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@@ -1,188 +0,0 @@
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-Index: gcc-4.3.2/gcc/tree-scalar-evolution.c
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-===================================================================
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---- gcc-4.3.2.orig/gcc/tree-scalar-evolution.c 2009-01-28 10:14:37.000000000 +0100
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-+++ gcc-4.3.2/gcc/tree-scalar-evolution.c 2009-01-28 10:17:50.000000000 +0100
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-@@ -2716,6 +2716,50 @@
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- scalar_evolution_info = NULL;
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- }
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-
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-+/* Returns true if the expression EXPR is considered to be too expensive
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-+ for scev_const_prop. */
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-+
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-+bool
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-+expression_expensive_p (tree expr)
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-+{
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-+ enum tree_code code;
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-+
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-+ if (is_gimple_val (expr))
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-+ return false;
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-+
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-+ code = TREE_CODE (expr);
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-+ if (code == TRUNC_DIV_EXPR
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-+ || code == CEIL_DIV_EXPR
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-+ || code == FLOOR_DIV_EXPR
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-+ || code == ROUND_DIV_EXPR
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-+ || code == TRUNC_MOD_EXPR
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-+ || code == CEIL_MOD_EXPR
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-+ || code == FLOOR_MOD_EXPR
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-+ || code == ROUND_MOD_EXPR
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-+ || code == EXACT_DIV_EXPR)
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-+ {
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-+ /* Division by power of two is usually cheap, so we allow it.
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-+ Forbid anything else. */
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-+ if (!integer_pow2p (TREE_OPERAND (expr, 1)))
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-+ return true;
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-+ }
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-+
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-+ switch (TREE_CODE_CLASS (code))
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-+ {
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-+ case tcc_binary:
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-+ case tcc_comparison:
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-+ if (expression_expensive_p (TREE_OPERAND (expr, 1)))
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-+ return true;
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-+
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-+ /* Fallthru. */
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-+ case tcc_unary:
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-+ return expression_expensive_p (TREE_OPERAND (expr, 0));
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-+
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-+ default:
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-+ return true;
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-+ }
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-+}
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-+
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- /* Replace ssa names for that scev can prove they are constant by the
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- appropriate constants. Also perform final value replacement in loops,
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- in case the replacement expressions are cheap.
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-@@ -2802,12 +2846,6 @@
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- continue;
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-
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- niter = number_of_latch_executions (loop);
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-- /* We used to check here whether the computation of NITER is expensive,
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-- and avoided final value elimination if that is the case. The problem
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-- is that it is hard to evaluate whether the expression is too
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-- expensive, as we do not know what optimization opportunities the
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-- the elimination of the final value may reveal. Therefore, we now
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-- eliminate the final values of induction variables unconditionally. */
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- if (niter == chrec_dont_know)
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- continue;
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-
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-@@ -2838,7 +2876,15 @@
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- /* Moving the computation from the loop may prolong life range
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- of some ssa names, which may cause problems if they appear
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- on abnormal edges. */
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-- || contains_abnormal_ssa_name_p (def))
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-+ || contains_abnormal_ssa_name_p (def)
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-+ /* Do not emit expensive expressions. The rationale is that
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-+ when someone writes a code like
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-+
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-+ while (n > 45) n -= 45;
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-+
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-+ he probably knows that n is not large, and does not want it
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-+ to be turned into n %= 45. */
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-+ || expression_expensive_p (def))
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- continue;
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-
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- /* Eliminate the PHI node and replace it by a computation outside
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-Index: gcc-4.3.2/gcc/tree-scalar-evolution.h
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-===================================================================
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---- gcc-4.3.2.orig/gcc/tree-scalar-evolution.h 2009-01-28 10:22:47.000000000 +0100
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-+++ gcc-4.3.2/gcc/tree-scalar-evolution.h 2009-01-28 10:23:10.000000000 +0100
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-@@ -35,6 +35,7 @@
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- extern void scev_analysis (void);
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- unsigned int scev_const_prop (void);
