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authorAurelien Jarno <aurelien@aurel32.net>2009-09-27 19:57:43 +0200
committerAurelien Jarno <aurelien@aurel32.net>2009-09-27 20:00:39 +0200
commit17cf428f2e1f6970296b4c0ddcb054e4bc3f2355 (patch)
tree28b2e4ca460c386ed433de3f9b49356675007bc2 /tcg/i386
parentb70650cbfea324438f55c2269138dd7f4e7cf086 (diff)
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>
Diffstat (limited to 'tcg/i386')
-rw-r--r--tcg/i386/tcg-target.c24
1 files changed, 15 insertions, 9 deletions
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index d318443ff1..b4e3b6fd47 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;