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tcg-aarch64: Special case small constants in tcg_out_movi

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Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2013-09-11 13:44:17 -07:00 committed by Richard Henderson
parent 4ec4f0bd56
commit d8918df577
1 changed files with 10 additions and 0 deletions
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10
tcg/aarch64/tcg-target.c
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@ -578,6 +578,16 @@ static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
type = TCG_TYPE_I32; type = TCG_TYPE_I32;
} }
/* Speed things up by handling the common case of small positive
and negative values specially. */
if ((value & ~0xffffull) == 0) {
tcg_out_insn(s, 3405, MOVZ, type, rd, value, 0);
return;
} else if ((ivalue & ~0xffffull) == 0) {
tcg_out_insn(s, 3405, MOVN, type, rd, ivalue, 0);
return;
}
/* Check for bitfield immediates. For the benefit of 32-bit quantities, /* Check for bitfield immediates. For the benefit of 32-bit quantities,
use the sign-extended value. That lets us match rotated values such use the sign-extended value. That lets us match rotated values such
as 0xff0000ff with the same 64-bit logic matching 0xffffffffff0000ff. */ as 0xff0000ff with the same 64-bit logic matching 0xffffffffff0000ff. */