src/cpu/aarch64/vm/aarch64_ad.m4

rev 11914 : 8221658: aarch64: add necessary predicate for ubfx patterns
Reviewed-by: aph

*** 179,213 ****
  // Bitfield extract with shift & mask
  define(`BFX_INSN',
  `instruct $3$1(iReg$1NoSp dst, iReg$1`'ORL2I($1) src, immI rshift, imm$1_bitmask mask)
  %{
    match(Set dst (And$1 ($2$1 src rshift) mask));
  
    ins_cost(INSN_COST);
    format %{ "$3 $dst, $src, $mask" %}
    ins_encode %{
!     int rshift = $rshift$$constant;
      long mask = $mask$$constant;
!     int width = exact_log2(mask+1);
      __ $3(as_Register($dst$$reg),
              as_Register($src$$reg), rshift, width);
    %}
    ins_pipe(ialu_reg_shift);
  %}')
! BFX_INSN(I,URShift,ubfxw)
! BFX_INSN(L,URShift,ubfx)
  
  // We can use ubfx when extending an And with a mask when we know mask
  // is positive.  We know that because immI_bitmask guarantees it.
  instruct ubfxIConvI2L(iRegLNoSp dst, iRegIorL2I src, immI rshift, immI_bitmask mask)
  %{
    match(Set dst (ConvI2L (AndI (URShiftI src rshift) mask)));
  
    ins_cost(INSN_COST * 2);
    format %{ "ubfx $dst, $src, $mask" %}
    ins_encode %{
!     int rshift = $rshift$$constant;
      long mask = $mask$$constant;
      int width = exact_log2(mask+1);
      __ ubfx(as_Register($dst$$reg),
              as_Register($src$$reg), rshift, width);
    %}
--- 179,217 ----
  // Bitfield extract with shift & mask
  define(`BFX_INSN',
  `instruct $3$1(iReg$1NoSp dst, iReg$1`'ORL2I($1) src, immI rshift, imm$1_bitmask mask)
  %{
    match(Set dst (And$1 ($2$1 src rshift) mask));
+   // Make sure we are not going to exceed what $3 can do.
+   predicate((exact_log2$6(n->in(2)->get_$5() + 1) + (n->in(1)->in(2)->get_int() & $4)) <= ($4 + 1));
  
    ins_cost(INSN_COST);
    format %{ "$3 $dst, $src, $mask" %}
    ins_encode %{
!     int rshift = $rshift$$constant & $4;
      long mask = $mask$$constant;
!     int width = exact_log2$6(mask+1);
      __ $3(as_Register($dst$$reg),
              as_Register($src$$reg), rshift, width);
    %}
    ins_pipe(ialu_reg_shift);
  %}')
! BFX_INSN(I, URShift, ubfxw, 31, int)
! BFX_INSN(L, URShift, ubfx,  63, long, _long)
  
  // We can use ubfx when extending an And with a mask when we know mask
  // is positive.  We know that because immI_bitmask guarantees it.
  instruct ubfxIConvI2L(iRegLNoSp dst, iRegIorL2I src, immI rshift, immI_bitmask mask)
  %{
    match(Set dst (ConvI2L (AndI (URShiftI src rshift) mask)));
+   // Make sure we are not going to exceed what ubfxw can do.
+   predicate((exact_log2(n->in(1)->in(2)->get_int() + 1) + (n->in(1)->in(1)->in(2)->get_int() & 31)) <= (31 + 1));
  
    ins_cost(INSN_COST * 2);
    format %{ "ubfx $dst, $src, $mask" %}
    ins_encode %{
!     int rshift = $rshift$$constant & 31;
      long mask = $mask$$constant;
      int width = exact_log2(mask+1);
      __ ubfx(as_Register($dst$$reg),
              as_Register($src$$reg), rshift, width);
    %}