Hi,
This patch is to fix ICE in rewrite_expr_tree_parallel.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110038
Bootstrapped and regtested. Ok for trunk?
Regards
Lili.
1. Limit the value of tree-reassoc-width to IntegerRange(0, 256).
2. Add width limit in rewrite_expr_tree_parallel.
gcc/ChangeLog:
PR tree-optimization/110038
* params.opt: Add a limit on tree-reassoc-width.
* tree-ssa-reassoc.cc
(rewrite_expr_tree_parallel): Add width limit.
gcc/testsuite/ChangeLog:
PR tree-optimization/110038
* gcc.dg/pr110038.c: New test.
---
gcc/params.opt | 2 +-
gcc/testsuite/gcc.dg/pr110038.c | 10 ++++++++++
gcc/tree-ssa-reassoc.cc | 3 +++
3 files changed, 14 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr110038.c
diff --git a/gcc/params.opt b/gcc/params.opt
index 66f1c99036a..70cfb495e3a 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -1091,7 +1091,7 @@ Common Joined UInteger Var(param_tracer_min_branch_ratio)
Init(10) IntegerRange(
Stop reverse growth if the reverse probability of best edge is less than this
threshold (in percent).
-param=tree-reassoc-width=
-Common Joined UInteger Var(param_tree_reassoc_width) Param Optimization
+Common Joined UInteger Var(param_tree_reassoc_width) IntegerRange(0, 256)
Param Optimization
Set the maximum number of instructions executed in parallel in reassociated
tree. If 0, use the target dependent heuristic.
-param=tsan-distinguish-volatile=
diff --git a/gcc/testsuite/gcc.dg/pr110038.c b/gcc/testsuite/gcc.dg/pr110038.c
new file mode 100644
index 00000000000..0f578b182ca
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr110038.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O --param=tree-reassoc-width=256" } */
+
+unsigned a, b;
+
+void
+foo (unsigned c)
+{
+ a += b + c + 1;
+}
diff --git a/gcc/tree-ssa-reassoc.cc b/gcc/tree-ssa-reassoc.cc
index ad2f528ff07..f8055d59d57 100644
--- a/gcc/tree-ssa-reassoc.cc
+++ b/gcc/tree-ssa-reassoc.cc
@@ -5510,6 +5510,9 @@ rewrite_expr_tree_parallel (gassign *stmt, int width,
bool has_fma,
for (i = stmt_num - 2; i >= 0; i--)
stmts[i] = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmts[i+1]));
+ /* Width should not be larger than op_num/2. */
+ width = width <= op_num / 2 ? width : op_num / 2;
+
/* Build parallel dependency chain according to width. */
for (i = 0; i < width; i++)
{
--
2.25.1
