re PR tree-optimization/51938 (missed optimization: 2 comparisons)

2012-08-06 Marc Glisse <marc.glisse@inria.fr>

gcc/
	PR tree-optimization/51938
	PR tree-optimization/52005
	* tree-ssa-ifcombine.c (ifcombine_ifandif): New parameters for
	inverted conditions.
	(ifcombine_iforif): Remove, merge code into ifcombine_ifandif.
	(tree_ssa_ifcombine_bb): Update calls to the above. Detect !a&&b
	and !a||b patterns.

gcc/testsuite/
	PR tree-optimization/51938
	PR tree-optimization/52005
	* gcc.dg/tree-ssa/ssa-ifcombine-8.c: New testcase.
	* gcc.dg/tree-ssa/ssa-ifcombine-9.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-10.c: Likewise.
	* gcc.dg/tree-ssa/ssa-ifcombine-11.c: Likewise.

From-SVN: r190184

gcc/ChangeLog

+2012-08-06  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR tree-optimization/51938
+	PR tree-optimization/52005
+	* tree-ssa-ifcombine.c (ifcombine_ifandif): New parameters for
+	inverted conditions.
+	(ifcombine_iforif): Remove, merge code into ifcombine_ifandif.
+	(tree_ssa_ifcombine_bb): Update calls to the above. Detect !a&&b
+	and !a||b patterns.
+
 2012-08-06  Olivier Hainque  <hainque@adacore.com>
 
 	* tree-emutls.c (new_emutls_decl): When a var_section is requested by

gcc/testsuite/ChangeLog

+2012-08-06  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR tree-optimization/51938
+	PR tree-optimization/52005
+	* gcc.dg/tree-ssa/ssa-ifcombine-8.c: New testcase.
+	* gcc.dg/tree-ssa/ssa-ifcombine-9.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-ifcombine-10.c: Likewise.
+	* gcc.dg/tree-ssa/ssa-ifcombine-11.c: Likewise.
+
 2012-08-06  Dodji Seketeli  <dodji@redhat.com>
 
 	Avoid crashing on erroneous static_assert usage

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-10.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+/* Testcase for PR31657.  */
+
+int f(int x, int a, int b)
+{
+  int t = 0;
+  int c = 1 << a;
+  if (!(x & 1))
+    t = 0;
+  else
+    if (x & (1 << 2))
+      t = 3;
+    else
+      t = 0;
+  return t;
+}
+/* { dg-final { scan-tree-dump "& 5" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-11.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+/* Testcase for PR31657.  */
+int g(void);
+int f(int x, int a, int b)
+{
+  int t = 0;
+  int c = 1 << a;
+  if (!(x & 1))
+    t = 0;
+  else
+    if (x & (1 << 2))
+      t = g();
+    else
+      t = 0;
+  return t;
+}
+
+/* { dg-final { scan-tree-dump "& 5" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-8.c

+/* { dg-do compile } */
+/* { dg-options "-O -fno-trapping-math -fdump-tree-ifcombine" } */
+
+double test1 (double i, double j)
+{
+  if (i >= j)
+    if (i <= j)
+      goto plif;
+    else
+      goto plouf;
+  else
+    goto plif;
+
+plif:
+  return 0;
+plouf:
+  return -1;
+}
+
+/* The above should be optimized to a i > j test by ifcombine.
+   The transformation would also be legal with -ftrapping-math.
+   Instead we get u<=, which is acceptable with -fno-trapping-math.  */
+
+/* { dg-final { scan-tree-dump " u<= " "ifcombine" } } */
+/* { dg-final { cleanup-tree-dump "ifcombine" } } */

gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-9.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-trapping-math -fdump-tree-ifcombine" } */
+
+void f ();
+enum Sign { NEG=-1, ZERO, POS };
+
+static inline enum Sign sign (double x)
+{
+  if (x > 0) return POS;
+  if (x < 0) return NEG;
+  return ZERO;
+}
+void g (double x)
+{
+  if (sign (x) == NEG) f();
+}
+
+/* The above should be optimized to x < 0 by ifcombine.
+   The transformation would also be legal with -ftrapping-math.  */
+
+/* { dg-final { scan-tree-dump "optimizing.* < " "ifcombine" } } */
+/* { dg-final { cleanup-tree-dump "ifcombine" } } */