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| author | Aurelien Jarno <aurelien@aurel32.net> | 2009-09-27 19:57:43 +0200 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2009-09-27 20:00:39 +0200 |
| commit | 17cf428f2e1f6970296b4c0ddcb054e4bc3f2355 (patch) | |
| tree | 28b2e4ca460c386ed433de3f9b49356675007bc2 | |
| parent | b70650cbfea324438f55c2269138dd7f4e7cf086 (diff) | |
| download | qemu-17cf428f2e1f6970296b4c0ddcb054e4bc3f2355.zip qemu-17cf428f2e1f6970296b4c0ddcb054e4bc3f2355.tar.gz qemu-17cf428f2e1f6970296b4c0ddcb054e4bc3f2355.tar.bz2 | |
tcg/i386: generates dec/inc instead of sub/add when possible
We must take care that dec/inc do not compute CF, which is needed by
add2/sub2.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
| -rw-r--r-- | tcg/i386/tcg-target.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c index d318443..b4e3b6f 100644 --- a/tcg/i386/tcg-target.c +++ b/tcg/i386/tcg-target.c @@ -276,9 +276,15 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, int arg, tcg_out_modrm_offset(s, 0x89, arg, arg1, arg2); } -static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val) +static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val, int cf) { - if (val == (int8_t)val) { + if (!cf && ((c == ARITH_ADD && val == 1) || (c == ARITH_SUB && val == -1))) { + /* inc */ + tcg_out_opc(s, 0x40 + r0); + } else if (!cf && ((c == ARITH_ADD && val == -1) || (c == ARITH_SUB && val == 1))) { + /* dec */ + tcg_out_opc(s, 0x48 + r0); + } else if (val == (int8_t)val) { tcg_out_modrm(s, 0x83, c, r0); tcg_out8(s, val); } else if (c == ARITH_AND && val == 0xffu && r0 < 4) { @@ -296,7 +302,7 @@ static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val) static void tcg_out_addi(TCGContext *s, int reg, tcg_target_long val) { if (val != 0) - tgen_arithi(s, ARITH_ADD, reg, val); + tgen_arithi(s, ARITH_ADD, reg, val, 0); } static void tcg_out_jxx(TCGContext *s, int opc, int label_index) @@ -344,7 +350,7 @@ static void tcg_out_brcond(TCGContext *s, int cond, /* test r, r */ tcg_out_modrm(s, 0x85, arg1, arg1); } else { - tgen_arithi(s, ARITH_CMP, arg1, arg2); + tgen_arithi(s, ARITH_CMP, arg1, arg2, 0); } } else { tcg_out_modrm(s, 0x01 | (ARITH_CMP << 3), arg2, arg1); @@ -961,7 +967,7 @@ static inline void tcg_out_op(TCGContext *s, int opc, c = ARITH_ADD; gen_arith: if (const_args[2]) { - tgen_arithi(s, c, args[0], args[2]); + tgen_arithi(s, c, args[0], args[2], 0); } else { tcg_out_modrm(s, 0x01 | (c << 3), args[2], args[0]); } @@ -1019,21 +1025,21 @@ static inline void tcg_out_op(TCGContext *s, int opc, case INDEX_op_add2_i32: if (const_args[4]) - tgen_arithi(s, ARITH_ADD, args[0], args[4]); + tgen_arithi(s, ARITH_ADD, args[0], args[4], 1); else tcg_out_modrm(s, 0x01 | (ARITH_ADD << 3), args[4], args[0]); if (const_args[5]) - tgen_arithi(s, ARITH_ADC, args[1], args[5]); + tgen_arithi(s, ARITH_ADC, args[1], args[5], 1); else tcg_out_modrm(s, 0x01 | (ARITH_ADC << 3), args[5], args[1]); break; case INDEX_op_sub2_i32: if (const_args[4]) - tgen_arithi(s, ARITH_SUB, args[0], args[4]); + tgen_arithi(s, ARITH_SUB, args[0], args[4], 1); else tcg_out_modrm(s, 0x01 | (ARITH_SUB << 3), args[4], args[0]); if (const_args[5]) - tgen_arithi(s, ARITH_SBB, args[1], args[5]); + tgen_arithi(s, ARITH_SBB, args[1], args[5], 1); else tcg_out_modrm(s, 0x01 | (ARITH_SBB << 3), args[5], args[1]); break; |