2004-03-05 Paolo Bonzini <bonzini@gnu.org>

	* simplify-rtx.c (simplify_relational_operation): If
        flag_wrapv is set, do not move terms between the two
        side of a relational operator.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@78962 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0023618..723492a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,11 @@
 2004-03-05  Paolo Bonzini  <bonzini@gnu.org>
 
+       * simplify-rtx.c (simplify_relational_operation): If
+       flag_wrapv is set, do not move terms between the two
+       side of a relational operator.
+
+2004-03-05  Paolo Bonzini  <bonzini@gnu.org>
+
        * rtlanal.c: Include target.h and output.h
        (rtx_cost, address_cost, default_address_cost): Move from...
        * cse.c (rtx_cost, address_cost, default_address_cost):

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index bae37f8..b86a8b2 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -2559,9 +2559,10 @@ simplify_relational_operation (enum rtx_code code, enum machine_mode mode,
      If CODE is an unsigned comparison, then we can never do this optimization,
      because it gives an incorrect result if the subtraction wraps around zero.
      ANSI C defines unsigned operations such that they never overflow, and
-     thus such cases can not be ignored.  */
+     thus such cases can not be ignored; but we cannot do it even for
+     signed comparisons for languages such as Java, so test flag_wrapv.  */
 
-  if (INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx
+  if (!flag_wrapv && INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx
       && ! ((GET_CODE (op0) == REG || GET_CODE (trueop0) == CONST_INT)
            && (GET_CODE (op1) == REG || GET_CODE (trueop1) == CONST_INT))
       && 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1))