From 771f882e18593bf51b526dc3cc75a41aaec2313c Mon Sep 17 00:00:00 2001
From: Zdenek Dvorak <ook@ucw.cz>
Date: Fri, 12 Dec 2008 21:32:47 +0100
Subject: re PR tree-optimization/32044 (final value replacement too aggressive
 for e.g. targets with no native div/mod insns)

	PR tree-optimization/32044
	* tree-scalar-evolution.h (expression_expensive_p): Declare.
	* tree-scalar-evolution.c (expression_expensive_p): New function.
	(scev_const_prop): Avoid introducing expensive expressions.
	* tree-ssa-loop-ivopts.c (may_eliminate_iv): Ditto.

	* gcc.dg/pr34027-1.c: Change outcome.
	* gcc.dg/tree-ssa/pr32044.c: New test.

From-SVN: r142719
---
 gcc/testsuite/gcc.dg/pr34027-1.c        |  6 +++-
 gcc/testsuite/gcc.dg/tree-ssa/pr32044.c | 55 +++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr32044.c

(limited to 'gcc/testsuite/gcc.dg')

diff --git a/gcc/testsuite/gcc.dg/pr34027-1.c b/gcc/testsuite/gcc.dg/pr34027-1.c
index 532e497..8e8872a 100644
--- a/gcc/testsuite/gcc.dg/pr34027-1.c
+++ b/gcc/testsuite/gcc.dg/pr34027-1.c
@@ -8,5 +8,9 @@ unsigned long foobar(unsigned long ns)
   return ns;
 }
 
-/* { dg-final { scan-tree-dump "ns % 10000" "optimized" } } */
+/* This test was originally introduced to test that we transform
+   to ns % 10000.  See the discussion of PR 32044 why we do not do
+   that anymore.  */
+/* { dg-final { scan-tree-dump-times "%" 0 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "/" 0 "optimized" } } */
 /* { dg-final { cleanup-tree-dump "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c b/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c
new file mode 100644
index 0000000..0c1a582
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c
@@ -0,0 +1,55 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-empty -fdump-tree-final_cleanup" } */
+
+int foo (int n)
+{
+  while (n >= 45)
+    n -= 45;
+
+  return n;
+}
+
+int bar (int n)
+{
+  while (n >= 64)
+    n -= 64;
+
+  return n;
+}
+
+int bla (int n)
+{
+  int i = 0;
+
+  while (n >= 45)
+    {
+      i++;
+      n -= 45;
+    }
+
+  return i;
+}
+
+int baz (int n)
+{
+  int i = 0;
+
+  while (n >= 64)
+    {
+      i++;
+      n -= 64;
+    }
+
+  return i;
+}
+
+/* The loops computing division/modulo by 64 should be eliminated.  */
+/* { dg-final { scan-tree-dump-times "Removing empty loop" 2 "empty" } } */
+
+/* There should be no division/modulo in the final dump (division and modulo
+   by 64 are done using bit operations).  */
+/* { dg-final { scan-tree-dump-times "/" 0 "final_cleanup" } } */
+/* { dg-final { scan-tree-dump-times "%" 0 "final_cleanup" } } */
+
+/* { dg-final { cleanup-tree-dump "empty" } } */
+/* { dg-final { cleanup-tree-dump "final_cleanup" } } */
-- 
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