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author | Richard Henderson <rth@twiddle.net> | 2013-03-04 22:06:21 -0800 |
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committer | Aurelien Jarno <aurelien@aurel32.net> | 2013-04-27 02:16:43 +0200 |
commit | a9a86ae95d24c587285856405dffc9cacdf2b683 (patch) | |
tree | 915a4fb1604f2cc7a569e109f3c27cf5f67a7869 | |
parent | 19b62bf4148d834c709c464f6fb1c6b72f906250 (diff) | |
download | hqemu-a9a86ae95d24c587285856405dffc9cacdf2b683.zip hqemu-a9a86ae95d24c587285856405dffc9cacdf2b683.tar.gz |
tcg-arm: Handle negated constant arguments to and/sub
This greatly improves code generation for addition of small
negative constants.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
-rw-r--r-- | tcg/arm/tcg-target.c | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index 886252f..de8465b 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -147,6 +147,7 @@ static void patch_reloc(uint8_t *code_ptr, int type, #define TCG_CT_CONST_ARM 0x100 #define TCG_CT_CONST_INV 0x200 +#define TCG_CT_CONST_NEG 0x400 /* parse target specific constraints */ static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str) @@ -161,6 +162,9 @@ static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str) case 'K': ct->ct |= TCG_CT_CONST_INV; break; + case 'N': /* The gcc constraint letter is L, already used here. */ + ct->ct |= TCG_CT_CONST_NEG; + break; case 'r': ct->ct |= TCG_CT_REG; @@ -291,6 +295,8 @@ static inline int tcg_target_const_match(tcg_target_long val, return 1; } else if ((ct & TCG_CT_CONST_INV) && check_fit_imm(~val)) { return 1; + } else if ((ct & TCG_CT_CONST_NEG) && check_fit_imm(-val)) { + return 1; } else { return 0; } @@ -512,6 +518,27 @@ static void tcg_out_dat_rIK(TCGContext *s, int cond, int opc, int opinv, } } +static void tcg_out_dat_rIN(TCGContext *s, int cond, int opc, int opneg, + TCGArg dst, TCGArg lhs, TCGArg rhs, + bool rhs_is_const) +{ + /* Emit either the reg,imm or reg,reg form of a data-processing insn. + * rhs must satisfy the "rIN" constraint. + */ + if (rhs_is_const) { + int rot = encode_imm(rhs); + if (rot < 0) { + rhs = -rhs; + rot = encode_imm(rhs); + assert(rot >= 0); + opc = opneg; + } + tcg_out_dat_imm(s, cond, opc, dst, lhs, rotl(rhs, rot) | (rot << 7)); + } else { + tcg_out_dat_reg(s, cond, opc, dst, lhs, rhs, SHIFT_IMM_LSL(0)); + } +} + static inline void tcg_out_mul32(TCGContext *s, int cond, int rd, int rs, int rm) { @@ -1594,11 +1621,13 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, ARITH_MOV, args[0], 0, args[3], const_args[3]); break; case INDEX_op_add_i32: - c = ARITH_ADD; - goto gen_arith; + tcg_out_dat_rIN(s, COND_AL, ARITH_ADD, ARITH_SUB, + args[0], args[1], args[2], const_args[2]); + break; case INDEX_op_sub_i32: - c = ARITH_SUB; - goto gen_arith; + tcg_out_dat_rIN(s, COND_AL, ARITH_SUB, ARITH_ADD, + args[0], args[1], args[2], const_args[2]); + break; case INDEX_op_and_i32: tcg_out_dat_rIK(s, COND_AL, ARITH_AND, ARITH_BIC, args[0], args[1], args[2], const_args[2]); @@ -1789,8 +1818,8 @@ static const TCGTargetOpDef arm_op_defs[] = { { INDEX_op_st_i32, { "r", "r" } }, /* TODO: "r", "r", "ri" */ - { INDEX_op_add_i32, { "r", "r", "rI" } }, - { INDEX_op_sub_i32, { "r", "r", "rI" } }, + { INDEX_op_add_i32, { "r", "r", "rIN" } }, + { INDEX_op_sub_i32, { "r", "r", "rIN" } }, { INDEX_op_mul_i32, { "r", "r", "r" } }, { INDEX_op_mulu2_i32, { "r", "r", "r", "r" } }, { INDEX_op_muls2_i32, { "r", "r", "r", "r" } }, |