From e029f29385d0f9116c717d2e7a9c55d4bac8fe8a Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 14 Aug 2013 11:27:03 -0700 Subject: tcg-aarch64: Handle constant operands to and, or, xor Handle a simplified set of logical immediates for the moment. The way gcc and binutils do it, with 52k worth of tables, and a binary search depth of log2(5334) = 13, seems slow for the most common cases. Signed-off-by: Richard Henderson Reviewed-by: Claudio Fontana Tested-by: Claudio Fontana --- tcg/aarch64/tcg-target.c | 156 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 107 insertions(+), 49 deletions(-) diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c index 6816debe82..9a34a15266 100644 --- a/tcg/aarch64/tcg-target.c +++ b/tcg/aarch64/tcg-target.c @@ -112,6 +112,7 @@ static inline void patch_reloc(uint8_t *code_ptr, int type, #define TCG_CT_CONST_IS32 0x100 #define TCG_CT_CONST_AIMM 0x200 +#define TCG_CT_CONST_LIMM 0x400 /* parse target specific constraints */ static int target_parse_constraint(TCGArgConstraint *ct, @@ -142,6 +143,9 @@ static int target_parse_constraint(TCGArgConstraint *ct, case 'A': /* Valid for arithmetic immediate (positive or negative). */ ct->ct |= TCG_CT_CONST_AIMM; break; + case 'L': /* Valid for logical immediate. */ + ct->ct |= TCG_CT_CONST_LIMM; + break; default: return -1; } @@ -156,6 +160,26 @@ static inline bool is_aimm(uint64_t val) return (val & ~0xfff) == 0 || (val & ~0xfff000) == 0; } +static inline bool is_limm(uint64_t val) +{ + /* Taking a simplified view of the logical immediates for now, ignoring + the replication that can happen across the field. Match bit patterns + of the forms + 0....01....1 + 0..01..10..0 + and their inverses. */ + + /* Make things easier below, by testing the form with msb clear. */ + if ((int64_t)val < 0) { + val = ~val; + } + if (val == 0) { + return false; + } + val += val & -val; + return (val & (val - 1)) == 0; +} + static int tcg_target_const_match(tcg_target_long val, const TCGArgConstraint *arg_ct) { @@ -170,6 +194,9 @@ static int tcg_target_const_match(tcg_target_long val, if ((ct & TCG_CT_CONST_AIMM) && (is_aimm(val) || is_aimm(-val))) { return 1; } + if ((ct & TCG_CT_CONST_LIMM) && is_limm(val)) { + return 1; + } return 0; } @@ -235,6 +262,11 @@ typedef enum { I3401_SUBI = 0x51000000, I3401_SUBSI = 0x71000000, + /* Logical immediate instructions. */ + I3404_ANDI = 0x12000000, + I3404_ORRI = 0x32000000, + I3404_EORI = 0x52000000, + /* Add/subtract shifted register instructions (without a shift). */ I3502_ADD = 0x0b000000, I3502_ADDS = 0x2b000000, @@ -351,6 +383,18 @@ static void tcg_out_insn_3401(TCGContext *s, AArch64Insn insn, TCGType ext, tcg_out32(s, insn | ext << 31 | aimm << 10 | rn << 5 | rd); } +/* This function can be used for both 3.4.2 (Bitfield) and 3.4.4 + (Logical immediate). Both insn groups have N, IMMR and IMMS fields + that feed the DecodeBitMasks pseudo function. */ +static void tcg_out_insn_3402(TCGContext *s, AArch64Insn insn, TCGType ext, + TCGReg rd, TCGReg rn, int n, int immr, int imms) +{ + tcg_out32(s, insn | ext << 31 | n << 22 | immr << 16 | imms << 10 + | rn << 5 | rd); +} + +#define tcg_out_insn_3404 tcg_out_insn_3402 + /* This function is for both 3.5.2 (Add/Subtract shifted register), for the rare occasion when we actually want to supply a shift amount. */ static inline void tcg_out_insn_3502S(TCGContext *s, AArch64Insn insn, @@ -665,40 +709,6 @@ static inline void tcg_out_call(TCGContext *s, intptr_t target) } } -/* encode a logical immediate, mapping user parameter - M=set bits pattern length to S=M-1 */ -static inline unsigned int -aarch64_limm(unsigned int m, unsigned int r) -{ - assert(m > 0); - return r << 16 | (m - 1) << 10; -} - -/* test a register against an immediate bit pattern made of - M set bits rotated right by R. - Examples: - to test a 32/64 reg against 0x00000007, pass M = 3, R = 0. - to test a 32/64 reg against 0x000000ff, pass M = 8, R = 0. - to test a 32bit reg against 0xff000000, pass M = 8, R = 8. - to test a 32bit reg against 0xff0000ff, pass M = 16, R = 8. - */ -static inline void tcg_out_tst(TCGContext *s, TCGType ext, TCGReg rn, - unsigned int m, unsigned int r) -{ - /* using TST alias of ANDS XZR, Xn,#bimm64 0x7200001f */ - unsigned int base = ext ? 