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tcg/arm: add bswap ops

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Add an bswap16 and bswap32 ops, either using the rev and rev16
instructions on ARMv6+ or shifts and logical operations on previous
ARM versions. In both cases the result use less instructions than
the pure TCG version.

These ops are also needed by the qemu_ld/st functions.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2010-04-09 20:52:48 +02:00
parent 9517094f72
commit 244b1e81f6
2 changed files with 44 additions and 2 deletions
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42
tcg/arm/tcg-target.c
View File

@ -527,6 +527,38 @@ static inline void tcg_out_ext16u(TCGContext *s, int cond,
}
}
static inline void tcg_out_bswap16(TCGContext *s, int cond, int rd, int rn)
{
if (use_armv6_instructions) {
/* rev16 */
tcg_out32(s, 0x06bf0fb0 | (cond << 28) | (rd << 12) | rn);
} else {
tcg_out_dat_reg(s, cond, ARITH_MOV,
TCG_REG_R8, 0, rn, SHIFT_IMM_LSL(24));
tcg_out_dat_reg(s, cond, ARITH_MOV,
TCG_REG_R8, 0, TCG_REG_R8, SHIFT_IMM_LSR(16));
tcg_out_dat_reg(s, cond, ARITH_ORR,
rd, TCG_REG_R8, rn, SHIFT_IMM_LSR(8));
}
}
static inline void tcg_out_bswap32(TCGContext *s, int cond, int rd, int rn)
{
if (use_armv6_instructions) {
/* rev */
tcg_out32(s, 0x06bf0f30 | (cond << 28) | (rd << 12) | rn);
} else {
tcg_out_dat_reg(s, cond, ARITH_EOR,
TCG_REG_R8, rn, rn, SHIFT_IMM_ROR(16));
tcg_out_dat_imm(s, cond, ARITH_BIC,
TCG_REG_R8, TCG_REG_R8, 0xff | 0x800);
tcg_out_dat_reg(s, cond, ARITH_MOV,
rd, 0, rn, SHIFT_IMM_ROR(8));
tcg_out_dat_reg(s, cond, ARITH_EOR,
rd, rd, TCG_REG_R8, SHIFT_IMM_LSR(8));
}
}
static inline void tcg_out_ld32_12(TCGContext *s, int cond,
int rd, int rn, tcg_target_long im)
{
@ -1544,6 +1576,13 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
tcg_out_qemu_st(s, COND_AL, args, 3);
break;
case INDEX_op_bswap16_i32:
tcg_out_bswap16(s, COND_AL, args[0], args[1]);
break;
case INDEX_op_bswap32_i32:
tcg_out_bswap32(s, COND_AL, args[0], args[1]);
break;
case INDEX_op_ext8s_i32:
tcg_out_ext8s(s, COND_AL, args[0], args[1]);
break;
@ -1631,6 +1670,9 @@ static const TCGTargetOpDef arm_op_defs[] = {
{ INDEX_op_qemu_st64, { "x", "D", "x", "X" } },
#endif
{ INDEX_op_bswap16_i32, { "r", "r" } },
{ INDEX_op_bswap32_i32, { "r", "r" } },
{ INDEX_op_ext8s_i32, { "r", "r" } },
{ INDEX_op_ext16s_i32, { "r", "r" } },
{ INDEX_op_ext16u_i32, { "r", "r" } },

4
tcg/arm/tcg-target.h
View File

@ -62,8 +62,8 @@ enum {
#define TCG_TARGET_HAS_ext16s_i32
#undef TCG_TARGET_HAS_ext8u_i32 /* and r0, r1, #0xff */
#define TCG_TARGET_HAS_ext16u_i32
// #define TCG_TARGET_HAS_bswap16_i32
// #define TCG_TARGET_HAS_bswap32_i32
#define TCG_TARGET_HAS_bswap16_i32
#define TCG_TARGET_HAS_bswap32_i32
#define TCG_TARGET_HAS_not_i32
#define TCG_TARGET_HAS_neg_i32
#define TCG_TARGET_HAS_rot_i32