The canonicalization of args code was originally thinking edges e1/e2
were edges out going from the cond block but they were the edges
coming into the join block. This rewrites the canonicalization of arg0/1
args to correct that mistake. And it fixes the wrong code that would
happen in this case.
PR tree-optimization/123645
gcc/ChangeLog:
* tree-ssa-phiopt.cc (cond_removal_in_builtin_zero_pattern): Rewrite
the canonicalization of the args code based on e1/e2 being edges into
the join block.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/pr123645-1.c: New test.
* gcc.dg/torture/pr123645-2.c: New test.
Signed-off-by: Andrew Pinski <[email protected]>
---
gcc/testsuite/gcc.dg/torture/pr123645-1.c | 24 +++++++++++++++++
gcc/testsuite/gcc.dg/torture/pr123645-2.c | 24 +++++++++++++++++
gcc/tree-ssa-phiopt.cc | 32 ++++++++++++++++++-----
3 files changed, 74 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr123645-1.c
create mode 100644 gcc/testsuite/gcc.dg/torture/pr123645-2.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr123645-1.c
b/gcc/testsuite/gcc.dg/torture/pr123645-1.c
new file mode 100644
index 00000000000..c183cd31d41
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr123645-1.c
@@ -0,0 +1,24 @@
+/* { dg-do run } */
+
+/* PR tree-optimization/123645 */
+/* Phi-opt was transforming f into __builtin_popcount which was incorrect. */
+
+__attribute__((noinline))
+int f(unsigned a)
+{
+ return a < 1 ? __builtin_popcount(a) : 0;
+}
+
+int main()
+{
+ if (f(1) != 0)
+ __builtin_abort();
+ if (f(0) != 0)
+ __builtin_abort();
+ if (f(2) != 0)
+ __builtin_abort();
+ if (f(3) != 0)
+ __builtin_abort();
+ if (f(-1) != 0)
+ __builtin_abort();
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr123645-2.c
b/gcc/testsuite/gcc.dg/torture/pr123645-2.c
new file mode 100644
index 00000000000..8c488acfbec
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr123645-2.c
@@ -0,0 +1,24 @@
+/* { dg-do run } */
+
+/* PR tree-optimization/123645 */
+/* Phi-opt was transforming f into __builtin_bswap which was incorrect. */
+
+__attribute__((noinline))
+int f(unsigned a)
+{
+ return a < 1 ? __builtin_bswap32(a) : 0;
+}
+
+int main()
+{
+ if (f(1) != 0)
+ __builtin_abort();
+ if (f(0) != 0)
+ __builtin_abort();
+ if (f(2) != 0)
+ __builtin_abort();
+ if (f(3) != 0)
+ __builtin_abort();
+ if (f(-1) != 0)
+ __builtin_abort();
+}
diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
index 9ce24067377..167b86b3acc 100644
--- a/gcc/tree-ssa-phiopt.cc
+++ b/gcc/tree-ssa-phiopt.cc
@@ -2627,16 +2627,36 @@ cond_removal_in_builtin_zero_pattern (basic_block
cond_bb,
|| arg != gimple_cond_lhs (cond))
return false;
- /* Canonicalize. */
- if ((e2->flags & EDGE_TRUE_VALUE
- && gimple_cond_code (cond) == NE_EXPR)
- || (e1->flags & EDGE_TRUE_VALUE
- && gimple_cond_code (cond) == EQ_EXPR))
+ edge true_edge, false_edge;
+ /* We need to know which is the true edge and which is the false
+ edge so that we know when to invert the condition below. */
+ extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
+
+ /* Forward the edges over the middle basic block. */
+ if (true_edge->dest == middle_bb)
+ true_edge = EDGE_SUCC (true_edge->dest, 0);
+ if (false_edge->dest == middle_bb)
+ false_edge = EDGE_SUCC (false_edge->dest, 0);
+
+ /* Canonicalize the args with respect to the edges,
+ arg0 is from the true edge and arg1 is from the
+ false edge.
+ That is `cond ? arg0 : arg1`.*/
+ if (true_edge == e1)
+ gcc_assert (false_edge == e2);
+ else
{
+ gcc_assert (false_edge == e1);
+ gcc_assert (true_edge == e2);
std::swap (arg0, arg1);
- std::swap (e1, e2);
}
+ /* Canonicalize the args such that we get:
+ `arg != 0 ? arg0 : arg1`. So swap arg0/arg1
+ around if cond was an equals. */
+ if (gimple_cond_code (cond) == EQ_EXPR)
+ std::swap (arg0, arg1);
+
/* Check PHI arguments. */
if (lhs != arg0
|| TREE_CODE (arg1) != INTEGER_CST)
--
2.43.0
