tcg-mips: Add bswap32u and bswap64

Without the mips32r2 instructions to perform swapping, bswap is quite large,
dominating the size of each reverse-endian qemu_ld/qemu_st operation.

Create two subroutines in the prologue block. The subroutines require extra
reserved registers (TCG_TMP[2, 3]). Using these within qemu_ld means that
we need not place additional restrictions on the qemu_ld outputs.

Backports commit 7f54eaa3b78d71cb57e45a719980f9b5ff06d21c from qemu
This commit is contained in:
Jin Guojie 2018-03-01 12:47:41 -05:00 committed by Lioncash
parent 397db1b046
commit 00ccf9cec7
No known key found for this signature in database
GPG key ID: 4E3C3CC1031BA9C7

View file

@ -125,6 +125,8 @@ static const TCGReg tcg_target_call_oarg_regs[2] = {
static tcg_insn_unit *tb_ret_addr;
static tcg_insn_unit *bswap32_addr;
static tcg_insn_unit *bswap32u_addr;
static tcg_insn_unit *bswap64_addr;
static inline uint32_t reloc_pc16_val(tcg_insn_unit *pc, tcg_insn_unit *target)
{
@ -627,7 +629,10 @@ static void tcg_out_bswap32u(TCGContext *s, TCGReg ret, TCGReg arg)
tcg_out_opc_reg(s, OPC_DSHD, ret, 0, ret);
tcg_out_dsrl(s, ret, ret, 32);
} else {
abort();
tcg_out_bswap_subr(s, bswap32u_addr);
/* delay slot -- never omit the insn, like tcg_out_mov might. */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP0, arg, TCG_REG_ZERO);
tcg_out_mov(s, TCG_TYPE_I32, ret, TCG_TMP3);
}
}
@ -637,7 +642,10 @@ static void tcg_out_bswap64(TCGContext *s, TCGReg ret, TCGReg arg)
tcg_out_opc_reg(s, OPC_DSBH, ret, 0, arg);
tcg_out_opc_reg(s, OPC_DSHD, ret, 0, ret);
} else {
abort();
tcg_out_bswap_subr(s, bswap64_addr);
/* delay slot -- never omit the insn, like tcg_out_mov might. */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP0, arg, TCG_REG_ZERO);
tcg_out_mov(s, TCG_TYPE_I32, ret, TCG_TMP3);
}
}
@ -2295,7 +2303,7 @@ static void tcg_target_qemu_prologue(TCGContext *s)
return;
}
/* Bswap subroutine: Input in TCG_TMP0, output in TCG_TMP3;
/* Bswap subroutines: Input in TCG_TMP0, output in TCG_TMP3;
clobbers TCG_TMP1, TCG_TMP2. */
/*
@ -2321,6 +2329,94 @@ static void tcg_target_qemu_prologue(TCGContext *s)
tcg_out_opc_reg(s, OPC_JR, 0, TCG_REG_RA, 0);
/* t3 = dcba -- delay slot */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
if (TCG_TARGET_REG_BITS == 32) {
return;
}
/*
* bswap32u -- unsigned 32-bit swap. a0 = ....abcd.
*/
bswap32u_addr = align_code_ptr(s);
/* t1 = (0000)000d */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP1, TCG_TMP0, 0xff);
/* t3 = 000a */
tcg_out_opc_sa(s, OPC_SRL, TCG_TMP3, TCG_TMP0, 24);
/* t1 = (0000)d000 */
tcg_out_dsll(s, TCG_TMP1, TCG_TMP1, 24);
/* t2 = 00c0 */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP2, TCG_TMP0, 0xff00);
/* t3 = d00a */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
/* t1 = 0abc */
tcg_out_opc_sa(s, OPC_SRL, TCG_TMP1, TCG_TMP0, 8);
/* t2 = 0c00 */
tcg_out_opc_sa(s, OPC_SLL, TCG_TMP2, TCG_TMP2, 8);
/* t1 = 00b0 */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP1, TCG_TMP1, 0xff00);
/* t3 = dc0a */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP2);
tcg_out_opc_reg(s, OPC_JR, 0, TCG_REG_RA, 0);
/* t3 = dcba -- delay slot */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
/*
* bswap64 -- 64-bit swap. a0 = abcdefgh
*/
bswap64_addr = align_code_ptr(s);
/* t3 = h0000000 */
tcg_out_dsll(s, TCG_TMP3, TCG_TMP0, 56);
/* t1 = 0000000a */
tcg_out_dsrl(s, TCG_TMP1, TCG_TMP0, 56);
/* t2 = 000000g0 */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP2, TCG_TMP0, 0xff00);
/* t3 = h000000a */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
/* t1 = 00000abc */
tcg_out_dsrl(s, TCG_TMP1, TCG_TMP0, 40);
/* t2 = 0g000000 */
tcg_out_dsll(s, TCG_TMP2, TCG_TMP2, 40);
/* t1 = 000000b0 */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP1, TCG_TMP1, 0xff00);
/* t3 = hg00000a */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP2);
/* t2 = 0000abcd */
tcg_out_dsrl(s, TCG_TMP2, TCG_TMP0, 32);
/* t3 = hg0000ba */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
/* t1 = 000000c0 */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP1, TCG_TMP2, 0xff00);
/* t2 = 0000000d */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP2, TCG_TMP2, 0x00ff);
/* t1 = 00000c00 */
tcg_out_dsll(s, TCG_TMP1, TCG_TMP1, 8);
/* t2 = 0000d000 */
tcg_out_dsll(s, TCG_TMP2, TCG_TMP2, 24);
/* t3 = hg000cba */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
/* t1 = 00abcdef */
tcg_out_dsrl(s, TCG_TMP1, TCG_TMP0, 16);
/* t3 = hg00dcba */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP2);
/* t2 = 0000000f */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP2, TCG_TMP1, 0x00ff);
/* t1 = 000000e0 */
tcg_out_opc_imm(s, OPC_ANDI, TCG_TMP1, TCG_TMP1, 0xff00);
/* t2 = 00f00000 */
tcg_out_dsll(s, TCG_TMP2, TCG_TMP2, 40);
/* t1 = 000e0000 */
tcg_out_dsll(s, TCG_TMP1, TCG_TMP1, 24);
/* t3 = hgf0dcba */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP2);
tcg_out_opc_reg(s, OPC_JR, 0, TCG_REG_RA, 0);
/* t3 = hgfedcba -- delay slot */
tcg_out_opc_reg(s, OPC_OR, TCG_TMP3, TCG_TMP3, TCG_TMP1);
}
static void tcg_target_init(TCGContext *s)