[Bug target/40487] New: Extra zero extensions produced for ARM.

[ramana at gcc dot gnu dot org]

A colleague at ARM found this a couple of days back. 

With trunk as of a few days back configured for arm-none-eabi for cortex-a8


typedef unsigned short ushort;
typedef unsigned char uchar;

ushort foo(uchar data, uchar data1, uchar data2)
{
  uchar x = (uchar)(data);
  x ^= (x + 5); 
  x ^= (x << 2); 
  x ^= (x << 1); 
  return x;
}


foo:
        @ args = 0, pretend = 0, frame = 0
        @ frame_needed = 0, uses_anonymous_args = 0
        @ link register save eliminated.
        add     r3, r0, #5
        eor     r0, r3, r0
        uxtb    r0, r0   //redundant
        eor     r0, r0, r0, lsl #2
        uxtb    r0, r0   // redundant
        eor     r0, r0, r0, lsl #1
        uxtb    r0, r0
        bx      lr


-- 
           Summary: Extra zero extensions produced for ARM.
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ramana at gcc dot gnu dot org
 GCC build triplet: x86_64-linux
  GCC host triplet: x86_64-linux
GCC target triplet: arm-eabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40487