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-
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-+bool expression_expensive_p (tree);
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- extern bool simple_iv (struct loop *, tree, tree, affine_iv *, bool);
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-
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- /* Returns the loop of the polynomial chrec CHREC. */
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-Index: gcc-4.3.2/gcc/testsuite/gcc.dg/pr34027-1.c
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-===================================================================
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---- gcc-4.3.2.orig/gcc/testsuite/gcc.dg/pr34027-1.c 2009-01-28 10:24:09.000000000 +0100
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-+++ gcc-4.3.2/gcc/testsuite/gcc.dg/pr34027-1.c 2009-01-28 10:24:43.000000000 +0100
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-@@ -8,5 +8,9 @@
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- return ns;
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- }
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-
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--/* { dg-final { scan-tree-dump "ns % 10000" "optimized" } } */
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-+/* This test was originally introduced to test that we transform
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-+ to ns % 10000. See the discussion of PR 32044 why we do not do
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-+ that anymore. */
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-+/* { dg-final { scan-tree-dump-times "%" 0 "optimized" } } */
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-+/* { dg-final { scan-tree-dump-times "/" 0 "optimized" } } */
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- /* { dg-final { cleanup-tree-dump "optimized" } } */
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-Index: gcc-4.3.2/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c
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-===================================================================
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---- /dev/null 1970-01-01 00:00:00.000000000 +0000
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-+++ gcc-4.3.2/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c 2009-01-28 10:25:50.000000000 +0100
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-@@ -0,0 +1,55 @@
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-+/* { dg-do compile } */
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-+/* { dg-options "-O2 -fdump-tree-empty -fdump-tree-final_cleanup" } */
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-+
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-+int foo (int n)
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-+{
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-+ while (n >= 45)
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-+ n -= 45;
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-+
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-+ return n;
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-+}
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-+
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-+int bar (int n)
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-+{
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-+ while (n >= 64)
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-+ n -= 64;
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-+
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-+ return n;
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-+}
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-+
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-+int bla (int n)
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-+{
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-+ int i = 0;
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-+
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-+ while (n >= 45)
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-+ {
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-+ i++;
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-+ n -= 45;
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-+ }
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-+
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-+ return i;
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-+}
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-+
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-+int baz (int n)
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-+{
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-+ int i = 0;
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-+
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-+ while (n >= 64)
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-+ {
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-+ i++;
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-+ n -= 64;
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-+ }
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-+
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-+ return i;
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-+}
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-+
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-+/* The loops computing division/modulo by 64 should be eliminated. */
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-+/* { dg-final { scan-tree-dump-times "Removing empty loop" 2 "empty" } } */
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-+
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-+/* There should be no division/modulo in the final dump (division and modulo
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-+ by 64 are done using bit operations). */
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-+/* { dg-final { scan-tree-dump-times "/" 0 "final_cleanup" } } */
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-+/* { dg-final { scan-tree-dump-times "%" 0 "final_cleanup" } } */
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-+
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-+/* { dg-final { cleanup-tree-dump "empty" } } */
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-+/* { dg-final { cleanup-tree-dump "final_cleanup" } } */
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-Index: gcc-4.3.2/gcc/tree-ssa-loop-ivopts.c
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-===================================================================
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---- gcc-4.3.2.orig/gcc/tree-ssa-loop-ivopts.c 2009-01-28 10:26:04.000000000 +0100
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-+++ gcc-4.3.2/gcc/tree-ssa-loop-ivopts.c 2009-01-28 10:27:09.000000000 +0100
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-@@ -3778,7 +3778,12 @@
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- return false;
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-
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- cand_value_at (loop, cand, use->stmt, nit, &bnd);
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-+
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- *bound = aff_combination_to_tree (&bnd);
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-+ /* It is unlikely that computing the number of iterations using division
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-+ would be more profitable than keeping the original induction variable. */
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-+ if (expression_expensive_p (*bound))
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-+ return false;
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- return true;
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- }
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Peter Korsgaard