diff options
author | Richard Henderson <rth@twiddle.net> | 2014-02-27 19:55:30 -0500 |
---|---|---|
committer | Richard Henderson <rth@redhat.com> | 2014-04-16 12:12:59 -0400 |
commit | 3d9e69a238874d70861ac219a5a87320efaf21dd (patch) | |
tree | c76e413db6fb09b1d9e21477f11a4ab55e3418d9 | |
parent | cae1f6f3e60406c4f1a85dc11e0c9eb5a3ce466a (diff) |
tcg-aarch64: Use CBZ and CBNZ
A compare and branch against zero happens at the start of
every single TB.
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
-rw-r--r-- | tcg/aarch64/tcg-target.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c index 5889a988ce..48a246d7a0 100644 --- a/tcg/aarch64/tcg-target.c +++ b/tcg/aarch64/tcg-target.c @@ -270,6 +270,10 @@ enum aarch64_ldst_op_type { /* type of operation */ use the section number of the architecture reference manual in which the instruction group is described. */ typedef enum { + /* Compare and branch (immediate). */ + I3201_CBZ = 0x34000000, + I3201_CBNZ = 0x35000000, + /* Conditional branch (immediate). */ I3202_B_C = 0x54000000, @@ -433,6 +437,12 @@ static inline uint32_t tcg_in32(TCGContext *s) #define tcg_out_insn(S, FMT, OP, ...) \ glue(tcg_out_insn_,FMT)(S, glue(glue(glue(I,FMT),_),OP), ## __VA_ARGS__) +static void tcg_out_insn_3201(TCGContext *s, AArch64Insn insn, TCGType ext, + TCGReg rt, int imm19) +{ + tcg_out32(s, insn | ext << 31 | (imm19 & 0x7ffff) << 5 | rt); +} + static void tcg_out_insn_3202(TCGContext *s, AArch64Insn insn, TCGCond c, int imm19) { @@ -913,8 +923,14 @@ static void tcg_out_brcond(TCGContext *s, TCGMemOp ext, TCGCond c, TCGArg a, { TCGLabel *l = &s->labels[label]; intptr_t offset; + bool need_cmp; - tcg_out_cmp(s, ext, a, b, b_const); + if (b_const && b == 0 && (c == TCG_COND_EQ || c == TCG_COND_NE)) { + need_cmp = false; + } else { + need_cmp = true; + tcg_out_cmp(s, ext, a, b, b_const); + } if (!l->has_value) { tcg_out_reloc(s, s->code_ptr, R_AARCH64_CONDBR19, label, 0); @@ -925,7 +941,13 @@ static void tcg_out_brcond(TCGContext *s, TCGMemOp ext, TCGCond c, TCGArg a, assert(offset >= -0x40000 && offset < 0x40000); } - tcg_out_insn(s, 3202, B_C, c, offset); + if (need_cmp) { + tcg_out_insn(s, 3202, B_C, c, offset); + } else if (c == TCG_COND_EQ) { + tcg_out_insn(s, 3201, CBZ, ext, a, offset); + } else { + tcg_out_insn(s, 3201, CBNZ, ext, a, offset); + } } static inline void tcg_out_rev(TCGContext *s, TCGType ext, |