re PR tree-optimization/71026 (Missing division optimizations)

2017-09-15  Jackson Woodruff  <jackson.woodruff@arm.com>

	PR tree-optimization/71026
	* match.pd: Move RDIV patterns from fold-const.c
	* fold-const.c (distribute_real_division): Removed.
	(fold_binary_loc): Remove calls to distribute_real_divison.

	PR tree-optimization/71026
	* gcc/testsuire/gcc.dg/fold-div-1.c: Use -O1.

From-SVN: r252827

gcc/ChangeLog

+2017-09-15  Jackson Woodruff  <jackson.woodruff@arm.com>
+
+	PR tree-optimization/71026
+	* match.pd: Move RDIV patterns from fold-const.c
+	* fold-const.c (distribute_real_division): Removed.
+	(fold_binary_loc): Remove calls to distribute_real_divison.
+
 2017-09-15  Jakub Jelinek  <jakub@redhat.com>
 
 	* doc/invoke.texi: Document -std=c++17 and -std=gnu++17 and document

gcc/match.pd

@@ -3517,6 +3517,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
   (if (!HONOR_SNANS (type))
    @0))
 
+ (for op (plus minus)
+  /* Simplify (A / C) +- (B / C) -> (A +- B) / C.  */
+  (simplify
+   (op (rdiv @0 @1)
+       (rdiv @2 @1))
+   (rdiv (op @0 @2) @1)))
+
  /* Simplify sqrt(x) * sqrt(y) -> sqrt(x*y).  */
  (for root (SQRT CBRT)
   (simplify

gcc/testsuite/ChangeLog

+2017-09-15  Jackson Woodruff  <jackson.woodruff@arm.com>
+
+	PR tree-optimization/71026
+	* gcc/testsuire/gcc.dg/fold-div-1.c: Use -O1.
+
 2017-09-15  Jakub Jelinek  <jakub@redhat.com>
 
 	* lib/g++-dg.exp (g++-dg-runtest): Use 17 instead of 1z.

gcc/testsuite/gcc.dg/fold-div-1.c

 /* { dg-do compile } */
-/* { dg-options "-funsafe-math-optimizations -fdump-tree-gimple" } */
+/* { dg-options "-O1 -funsafe-math-optimizations -fdump-tree-gimple" } */
 
 float f(float x)
 {