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tcg-i386: Use lea for three-operand add.

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The result is shorter than the mov+add that TCG would
otherwise generate for us.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Richard Henderson 2010-05-21 08:30:34 -07:00 committed by Aurelien Jarno
parent 34a6d0b7fc
commit 5d1e4e85ce
1 changed files with 20 additions and 3 deletions
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23
tcg/i386/tcg-target.c
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@ -1165,6 +1165,25 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
case INDEX_op_st_i32:
tcg_out_st(s, TCG_TYPE_I32, args[0], args[1], args[2]);
break;
case INDEX_op_add_i32:
/* For 3-operand addition, use LEA. */
if (args[0] != args[1]) {
TCGArg a0 = args[0], a1 = args[1], a2 = args[2], c3 = 0;
if (const_args[2]) {
c3 = a2, a2 = -1;
} else if (a0 == a2) {
/* Watch out for dest = src + dest, since we've removed
the matching constraint on the add. */
tgen_arithr(s, ARITH_ADD, a0, a1);
break;
}
tcg_out_modrm_sib_offset(s, OPC_LEA, a0, a1, a2, 0, c3);
break;
}
c = ARITH_ADD;
goto gen_arith;
case INDEX_op_sub_i32:
c = ARITH_SUB;
goto gen_arith;
@ -1177,8 +1196,6 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
case INDEX_op_xor_i32:
c = ARITH_XOR;
goto gen_arith;
case INDEX_op_add_i32:
c = ARITH_ADD;
gen_arith:
if (const_args[2]) {
tgen_arithi(s, c, args[0], args[2], 0);
@ -1353,7 +1370,7 @@ static const TCGTargetOpDef x86_op_defs[] = {
{ INDEX_op_st16_i32, { "r", "r" } },
{ INDEX_op_st_i32, { "r", "r" } },
{ INDEX_op_add_i32, { "r", "0", "ri" } },
{ INDEX_op_add_i32, { "r", "r", "ri" } },
{ INDEX_op_sub_i32, { "r", "0", "ri" } },
{ INDEX_op_mul_i32, { "r", "0", "ri" } },
{ INDEX_op_mulu2_i32, { "a", "d", "a", "r" } },