9. P-code Tables
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## 9. P-code Tables

We list all the p-code operations by name along with the syntax for invoking them within the semantic section of a constructor definition (see Section 7.7, “The Semantic Section”), and with a description of the operator. The terms v0 and v1 represent identifiers of individual input varnodes to the operation. In terms of syntax, v0 and v1 can be replaced with any semantic expression, in which case the final output varnode of the expression becomes the input to the operator. The term spc represents the identifier of an address space, which is a special input to the LOAD and STORE operations. The identifier of any address space can be used.

This table lists all the operators for building semantic expressions. The operators are listed in order of precedence, highest to lowest.

Table 5. Semantic Expression Operators and Syntax

P-code Name | SLEIGH Syntax | Description
`SUBPIECE` |
`v0:2`
`v0(2)`
| The least significant n bytes of v0. Truncate least significant n bytes of v0. Most significant bytes may be truncated depending on result size.
`POPCOUNT` | `popcount(v0)` | Count the number of 1 bits in v0.
`LZCOUNT` | `lzcount(v0)` | Count the number of leading 0 bits in v0.
`(simulated)` | `v0[6,1]` | Extract a range of bits from v0, putting result in a minimum number of bytes. The bracketed numbers give respectively, the least significant bit and the number of bits in the range.
`LOAD` |
`* v1`
`*[spc]v1`
`*:2 v1`
`*[spc]:2 v1`
| Dereference v1 as pointer into default space. Optionally specify space to load from and size of data in bytes.
`BOOL_NEGATE` | `!v0` | Negation of boolean value v0.
`INT_NEGATE` | `~v0` | Bitwise negation of v0.
`INT_2COMP` | `-v0` | Twos complement of v0.
`FLOAT_NEG` | `f- v0` | Additive inverse of v0 as a floating-point number.
`INT_MULT` | `v0 * v1` | Integer multiplication of v0 and v1.
`INT_DIV` | `v0 / v1` | Unsigned division of v0 by v1.
`INT_SDIV` | `v0 s/ v1` | Signed division of v0 by v1.
`INT_REM` | `v0 % v1` | Unsigned remainder of v0 modulo v1.
`INT_SREM` | `v0 s% v1` | Signed remainder of v0 modulo v1.
`FLOAT_DIV` | `v0 f/ v1` | Division of v0 by v1 as floating-point numbers.
`FLOAT_MULT` | `v0 f* v1` | Multiplication of v0 and v1 as floating-point numbers.
`INT_ADD` | `v0 + v1` | Addition of v0 and v1 as integers.
`INT_SUB` | `v0 - v1` | Subtraction of v1 from v0 as integers.
`FLOAT_ADD` | `v0 f+ v1` | Addition of v0 and v1 as floating-point numbers.
`FLOAT_SUB` | `v0 f- v1` | Subtraction of v1 from v0 as floating-point numbers.
`INT_LEFT` | `v0 << v1` | Left shift of v0 by v1 bits.
`INT_RIGHT` | `v0 >> v1` | Unsigned (logical) right shift of v0 by v1 bits.
`INT_SRIGHT` | `v0 s>> v1` | Signed (arithmetic) right shift of v0 by b1 bits.
`INT_SLESS` |
`v0 s< v1`
`v1 s> v0`
| True if v0 is less than v1 as a signed integer.
`INT_SLESSEQUAL` |
`v0 s<= v1`
`v1 s>= v0`
| True if v0 is less than or equal to v1 as a signed integer.
`INT_LESS` |
`v0 < v1`
`v1 > v0`
| True if v0 is less than v1 as an unsigned integer.
`INT_LESSEQUAL` |
`v0 <= v1`
`v1 >= v0`
| True if v0 is less than or equal to v1 as an unsigned integer.
`FLOAT_LESS` |
`v0 f< v1`
`v1 f> v0`
| True if v0 is less than v1 viewed as floating-point numbers.
`FLOAT_LESSEQUAL` |
`v0 f<= v1`
`v1 f>= v0`
| True if v0 is less than or equal to v1 as floating-point.
`INT_EQUAL` | `v0 == v1` | True if v0 equals v1.
`INT_NOTEQUAL` | `v0 != v1` | True if v0 does not equal v1.
`FLOAT_EQUAL` | `v0 f== v1` | True if v0 equals v1 viewed as floating-point numbers.
`FLOAT_NOTEQUAL` | `v0 f!= v1` | True if v0 does not equal v1 viewed as floating-point numbers.
`INT_AND` | `v0 & v1` | Bitwise Logical And of v0 with v1.
`INT_XOR` | `v0 ^ v1` | Bitwise Exclusive Or of v0 with v1.
`INT_OR` | `v0 | v1` | Bitwise Logical Or of v0 with v1.
`BOOL_XOR` | `v0 ^^ v1` | Exclusive-Or of booleans v0 and v1.
`BOOL_AND` | `v0 && v1` | Logical-And of booleans v0 and v1.
`BOOL_OR` | `v0 || v1` | Logical-Or of booleans v0 and v1.
`INT_ZEXT` | `zext(v0)` | Zero extension of v0.
`INT_SEXT` | `sext(v0)` | Sign extension of v0.
`INT_CARRY` | `carry(v0,v1)` | True if adding v0 and v1 would produce an unsigned carry.
`INT_SCARRY` | `scarry(v0,v1)` | True if adding v0 and v1 would produce a signed carry.
`INT_SBORROW` | `sborrow(v0,v1)` | True if subtracting v1 from v0 would produce a signed borrow.
`FLOAT_NAN` | `nan(v0)` | True if v0 is not a valid floating-point number (NaN).
`FLOAT_ABS` | `abs(v0)` | Absolute value of v0 as floating point number.
`FLOAT_SQRT` | `sqrt(v0)` | Square root of v0 as floating-point number.
`INT2FLOAT` | `int2float(v0)` | Floating-point representation of v0 viewed as an integer.
`FLOAT2FLOAT` | `float2float(v0)` | Copy of floating-point number v0 with more or less precision.
`TRUNC` | `trunc(v0)` | Signed integer obtained by truncating v0.
`FLOAT_CEIL` | `ceil(v0)` | Nearest integer greater than v0.
`FLOAT_FLOOR` | `floor(v0)` | Nearest integer less than v0.
`FLOAT_ROUND` | `round(v0)` | Nearest integer to v0.
`CPOOLREF` | `cpool(v0,...)` | Access value from the constant pool.
`NEW` | `newobject(v0)` | Allocate object of type described by v0.
`CALLOTHER` | `ident(v0,...)` | User defined operator ident, with functional syntax.

