gcc:

2006-01-11  Paolo Bonzini  <bonzini@gnu.org>

	PR tree-optimization/23109
	PR tree-optimization/23948
	PR tree-optimization/24123

	* Makefile.in (tree-ssa-math-opts.o): Adjust dependencies.
        * tree-cfg.c (single_noncomplex_succ): New.
        * tree-flow.h (single_noncomplex_succ): Declare it.
        * tree-ssa-math-opts.c (enum place_reciprocal): Remove.
        * tree-ssa-math-opts.c (enum place_reciprocal): Remove.
        (struct occurrence, occ_head, occ_pool, is_divide_by, compute_merit,
	insert_bb, register_division_in, insert_reciprocals,
	replace_reciprocal, free_bb): New.
        (execute_cse_reciprocals_1): Rewritten.
        (execute_cse_reciprocals): Adjust calls to execute_cse_reciprocals_1.
        Do not commit any edge insertion.  Always compute dominators and
        create the allocation pool.
        * target-def.h (TARGET_MIN_DIVISIONS_FOR_RECIP_MUL): New.
	* target.h (struct gcc_target): Add min_divistions_for_recip_mul.
	* targhooks.c (default_min_divistions_for_recip_mul): New.
	* targhooks.h (default_min_divistions_for_recip_mul): New prototype.
        * passes.c (init_optimization_passes): Run recip after tree loop
        optimizations.
        * doc/tm.texi (Misc): Document TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.

gcc/testsuite:
2006-01-11  Paolo Bonzini  <bonzini@gnu.org>
        
        PR tree-optimization/23109
        PR tree-optimization/23948
        PR tree-optimization/24123

        * gcc.dg/tree-ssa/recip-3.c, gcc.dg/tree-ssa/recip-4.c,
        gcc.dg/tree-ssa/recip-5.c, gcc.dg/tree-ssa/recip-6.c,
        gcc.dg/tree-ssa/recip-7.c, gcc.dg/tree-ssa/pr23109.c,
        g++.dg/tree-ssa/pr23948.C: New testcases.
        * gcc.dg/tree-ssa/recip-2.c, gcc.dg/tree-ssa/pr23234.c: Provide
	three divisions in order to do the optimization.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@109578 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 205 insertions, 4 deletions

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr23109.c b/gcc/testsuite/gcc.dg/tree-ssa/pr23109.c
new file mode 100644
index 00000000000..e121a553833
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr23109.c
@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funsafe-math-optimizations -fdump-tree-recip -fdump-tree-lim" } */
+
+double F[2] = { 0., 0. }, e = 0.;
+
+int main()
+{
+	int i;
+	double E, W, P, d;
+
+        /* make sure the program crashes on FP exception */
+        unsigned short int Mask;
+
+	W = 1.;
+	d = 2.*e;
+	E = 1. - d;
+
+	for( i=0; i < 2; i++ )
+		if( d > 0.01 )
+		{
+			P = ( W < E ) ? (W - E)/d : (E - W)/d;
+			F[i] += P;
+		}
+
+	return 0;
+}
+
+/* LIM only performs the transformation in the no-trapping-math case.  In
+   the future we will do it for trapping-math as well in recip, check that
+   this is not wrongly optimized.  */
+/* { dg-final { scan-tree-dump-not "reciptmp" "lim" } } */
+/* { dg-final { scan-tree-dump-not "reciptmp" "recip" } } */
+/* { dg-final { cleanup-tree-dump "recip" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c b/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c
index bd0b62b558f..3a3869815c8 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr23234.c
@@ -9,6 +9,7 @@ double
 f1 (double a, double b, double c)
 {
   double y0;
+  double y1;
 
   if (a == 0.0)
     {
@@ -16,7 +17,8 @@ f1 (double a, double b, double c)
       return y0;
     }
   y0 = c / b;
-  return y0;
+  y1 = a / b;
+  return y0 * y1;
 }
 
 /* Labels may end up in the middle of a block.  Also bad.  */
@@ -24,6 +26,7 @@ double
 f2 (double a, double b, double c)
 {
   double y0;
+  double y1;
 
 a_label:
 another_label:
@@ -33,7 +36,8 @@ another_label:
       return y0;
     }
   y0 = c / b;
-  return y0;
+  y1 = a / b;
+  return y0 * y1;
 }
 
 /* Uses must still be dominated by their defs.  */
@@ -41,6 +45,7 @@ double
 f3 (double a, double b, double c)
 {
   double y0;
+  double y1;
 
   y0 = -c / b;
   if (a == 0.0)
@@ -48,5 +53,6 @@ f3 (double a, double b, double c)
       return y0;
     }
   y0 = c / b;
-  return y0;
+  y1 = a / b;
+  return y0 * y1;
 }
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-2.c b/gcc/testsuite/gcc.dg/tree-ssa/recip-2.c
index 7d0e97ae371..af628053ad5 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/recip-2.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-2.c
@@ -10,14 +10,19 @@ float e(float a, float b, float c, float d, float e, float f)
     }
 
   /* The PHI nodes for these divisions should be combined.  */
+  d = d / a;
   e = e / a;
   f = f / a;
   
   a = a / c;
   b = b / c;
 
-  return a + b + e + f;
+  /* This should not be left as a multiplication.  */
+  c = 1 / c;
+
+  return a + b + c + d + e + f;
 }
 
