[Bug rtl-optimization/19680] sub-optimial register allocation with sse

[tbptbp at gmail dot com]

------- Additional Comments From tbptbp at gmail dot com  2005-01-31 14:14 -------
Yes, and i'm not asking for a GPR->SSE transfer. What i'm asking is why gcc
feels the urge to copy that memory reference to the stack before fooling around
with it.

The full sequence is:
  401298:       8b 42 28                mov    0x28(%edx),%eax
  40129b:       89 44 24 1c             mov    %eax,0x1c(%esp)
  40129f:       66 0f 6e 64 24 1c       movd   0x1c(%esp),%xmm4
  4012a5:       66 0f 70 cc 00          pshufd $0x0,%xmm4,%xmm1

whereas ICC does:
  40241d:       66 0f 6e 44 ca 28       movd   0x28(%edx,%ecx,8),%xmm0
  40242c:       66 0f 70 c0 00          pshufd $0x0,%xmm0,%xmm0

I've opened http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19714 for this.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19680