From 829e1376d94009a7ccacc0535bffcc679f7bb507 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 25 Jul 2017 11:53:50 -0700 Subject: [PATCH] tcg/s390: Introduce TCG_REG_TB Signed-off-by: Richard Henderson --- tcg/s390/tcg-target.h | 2 +- tcg/s390/tcg-target.inc.c | 71 +++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 61 insertions(+), 12 deletions(-) diff --git a/tcg/s390/tcg-target.h b/tcg/s390/tcg-target.h index 52010c30cb..9c9c8cd464 100644 --- a/tcg/s390/tcg-target.h +++ b/tcg/s390/tcg-target.h @@ -95,7 +95,7 @@ extern uint64_t s390_facilities; #define TCG_TARGET_HAS_extrl_i64_i32 0 #define TCG_TARGET_HAS_extrh_i64_i32 0 #define TCG_TARGET_HAS_goto_ptr 1 -#define TCG_TARGET_HAS_direct_jump 1 +#define TCG_TARGET_HAS_direct_jump (s390_facilities & FACILITY_GEN_INST_EXT) #define TCG_TARGET_HAS_div2_i64 1 #define TCG_TARGET_HAS_rot_i64 1 diff --git a/tcg/s390/tcg-target.inc.c b/tcg/s390/tcg-target.inc.c index ee0dff995a..e007586315 100644 --- a/tcg/s390/tcg-target.inc.c +++ b/tcg/s390/tcg-target.inc.c @@ -51,6 +51,12 @@ /* A scratch register that may be be used throughout the backend. */ #define TCG_TMP0 TCG_REG_R1 +/* A scratch register that holds a pointer to the beginning of the TB. + We don't need this when we have pc-relative loads with the general + instructions extension facility. */ +#define TCG_REG_TB TCG_REG_R12 +#define USE_REG_TB (!(s390_facilities & FACILITY_GEN_INST_EXT)) + #ifndef CONFIG_SOFTMMU #define TCG_GUEST_BASE_REG TCG_REG_R13 #endif @@ -556,8 +562,8 @@ static void tcg_out_mov(TCGContext *s, TCGType type, TCGReg dst, TCGReg src) } /* load a register with an immediate value */ -static void tcg_out_movi(TCGContext *s, TCGType type, - TCGReg ret, tcg_target_long sval) +static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret, + tcg_target_long sval, bool in_prologue) { static const S390Opcode lli_insns[4] = { RI_LLILL, RI_LLILH, RI_LLIHL, RI_LLIHH @@ -601,13 +607,22 @@ static void tcg_out_movi(TCGContext *s, TCGType type, } } - /* Try for PC-relative address load. */ + /* Try for PC-relative address load. For odd addresses, + attempt to use an offset from the start of the TB. */ if ((sval & 1) == 0) { ptrdiff_t off = tcg_pcrel_diff(s, (void *)sval) >> 1; if (off == (int32_t)off) { tcg_out_insn(s, RIL, LARL, ret, off); return; } + } else if (USE_REG_TB && !in_prologue) { + ptrdiff_t off = sval - (uintptr_t)s->code_gen_ptr; + if (off == sextract64(off, 0, 20)) { + /* This is certain to be an address within TB, and therefore + OFF will be negative; don't try RX_LA. */ + tcg_out_insn(s, RXY, LAY, ret, TCG_REG_TB, TCG_REG_NONE, off); + return; + } } /* If extended immediates are not present, then we may have to issue @@ -663,6 +678,11 @@ static void tcg_out_movi(TCGContext *s, TCGType type, } } +static void tcg_out_movi(TCGContext *s, TCGType type, + TCGReg ret, tcg_target_long sval) +{ + tcg_out_movi_int(s, type, ret, sval, false); +} /* Emit a load/store type instruction. Inputs are: DATA: The register to be loaded or stored. @@ -739,6 +759,13 @@ static void tcg_out_ld_abs(TCGContext *s, TCGType type, TCGReg dest, void *abs) return; } } + if (USE_REG_TB) { + ptrdiff_t disp = abs - (void *)s->code_gen_ptr; + if (disp == sextract64(disp, 0, 20)) { + tcg_out_ld(s, type, dest, TCG_REG_TB, disp); + return; + } + } tcg_out_movi(s, TCG_TYPE_PTR, dest, addr & ~0xffff); tcg_out_ld(s, type, dest, dest, addr & 0xffff); @@ -1690,6 +1717,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, break; case INDEX_op_goto_tb: + a0 = args[0]; if (s->tb_jmp_insn_offset) { /* branch displacement must be aligned for atomic patching; * see if we need to add extra nop before branch @@ -1697,21 +1725,34 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, if (!QEMU_PTR_IS_ALIGNED(s->code_ptr + 1, 4)) { tcg_out16(s, NOP); } + tcg_debug_assert(!USE_REG_TB); tcg_out16(s, RIL_BRCL | (S390_CC_ALWAYS << 4)); - s->tb_jmp_insn_offset[args[0]] = tcg_current_code_size(s); + s->tb_jmp_insn_offset[a0] = tcg_current_code_size(s); s->code_ptr += 2; } else { - /* load address stored at s->tb_jmp_target_addr + args[0] */ - tcg_out_ld_abs(s, TCG_TYPE_PTR, TCG_TMP0, - s->tb_jmp_target_addr + args[0]); + /* load address stored at s->tb_jmp_target_addr + a0 */ + tcg_out_ld_abs(s, TCG_TYPE_PTR, TCG_REG_TB, + s->tb_jmp_target_addr + a0); /* and go there */ - tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_TMP0); + tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_TB); + } + s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); + + /* For the unlinked path of goto_tb, we need to reset + TCG_REG_TB to the beginning of this TB. */ + if (USE_REG_TB) { + int ofs = -tcg_current_code_size(s); + assert(ofs == (int16_t)ofs); + tcg_out_insn(s, RI, AGHI, TCG_REG_TB, ofs); } - s->tb_jmp_reset_offset[args[0]] = tcg_current_code_size(s); break; case INDEX_op_goto_ptr: - tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, args[0]); + a0 = args[0]; + if (USE_REG_TB) { + tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_TB, a0); + } + tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, a0); break; OP_32_64(ld8u): @@ -2476,6 +2517,9 @@ static void tcg_target_init(TCGContext *s) /* XXX many insns can't be used with R0, so we better avoid it for now */ tcg_regset_set_reg(s->reserved_regs, TCG_REG_R0); tcg_regset_set_reg(s->reserved_regs, TCG_REG_CALL_STACK); + if (USE_REG_TB) { + tcg_regset_set_reg(s->reserved_regs, TCG_REG_TB); + } } #define FRAME_SIZE ((int)(TCG_TARGET_CALL_STACK_OFFSET \ @@ -2496,12 +2540,17 @@ static void tcg_target_qemu_prologue(TCGContext *s) #ifndef CONFIG_SOFTMMU if (guest_base >= 0x80000) { - tcg_out_movi(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, guest_base); + tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, guest_base, true); tcg_regset_set_reg(s->reserved_regs, TCG_GUEST_BASE_REG); } #endif tcg_out_mov(s, TCG_TYPE_PTR, TCG_AREG0, tcg_target_call_iarg_regs[0]); + if (USE_REG_TB) { + tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_TB, + tcg_target_call_iarg_regs[1]); + } + /* br %r3 (go to TB) */ tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, tcg_target_call_iarg_regs[1]); -- 2.11.0