-28 Jiufu Guo <guoji...@linux.ibm.com>
* common.opt (flag_cunroll_grow_size): New flag.
* toplev.c (process_options): Set flag_cunroll_grow_size.
* tree-ssa-loop-ivcanon.c (pass_complete_unroll::execute):
Use flag_cunroll_grow_size.
---
gcc/common.opt | 4 ++++
gcc/toplev.c | 4 ++++
gcc/tree-ssa-loop-ivcanon.c | 3 +--
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/gcc/common.opt b/gcc/common.opt
index 4464049fc1f..1d0fa7b1749 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2856,6 +2856,10 @@ funroll-all-loops
Common Report Var(flag_unroll_all_loops) Optimization
Perform loop unrolling for all loops.
+funroll-completely-grow-size
+Var(flag_cunroll_grow_size) Init(2)
+; Control cunroll to allow size growth during complete unrolling
+
; Nonzero means that loop optimizer may assume that the induction variables
; that control loops do not overflow and that the loops with nontrivial
; exit condition are not infinite
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 96316fbd23b..8d52358efdd 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1474,6 +1474,10 @@ process_options (void)
if (flag_unroll_all_loops)
flag_unroll_loops = 1;
+ /* Allow cunroll to grow size accordingly. */
+ if (flag_cunroll_grow_size == AUTODETECT_VALUE)
+ flag_cunroll_grow_size = flag_unroll_loops || flag_peel_loops;
+
/* web and rename-registers help when run after loop unrolling. */
if (flag_web == AUTODETECT_VALUE)
flag_web = flag_unroll_loops;
diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
index 8ab6ab3330c..d6a4617a6a1 100644
--- a/gcc/tree-ssa-loop-ivcanon.c
+++ b/gcc/tree-ssa-loop-ivcanon.c
@@ -1603,8 +1603,7 @@ pass_complete_unroll::execute (function *fun)
re-peeling the same loop multiple times. */
if (flag_peel_loops)
peeled_loops = BITMAP_ALLOC (NULL);
- unsigned int val = tree_unroll_loops_completely (flag_unroll_loops
- || flag_peel_loops
+ unsigned int val = tree_unroll_loops_completely (flag_cunroll_grow_size
|| optimize >= 3, true);
if (peeled_loops)
{
--
2.17.1