The following table lists the basic forms of a semantic statement.

Table 6. Basic Statements and Associated Operators

P-code Name | SLEIGH Syntax | Description
`COPY, other` | `v0 = v1;` | Assignment of v1 to v0.
`STORE` |
`*v0 = v1`
`*[spc]v0 = v1;`
`*:4 v0 = v1;`
`*[spc]:4 v0 = v1;`
| Store v1 in default space using v0 As pointer. Optionally specify space to store in and size of data in bytes.
`CALLOTHER` | `ident(v0,...);` | Invoke user-defined operation ident as a standalone statement, with no output.
| `v0[8,1] = v1;` | Fill a bit range within v0 using v1, leaving the rest of v0 unchanged.
| `ident(v0,...);` | Invoke the macro named ident.
| `build ident;` | Execute the p-code to build operand ident.
| `delayslot(1);` | Execute the p-code for the following instruction.

The following table lists the branching operations and the statements which invoke them.

Table 7. Branching Statements

P-code Name | SLEIGH Syntax | Description
`BRANCH` | `goto v0;` | Branch execution to address of v0.
`CBRANCH` | `if (v0) goto v1;` | Branch execution to address of v1 if v0 equals 1 (true).
`BRANCHIND` | `goto [v0];` | Branch execution to v0 viewed as an offset in current space.
`CALL` | `call v0;` | Branch execution to address of v0. Hint that branch is subroutine call.
`CALLIND` | `call [v0];` | Branch execution to v0 viewed as an offset in current space. Hint that branch is subroutine call.
`RETURN` | `return [v0];` | Branch execution to v0 viewed as an offset in current space. Hint that branch is a subroutine return.

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