From 85e50b6ba8ca2221593838878ab8d804b37faf44 Mon Sep 17 00:00:00 2001
From: David Edelsohn <edelsohn@gnu.org>
Date: Tue, 22 Apr 2003 15:01:18 +0000
Subject: [PATCH] fold-const.c (fold_range_test): Use
RANGE_TEST_NON_SHORT_CIRCUIT macro defaulting to original BRANCH_COST
heuristic.
* fold-const.c (fold_range_test): Use RANGE_TEST_NON_SHORT_CIRCUIT
macro defaulting to original BRANCH_COST heuristic.
* doc/tm.texi (RANGE_TEST_NON_SHORT_CIRCUIT): Document.
* config/rs6000/rs6000.h (RANGE_TEST_NON_SHORT_CIRCUIT): Define.
From-SVN: r65942
---
gcc/ChangeLog | 8 ++++++++
gcc/config/rs6000/rs6000.h | 4 ++++
gcc/doc/tm.texi | 6 ++++++
gcc/fold-const.c | 6 +++++-
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9f7fa317af89..722ce66ba2cf 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2003-04-22 David Edelsohn <edelsohn@gnu.org>
+
+ * fold-const.c (fold_range_test): Use RANGE_TEST_NON_SHORT_CIRCUIT
+ macro defaulting to original BRANCH_COST heuristic.
+ * doc/tm.texi (RANGE_TEST_NON_SHORT_CIRCUIT): Document.
+
+ * config/rs6000/rs6000.h (RANGE_TEST_NON_SHORT_CIRCUIT): Define.
+
2003-04-22 Aldy Hernandez <aldyh@redhat.com>
* config/rs6000/t-spe: Merge in t-fprules into file.
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index b566619e7a91..994f67af8bee 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -992,6 +992,10 @@ extern int rs6000_default_long_calls;
#define BRANCH_COST 3
+/* Override BRANCH_COST heuristic which empirically produces worse
+ performance for fold_range_test(). */
+
+#define RANGE_TEST_NON_SHORT_CIRCUIT 0
/* A fixed register used at prologue and epilogue generation to fix
addressing modes. The SPE needs heavy addressing fixes at the last
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 092e400dcec1..88ad237291a1 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -5529,6 +5529,12 @@ function address than to call an address kept in a register.
Define this macro if it is as good or better for a function to call
itself with an explicit address than to call an address kept in a
register.
+
+@findex RANGE_TEST_NON_SHORT_CIRCUIT
+@item RANGE_TEST_NON_SHORT_CIRCUIT
+Define this macro if a non-short-circuit operation produced by
+@samp{fold_range_test ()} is optimal. This macro defaults to true if
+@code{BRANCH_COST} is greater than or equal to the value 2.
@end table
@deftypefn {Target Hook} bool TARGET_RTX_COSTS (rtx @var{x}, int @var{code}, int @var{outer_code}, int *@var{total})
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 146f40f97ac8..eb65795e913e 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -3414,6 +3414,10 @@ merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
return 1;
}
+#ifndef RANGE_TEST_NON_SHORT_CIRCUIT
+#define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
+#endif
+
/* EXP is some logical combination of boolean tests. See if we can
merge it into some range test. Return the new tree if so. */
@@ -3450,7 +3454,7 @@ fold_range_test (exp)
/* On machines where the branch cost is expensive, if this is a
short-circuited branch and the underlying object on both sides
is the same, make a non-short-circuit operation. */
- else if (BRANCH_COST >= 2
+ else if (RANGE_TEST_NON_SHORT_CIRCUIT
&& lhs != 0 && rhs != 0
&& (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
|| TREE_CODE (exp) == TRUTH_ORIF_EXPR)
--
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