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diff src/share/vm/opto/divnode.cpp @ 1154:174ade00803b

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6910484: incorrect integer optimization (loosing and op-r in a given example) Summary: Remove AND operation only if mask is equal to shift. Reviewed-by: never
author kvn
date Fri, 08 Jan 2010 09:51:24 -0800
parents cecd04fc6f93
children c18cbe5936b8
line wrap: on
line diff
--- a/src/share/vm/opto/divnode.cpp	Fri Jan 08 09:42:31 2010 -0800
+++ b/src/share/vm/opto/divnode.cpp	Fri Jan 08 09:51:24 2010 -0800
@@ -114,7 +114,8 @@
       if( andconi_t && andconi_t->is_con() ) {
         jint andconi = andconi_t->get_con();
         if( andconi < 0 && is_power_of_2(-andconi) && (-andconi) >= d ) {
-          dividend = dividend->in(1);
+          if( (-andconi) == d ) // Remove AND if it clears bits which will be shifted
+            dividend = dividend->in(1);
           needs_rounding = false;
         }
       }
@@ -356,7 +357,8 @@
       if( andconl_t && andconl_t->is_con() ) {
         jlong andconl = andconl_t->get_con();
         if( andconl < 0 && is_power_of_2_long(-andconl) && (-andconl) >= d ) {
-          dividend = dividend->in(1);
+          if( (-andconl) == d ) // Remove AND if it clears bits which will be shifted
+            dividend = dividend->in(1);
           needs_rounding = false;
         }
       }