fold-const.c (fold_range_test): Use RANGE_TEST_NON_SHORT_CIRCUIT macro defaulting...

        * 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

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9f7fa317af89dc2578d9034b274eae774898ee4d..722ce66ba2cf05572b3fd66184301cf3bd6662ed 100644 (file)
--- 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 b566619e7a917b7fbb9eca72c53f208655c49683..994f67af8bee356bf35ea9cdd34205bb0d8e3310 100644 (file)
--- 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 092e400dcec14bf537364d89f46b8116ef3fa880..88ad237291a1ae5d73783c76f87cf4a16bd9dc17 100644 (file)
--- 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 146f40f97ac820b0f295b2a71556690673446c1f..eb65795e913e9eb6c3a6360568c3f393dc8beacb 100644 (file)
--- 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;
 }
 \f
+#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)