In this PR the function simplify_control_stmt_condition_1(), which is
responsible for recursing into the operands of a GIMPLE_COND during jump
threading to check for dominating ASSERT_EXPRs, was erroneously
returning a VECTOR_CST when it should instead be returning an
INTEGER_CST. The problem is that the zero/one constants that this
function uses share the type of the GIMPLE_COND's operands, operands
which may be vectors. This makes no sense and there is no reason to
build and use such constants instead of using boolean_[true|false]_node
since all that matters is whether a constant returned by
simplify_control_stmt_condition() correctly satisfies
integer_[zero|one]p. So this patch makes the combining part of
simplify_control_stmt_condition_1() just use boolean_false_node or
boolean_true_node as the designated false/true values.
Does this look OK to commit after bootstrap+regtest on
x86_64-pc-linux-gnu? (I'm not sure if I put the test in the proper
directory since no other test in tree-ssa uses -flto. Also not sure if
an i686 target accepts the -march=core-avx2 flag.)
gcc/ChangeLog:
PR tree-optimization/71077
* tree-ssa-threadedge.c (simplify_control_stmt_condition_1): In
the combining step, use boolean_false_node and boolean_true_node
as the designated false/true return values.
gcc/testsuite/ChangeLog:
PR tree-optimization/71077
* gcc.dg/tree-ssa/pr71077.c: New test.
---
gcc/testsuite/gcc.dg/tree-ssa/pr71077.c | 18 ++++++++++++++++++
gcc/tree-ssa-threadedge.c | 26 ++++++++++++--------------
2 files changed, 30 insertions(+), 14 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr71077.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr71077.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr71077.c
new file mode 100644
index 0000000..4753740
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr71077.c
@@ -0,0 +1,18 @@
+/* PR c++/71077 */
+/* { dg-do link { target { i?86-*-* x86_64-*-* } } } */
+/* { dg-options "-O3 -flto -march=core-avx2" } */
+
+int *a;
+int b, c, d, e;
+int sched_analyze(void) {
+ for (; b; b++) {
+ c = 0;
+ for (; c < 32; c++)
+ if (b & 1 << c)
+ a[b + c] = d;
+ }
+ return 0;
+}
+
+void schedule_insns(void) { e = sched_analyze(); }
+int main(void) { schedule_insns(); }
diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c
index eca3812..826d620 100644
--- a/gcc/tree-ssa-threadedge.c
+++ b/gcc/tree-ssa-threadedge.c
@@ -573,8 +573,6 @@ simplify_control_stmt_condition_1 (edge e,
enum tree_code rhs_code = gimple_assign_rhs_code (def_stmt);
const tree rhs1 = gimple_assign_rhs1 (def_stmt);
const tree rhs2 = gimple_assign_rhs2 (def_stmt);
- const tree zero_cst = build_zero_cst (TREE_TYPE (op0));
- const tree one_cst = build_one_cst (TREE_TYPE (op0));
/* Is A != 0 ? */
const tree res1
@@ -589,19 +587,19 @@ simplify_control_stmt_condition_1 (edge e,
{
/* If A == 0 then (A & B) != 0 is always false. */
if (cond_code == NE_EXPR)
- return zero_cst;
+ return boolean_false_node;
/* If A == 0 then (A & B) == 0 is always true. */
if (cond_code == EQ_EXPR)
- return one_cst;
+ return boolean_true_node;
}
else if (rhs_code == BIT_IOR_EXPR && integer_nonzerop (res1))
{
/* If A != 0 then (A | B) != 0 is always true. */
if (cond_code == NE_EXPR)
- return one_cst;
+ return boolean_true_node;
/* If A != 0 then (A | B) == 0 is always false. */
if (cond_code == EQ_EXPR)
- return zero_cst;
+ return boolean_false_node;
}
/* Is B != 0 ? */
@@ -617,19 +615,19 @@ simplify_control_stmt_condition_1 (edge e,
{
/* If B == 0 then (A & B) != 0 is always false. */
if (cond_code == NE_EXPR)
- return zero_cst;
+ return boolean_false_node;
/* If B == 0 then (A & B) == 0 is always true. */
if (cond_code == EQ_EXPR)
- return one_cst;
+ return boolean_true_node;
}
else if (rhs_code == BIT_IOR_EXPR && integer_nonzerop (res2))
{
/* If B != 0 then (A | B) != 0 is always true. */
if (cond_code == NE_EXPR)
- return one_cst;
+ return boolean_true_node;
/* If B != 0 then (A | B) == 0 is always false. */
if (cond_code == EQ_EXPR)
- return zero_cst;
+ return boolean_false_node;
}
if (res1 != NULL_TREE && res2 != NULL_TREE)
@@ -641,10 +639,10 @@ simplify_control_stmt_condition_1 (edge e,
{
/* If A != 0 and B != 0 then (bool)(A & B) != 0 is true. */
if (cond_code == NE_EXPR)
- return one_cst;
+ return boolean_true_node;
/* If A != 0 and B != 0 then (bool)(A & B) == 0 is false. */
if (cond_code == EQ_EXPR)
- return zero_cst;
+ return boolean_false_node;
}
if (rhs_code == BIT_IOR_EXPR
@@ -653,10 +651,10 @@ simplify_control_stmt_condition_1 (edge e,
{
/* If A == 0 and B == 0 then (A | B) != 0 is false. */
if (cond_code == NE_EXPR)
- return zero_cst;
+ return boolean_false_node;
/* If A == 0 and B == 0 then (A | B) == 0 is true. */
if (cond_code == EQ_EXPR)
- return one_cst;
+ return boolean_true_node;
}
}
}
--
2.9.0.rc0.29.gabd6606
