[Bug c++/26445] New: SSE byte-by-byte load instruction fails to compile

["gchernis11 at msn dot com" <gcc-bugzilla@gcc.gnu.org>]

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Call to the following function ...


/*inline */ void ConvertFloatSSE(void *inBuff, void *outBuff, int len)
{
   unsigned char* inByteBuffer   = reinterpret_cast<unsigned char *>(inBuff);
   float*         outFloatBuffer = reinterpret_cast<float         *>(outBuff);

   for(int i = 0; i<len/4; i++)
   {
      __m128i register1 = _mm_set_epi8(
                                       *inByteBuffer    , *(inByteBuffer+ 1),
*(inByteBuffer+ 2), 0,
                                       *(inByteBuffer+3), *(inByteBuffer+ 4),
*(inByteBuffer+ 5), 0,
                                       *(inByteBuffer+6), *(inByteBuffer+ 7),
*(inByteBuffer+ 8), 0,
                                       *(inByteBuffer+9), *(inByteBuffer+10),
*(inByteBuffer+11), 0
                                      );
      __m128i register2 = _mm_srai_epi32  (register1, 8);
      __m128  register3 = _mm_cvtepi32_ps (register2);
                      _mm_store_ps    (outFloatBuffer, register3);
      outFloatBuffer += 4;
      inByteBuffer += 12;
   }
}

generates...
************************************************************************************************************************************
if g++ -DHAVE_CONFIG_H -I. -I/home/gchernis/tryswap/src -I.. -O1 -g0 -Wall
-march=opteron -MT tryswap.o -MD -MP -MF ".deps/tryswap.Tpo" -c -o tryswap.o
/home/gchernis/tryswap/src/tryswap.cpp; then mv -f ".deps/tryswap.Tpo"
".deps/tryswap.Po"; else rm -f ".deps/tryswap.Tpo"; exit 1; fi
/home/gchernis/tryswap/src/tryswap.cpp: In function ‘void
ConvertFloatSSE(void*, void*, int)’:
/home/gchernis/tryswap/src/tryswap.cpp:189: error: unable to find a register to
spill in class ‘GENERAL_REGS’
/home/gchernis/tryswap/src/tryswap.cpp:189: error: this is the insn:
(insn 90 89 91 2 (parallel [
(set (subreg:DI (reg:V16QI 21 xmm0 [102]) 0)
(ashift:DI (reg:DI 1 dx [90])
(const_int 8 [0x8])))
(clobber (reg:CC 17 flags))
]) 394 {*ashldi3_1_rex64} (insn_list:REG_DEP_TRUE 66 (nil))
(expr_list:REG_UNUSED (reg:CC 17 flags)
(expr_list:REG_UNUSED (reg:CC 17 flags)
(expr_list:REG_DEAD (reg:DI 1 dx [90])
(nil)))))
/home/gchernis/tryswap/src/tryswap.cpp:189: confused by earlier errors, bailing
out
gmake[2]: *** [tryswap.o] Error 1
gmake[1]: *** [all-recursive] Error 1
gmake: *** [all] Error 2
*** Exited with status: 2 ***


-- 
           Summary: SSE byte-by-byte load instruction fails to compile
           Product: gcc
           Version: 4.0.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gchernis11 at msn dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26445