 /* { dg-final { scan-tree-dump-times " / " 2 "recip" } } */
+/* { dg-final { scan-tree-dump-times " \\* " 5 "recip" } } */
 /* { dg-final { cleanup-tree-dump "recip" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c b/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c
new file mode 100644
index 00000000000..45c8db148ac
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-3.c
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fno-trapping-math -funsafe-math-optimizations -fdump-tree-recip" } */
+
+double F[2] = { 0.0, 0.0 }, e;
+
+/* In this case the optimization is interesting.  */
+float h ()
+{
+	int i;
+	double E, W, P, d;
+
+	W = 1.;
+	d = 2.*e;
+	E = 1. - d;
+
+	for( i=0; i < 2; i++ )
+		if( d > 0.01 )
+		{
+			P = ( W < E ) ? (W - E)/d : (E - W)/d;
+			F[i] += P;
+		}
+
+	F[0] += E / d;
+}
+
+/* { dg-final { scan-tree-dump-times " / " 1 "recip" } } */
+/* { dg-final { cleanup-tree-dump "recip" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-4.c b/gcc/testsuite/gcc.dg/tree-ssa/recip-4.c
new file mode 100644
index 00000000000..20d7681d28d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-4.c
@@ -0,0 +1,45 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fno-trapping-math -funsafe-math-optimizations -fdump-tree-recip" } */
+
+/* based on the test case in pr23109 */
+
+double F[2] = { 0., 0. }, e = 0.;
+
+/* Nope, we cannot prove the optimization is worthwhile in this case.  */
+void f ()
+{
+	int i;
+	double E, W, P, d;
+
+	W = 1.;
+	d = 2.*e;
+	E = 1. - d;
+
+	if( d > 0.01 )
+	{
+		P = ( W < E ) ? (W - E)/d : (E - W)/d;
+		F[i] += P;
+	}
+}
+
+/* We also cannot prove the optimization is worthwhile in this case.  */
+float g ()
+{
+	int i;
+	double E, W, P, d;
+
+	W = 1.;
+	d = 2.*e;
+	E = 1. - d;
+
+	if( d > 0.01 )
+	{
+		P = ( W < E ) ? (W - E)/d : (E - W)/d;
+		F[i] += P;
+	}
+
+	return 1.0 / d;
+}
+
+/* { dg-final { scan-tree-dump-not "reciptmp" "recip" } } */
+/* { dg-final { cleanup-tree-dump "recip" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-5.c b/gcc/testsuite/gcc.dg/tree-ssa/recip-5.c
new file mode 100644
index 00000000000..bcbd1839cbc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-5.c
@@ -0,0 +1,31 @@
+/* { dg-options "-O1 -funsafe-math-optimizations -ftrapping-math -fdump-tree-recip -fdump-tree-optimized" } */
+/* { dg-do compile } */
+
+/* Test the reciprocal optimizations together with trapping math.  */
+
+extern int f2();
+
+double f1(double y, double z, double w, double j, double k)
+{
+  double b, c, d, e, f, g;
+
+  if (f2 ())
+    /* inserts one division here */
+    b = 1 / y, c = z / y, d = j / y;
+  else
+    /* one division here */
+    b = 3 / y, c = w / y, d = k / y;
+
+  /* and one here, that should be removed afterwards but is not right now */
+  e = b / y;
+  f = c / y;
+  g = d / y;
+
+  return e + f + g;
+}
+
+/* { dg-final { scan-tree-dump-times " / " 3 "recip" } } */
+/* { dg-final { scan-tree-dump-times " / " 2 "optimized" { xfail *-*-* } } } */
+/* { dg-final { cleanup-tree-dump "recip" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-6.c b/gcc/testsuite/gcc.dg/tree-ssa/recip-6.c
new file mode 100644
index 00000000000..60fefd01da5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-6.c
@@ -0,0 +1,26 @@
+/* { dg-options "-O1 -funsafe-math-optimizations -fno-trapping-math -fdump-tree-recip" } */
+/* { dg-do compile } */
+
+/* Test inserting in a block that does not contain a division.  */
+
+extern int f2();
+
+double f1(double y, double z, double w)
+{
+  double b, c, d, e, f;
+
+  if (g ())
+    b = 1 / y, c = z / y;
+  else
+    b = 3 / y, c = w / y;
+
+  d = b / y;
+  e = c / y;
+  f = 1 / y;
+
+  return d + e + f;
+}
+
+/* { dg-final { scan-tree-dump-times " / " 1 "recip" } } */
+/* { dg-final { cleanup-tree-dump "recip" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/recip-7.c b/gcc/testsuite/gcc.dg/tree-ssa/recip-7.c
new file mode 100644
index 00000000000..af1bf3c008b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/recip-7.c
@@ -0,0 +1,27 @@
+/* { dg-options "-O1 -funsafe-math-optimizations -fno-trapping-math -fdump-tree-recip" } */
+/* { dg-do compile } */
+
+/* Test inserting in a block that does not contain a division.  */
+
+extern double h();
+
+double f(int x, double z, double w)
+{
+  double b, c, d, e, f;
+  double y = h ();
+
+  if (x)
+    b = 1 / y, c = z / y;
+  else
+    b = 3 / y, c = w / y;
+
+  d = b / y;
+  e = c / y;
+  f = 1 / y;
+
+  return d + e + f;
+}
+
+/* { dg-final { scan-tree-dump-times " / " 1 "recip" } } */
+/* { dg-final { cleanup-tree-dump "recip" } } */
+