fsgnj.s

Single-precision sign inject

This instruction is defined by:

Encoding

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Synopsis

Writes fd with sign bit of fs2 and the exponent and mantissa of fs1.

Sign-injection instructions do not set floating-point exception flags, nor do they canonicalize NaNs.

Access

M

HS

U

VS

VU

Always

Always

Always

Always

Always

Decode Variables

Bits<5> fs2 = $encoding[24:20];
Bits<5> fs1 = $encoding[19:15];
Bits<5> fd = $encoding[11:7];

Execution

  • Pruned, XLEN == 64

  • Original

%%LINK%func;check_f_ok;check_f_ok%%($encoding);
Bits<32> sp_value = {f[fs2][31], f[fs1][30:0]};
f[fd] = %%LINK%func;nan_box;nan_box%%<32, 64>(sp_value);
%%LINK%func;mark_f_state_dirty;mark_f_state_dirty%%();
%%LINK%func;check_f_ok;check_f_ok%%($encoding);
Bits<32> sp_value = {f[fs2][31], f[fs1][30:0]};
if (%%LINK%func;implemented?;implemented?%%(ExtensionName::D)) {
  f[fd] = %%LINK%func;nan_box;nan_box%%<32, 64>(sp_value);
} else {
  f[fd] = sp_value;
}
%%LINK%func;mark_f_state_dirty;mark_f_state_dirty%%();

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction