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Date: Mon, 08 May 2006 19:28:00 -0000
Subject: [Bug tree-optimization/27504]  New: x && (x & y) not optimized to x & y
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From: "falk at debian dot org" <gcc-bugzilla@gcc.gnu.org>
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Example:

falk@juist:/tmp% cat test.c 
int f(int x) { return x && (x & 0x55); }

falk@juist:/tmp% gcc -c -O3  test.c && objdump -d test.o
0000000000000000 <f>:
   0:   00 04 ff 47     clr     v0
   4:   02 00 00 e6     beq     a0,10 <f+0x10>
   8:   01 b0 0a 46     and     a0,0x55,t0
   c:   a0 03 e1 43     cmpult  zero,t0,v0
  10:   01 80 fa 6b     ret


-- 
           Summary: x && (x & y) not optimized to x & y
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: falk at debian dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504