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tcg/x86_64: Special-case all 32-bit AND operands.

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This avoids an unnecessary REX.W prefix when dealing with AND
operands that fit into a 32-bit quantity.  The most common change
actually seen is movz[wb]q -> movz[wb]l.

Similarly, avoid REXW in ext{8,16}u_i64 tcg opcodes.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Richard Henderson 2010-01-05 16:03:00 -08:00 committed by Aurelien Jarno
parent 0a4e7cd237
commit 5716990376
1 changed files with 8 additions and 18 deletions
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26
tcg/x86_64/tcg-target.c
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@ -426,24 +426,18 @@ static inline void tgen_arithi64(TCGContext *s, int c, int r0, int64_t val)
} else if ((c == ARITH_ADD && val == -1) || (c == ARITH_SUB && val == 1)) {
/* dec */
tcg_out_modrm(s, 0xff | P_REXW, 1, r0);
} else if (val == (int8_t)val) {
tcg_out_modrm(s, 0x83 | P_REXW, c, r0);
tcg_out8(s, val);
} else if (c == ARITH_AND && val == 0xffu) {
/* movzbl */
tcg_out_modrm(s, 0xb6 | P_EXT | P_REXW, r0, r0);
} else if (c == ARITH_AND && val == 0xffffu) {
/* movzwl */
tcg_out_modrm(s, 0xb7 | P_EXT | P_REXW, r0, r0);
} else if (c == ARITH_AND && val == 0xffffffffu) {
/* 32-bit mov zero extends */
tcg_out_modrm(s, 0x8b, r0, r0);
} else if (c == ARITH_AND && val == (uint32_t)val) {
/* AND with no high bits set can use a 32-bit operation. */
tgen_arithi32(s, c, r0, (uint32_t)val);
} else if (val == (int8_t)val) {
tcg_out_modrm(s, 0x83 | P_REXW, c, r0);
tcg_out8(s, val);
} else if (val == (int32_t)val) {
tcg_out_modrm(s, 0x81 | P_REXW, c, r0);
tcg_out32(s, val);
} else if (c == ARITH_AND && val == (uint32_t)val) {
tcg_out_modrm(s, 0x81, c, r0);
tcg_out32(s, val);
} else {
tcg_abort();
}
@ -1182,16 +1176,12 @@ static inline void tcg_out_op(TCGContext *s, int opc, const TCGArg *args,
tcg_out_modrm(s, 0x63 | P_REXW, args[0], args[1]);
break;
case INDEX_op_ext8u_i32:
case INDEX_op_ext8u_i64:
tcg_out_modrm(s, 0xb6 | P_EXT | P_REXB, args[0], args[1]);
break;
case INDEX_op_ext16u_i32:
tcg_out_modrm(s, 0xb7 | P_EXT, args[0], args[1]);
break;
case INDEX_op_ext8u_i64:
tcg_out_modrm(s, 0xb6 | P_EXT | P_REXW, args[0], args[1]);
break;
case INDEX_op_ext16u_i64:
tcg_out_modrm(s, 0xb7 | P_EXT | P_REXW, args[0], args[1]);
tcg_out_modrm(s, 0xb7 | P_EXT, args[0], args[1]);
break;
case INDEX_op_ext32u_i64:
tcg_out_modrm(s, 0x8b, args[0], args[1]);