0xf240001f : 0x7200001f; - tcg_out32(s, base | aarch64_limm(m, r) | rn << 5); -} - -/* and a register with a bit pattern, similarly to TST, no flags change */ -static inline void tcg_out_andi(TCGContext *s, TCGType ext, TCGReg rd, - TCGReg rn, unsigned int m, unsigned int r) -{ - /* using AND 0x12000000 */ - unsigned int base = ext ? 0x92400000 : 0x12000000; - tcg_out32(s, base | aarch64_limm(m, r) | rn << 5 | rd); -} - static inline void tcg_out_ret(TCGContext *s) { /* emit RET { LR } */ @@ -788,6 +798,37 @@ static void tcg_out_addsubi(TCGContext *s, int ext, TCGReg rd, } } +/* This function is used for the Logical (immediate) instruction group. + The value of LIMM must satisfy IS_LIMM. See the comment above about + only supporting simplified logical immediates. */ +static void tcg_out_logicali(TCGContext *s, AArch64Insn insn, TCGType ext, + TCGReg rd, TCGReg rn, uint64_t limm) +{ + unsigned h, l, r, c; + + assert(is_limm(limm)); + + h = clz64(limm); + l = ctz64(limm); + if (l == 0) { + r = 0; /* form 0....01....1 */ + c = ctz64(~limm) - 1; + if (h == 0) { + r = clz64(~limm); /* form 1..10..01..1 */ + c += r; + } + } else { + r = 64 - l; /* form 1....10....0 or 0..01..10..0 */ + c = r - h - 1; + } + if (ext == TCG_TYPE_I32) { + r &= 31; + c &= 31; + } + + tcg_out_insn_3404(s, insn, ext, rd, rn, ext, r, c); +} + #ifdef CONFIG_SOFTMMU /* helper signature: helper_ret_ld_mmu(CPUState *env, target_ulong addr, * int mmu_idx, uintptr_t ra) @@ -879,9 +920,8 @@ static void tcg_out_tlb_read(TCGContext *s, TCGReg addr_reg, /* Store the page mask part of the address and the low s_bits into X3. Later this allows checking for equality and alignment at the same time. X3 = addr_reg & (PAGE_MASK | ((1 << s_bits) - 1)) */ - tcg_out_andi(s, (TARGET_LONG_BITS == 64), TCG_REG_X3, addr_reg, - (TARGET_LONG_BITS - TARGET_PAGE_BITS) + s_bits, - (TARGET_LONG_BITS - TARGET_PAGE_BITS)); + tcg_out_logicali(s, I3404_ANDI, TARGET_LONG_BITS == 64, TCG_REG_X3, + addr_reg, TARGET_PAGE_MASK | ((1 << s_bits) - 1)); /* Add any "high bits" from the tlb offset to the env address into X2, to take advantage of the LSL12 form of the ADDI instruction. X2 = env + (tlb_offset & 0xfff000) */ @@ -1186,19 +1226,37 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, } break; - case INDEX_op_and_i64: case INDEX_op_and_i32: - tcg_out_insn(s, 3510, AND, ext, a0, a1, a2); + a2 = (int32_t)a2; + /* FALLTHRU */ + case INDEX_op_and_i64: + if (c2) { + tcg_out_logicali(s, I3404_ANDI, ext, a0, a1, a2); + } else { + tcg_out_insn(s, 3510, AND, ext, a0, a1, a2); + } break; - case INDEX_op_or_i64: case INDEX_op_or_i32: - tcg_out_insn(s, 3510, ORR, ext, a0, a1, a2); + a2 = (int32_t)a2; + /* FALLTHRU */ + case INDEX_op_or_i64: + if (c2) { + tcg_out_logicali(s, I3404_ORRI, ext, a0, a1, a2); + } else { + tcg_out_insn(s, 3510, ORR, ext, a0, a1, a2); + } break; - case INDEX_op_xor_i64: case INDEX_op_xor_i32: - tcg_out_insn(s, 3510, EOR, ext, a0, a1, a2); + a2 = (int32_t)a2; + /* FALLTHRU */ + case INDEX_op_xor_i64: + if (c2) { + tcg_out_logicali(s, I3404_EORI, ext, a0, a1, a2); + } else { + tcg_out_insn(s, 3510, EOR, ext, a0, a1, a2); + } break; case INDEX_op_mul_i64: @@ -1391,12 +1449,12 @@ static const TCGTargetOpDef aarch64_op_defs[] = { { INDEX_op_sub_i64, { "r", "r", "rA" } }, { INDEX_op_mul_i32, { "r", "r", "r" } }, { INDEX_op_mul_i64, { "r", "r", "r" } }, - { INDEX_op_and_i32, { "r", "r", "r" } }, - { INDEX_op_and_i64, { "r", "r", "r" } }, - { INDEX_op_or_i32, { "r", "r", "r" } }, - { INDEX_op_or_i64, { "r", "r", "r" } }, - { INDEX_op_xor_i32, { "r", "r", "r" } }, - { INDEX_op_xor_i64, { "r", "r", "r" } }, + { INDEX_op_and_i32, { "r", "r", "rwL" } }, + { INDEX_op_and_i64, { "r", "r", "rL" } }, + { INDEX_op_or_i32, { "r", "r", "rwL" } }, + { INDEX_op_or_i64, { "r", "r", "rL" } }, + { INDEX_op_xor_i32, { "r", "r", "rwL" } }, + { INDEX_op_xor_i64, { "r", "r", "rL" } }, { INDEX_op_shl_i32, { "r", "r", "ri" } }, { INDEX_op_shr_i32, { "r", "r", "ri" } }, -- cgit v1.2.1