re PR tree-optimization/23234 (ICE in verify_flow_info())

gcc/
	PR tree-optimization/23234
	* tree-ssa-math-opts.c (place_reciprocal): New enum.
	(execute_cse_reciprocals_1): Replace the 'phi' argument with an
	argument of the new enum.
	(execute_cse_reciprocals): Add reciprocals for function arguments
	on the unique successor edge of the entry block.  Update other calls
	to execute_cse_reciprocals_1.

testsuite/
	PR tree-optimization/23234
	* gcc.dg/tree-ssa/pr23234.c: New test.

From-SVN: r102895

1 files changed, 52 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c b/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c
new file mode 100644
index 0000000..bd0b62b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c
@@ -0,0 +1,52 @@
+/* The problem in this PR was mostly finding a suitable place to insert
+   the reciprocals of the function arguments.  This test case tries to
+   test three possible ways of how this may go wrong.  */
+/* { dg-options "-O2 -ffast-math" } */
+/* { dg-do compile } */
+
+/* The original test case.  */
+double
+f1 (double a, double b, double c)
+{
+  double y0;
+
+  if (a == 0.0)
+    {
+      y0 = -c / b;
+      return y0;
+    }
+  y0 = c / b;
+  return y0;
+}
+
+/* Labels may end up in the middle of a block.  Also bad.  */
+double
+f2 (double a, double b, double c)
+{
+  double y0;
+
+a_label:
+another_label:
+  if (a == 0.0)
+    {
+      y0 = -c / b;
+      return y0;
+    }
+  y0 = c / b;
+  return y0;
+}
+
+/* Uses must still be dominated by their defs.  */
+double
+f3 (double a, double b, double c)
+{
+  double y0;
+
+  y0 = -c / b;
+  if (a == 0.0)
+    {
+      return y0;
+    }
+  y0 = c / b;
+  return y0;
+}