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Reduce space required by instruction width

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This commit is contained in:
Alexis Engelke
2019-01-13 14:26:26 +01:00
parent c05b555bb0
commit 80458e3288
3 changed files with 13 additions and 11 deletions
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16
decode.c
View File

@@ -567,35 +567,37 @@ decode(const uint8_t* buffer, int len, DecodeMode mode, Instr* instr)
instr->segment = RI_DS; instr->segment = RI_DS;
} }
uint8_t op_size = 0; uint8_t op_size_log = 0;
if (desc->gp_size_8) if (desc->gp_size_8)
{ {
op_size = 1; op_size_log = 1;
} }
#if defined(ARCH_X86_64) #if defined(ARCH_X86_64)
else if (prefixes & PREFIX_REXW) else if (prefixes & PREFIX_REXW)
{ {
op_size = 8; op_size_log = 4;
} }
#endif #endif
else if (prefixes & PREFIX_OPSZ) else if (prefixes & PREFIX_OPSZ)
{ {
op_size = 2; op_size_log = 2;
} }
#if defined(ARCH_X86_64) #if defined(ARCH_X86_64)
else if (mode == DECODE_64 && desc->gp_size_def64) else if (mode == DECODE_64 && desc->gp_size_def64)
{ {
op_size = 8; op_size_log = 4;
} }
#endif #endif
else else
{ {
op_size = 4; op_size_log = 3;
} }
uint8_t op_size = (1 << op_size_log) >> 1;
if (UNLIKELY(desc->gp_instr_width)) if (UNLIKELY(desc->gp_instr_width))
{ {
instr->width = op_size; instr->width = op_size_log;
} }
else else
{ {

4
decode.h
View File

@@ -117,7 +117,7 @@ struct Instr
uint16_t type; uint16_t type;
struct Operand operands[4]; struct Operand operands[4];
uint8_t segment : 3; uint8_t segment : 3;
uint8_t width : 5; uint8_t width : 3;
/** /**
* Encoded as 1 << (scale - 1) **or** no scaled register at all if zero. * Encoded as 1 << (scale - 1) **or** no scaled register at all if zero.
@@ -136,7 +136,7 @@ struct Instr
typedef struct Instr Instr; typedef struct Instr Instr;
#define INSTR_SEGMENT(instr) ((instr)->segment) #define INSTR_SEGMENT(instr) ((instr)->segment)
#define INSTR_WIDTH(instr) ((instr)->width) #define INSTR_WIDTH(instr) ((1 << (instr)->width) >> 1)
#define INSTR_HAS_REP(instr) ((instr)->prefixes & PREFIX_REP) #define INSTR_HAS_REP(instr) ((instr)->prefixes & PREFIX_REP)
#define INSTR_HAS_REPNZ(instr) ((instr)->prefixes & PREFIX_REPNZ) #define INSTR_HAS_REPNZ(instr) ((instr)->prefixes & PREFIX_REPNZ)
#define INSTR_HAS_LOCK(instr) ((instr)->prefixes & PREFIX_LOCK) #define INSTR_HAS_LOCK(instr) ((instr)->prefixes & PREFIX_LOCK)

4
format.c
View File

@@ -83,10 +83,10 @@ instr_format(const Instr* instr, char buffer[128])
*(cur++) = *(mnemonic++); *(cur++) = *(mnemonic++);
} }
if (instr->width != 0) if (INSTR_WIDTH(instr))
{ {
*(cur++) = '_'; *(cur++) = '_';
instr_format_decimal(&cur, instr->width); instr_format_decimal(&cur, INSTR_WIDTH(instr));
} }
for (int i = 0; i < 4; i++) for (int i = 0; i < 4; i++)